Configuration

cluster

cluster.name

Type	Default
string	`emqxcl`

Description

Cluster name.

cluster.proto_dist

Type	Optional Value	Default
enum	`inet_tcp`, `inet6_tcp`, `inet_tls`	`inet_tcp`

Description

Distributed Erlang cluster protocol type. Available values are:

inet_tcp: using IPv4
inet6_tcp: using IPv6
inet_tls: using TLS, required to be used with node.ssl_dist_optfile configuration

cluster.discovery

Type	Optional Value	Default
enum	`manual`, `static`, `mcast`, `dns`, `etcd`, `k8s`	`manual`

Description

Cluster node discovery method. Available values are:

manual: join the cluster manually
static: Configure static nodes. Configure several fixed nodes, and the new node joins the cluster by connecting one of the fixed nodes.
mcast: Use UDP multicast to discover nodes.
dns: Use DNS A records to discover nodes.
etcd: Use etcd to discover nodes.
k8s: Use Kubernetes to discover nodes.

cluster.autoheal

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Enable or disable the automatic recovery mechanism of cluster brain splitting.

cluster.autoclean

Type	Default
duration	`5m`

Description

Specify how long to delete short-line nodes from the cluster.

cluster.static.seeds

Type	Default	Example
string	-	`emqx1@192.168.0.100,emqx2@192.168.0.101`

Description

When using static clustering, specify a fixed list of nodes, separated by commas , between multiple nodes.

cluster.mcast.addr

Type	Default
ipaddr	`239.192.0.1`

Description

When using the mcast cluster, specify the multicast address.

cluster.mcast.ports

Type	Default
string	`4369`

Description

When using the mcast cluster, specify the multicast port. If there are multiple ports, separate them with commas ,.

cluster.mcast.iface

Type	Default
ipaddr	`0.0.0.0`

Description

When using mcast cluster, specify which local IP address the node discovery service needs to bind to.

cluster.mcast.ttl

Type	Default
integer	255

Description

When using mcast cluster, specify the Time-To-Live value of multicast.

cluster.mcast.loop

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

When using mcast clustering, set whether multicast packets are delivered to the local loopback address.

cluster.dns.name

Type	Default	Example
string	-	`mycluster.com`

Description

When using the dns cluster, specify the name of the DNS A record. emqx will access the DNS A record to obtain a list of IP addresses, and then splice the APP name specified in cluster.dns.app to get a list of all nodes in the cluster.

Example

Set cluster.dns.app = emqx, and configure a DNS: mycluster.com, which points to 3 IP addresses:

192.168.0.100
192.168.0.101
192.168.0.102

Then get the list of cluster nodes as follows:

emqx@192.168.0.100
emqx@192.168.0.101
emqx@192.168.0.102

cluster.dns.app

Type	Default	Example
string	-	`emqx`

Description

When using dns cluster, it is used to splice the IP list obtained from cluster.dns.name to get a list of node names.

cluster.etcd.server

Type	Default	Example
string	-	`http://127.0.0.1:2379`

Description

When using etcd cluster, specify the address of etcd service. If there are multiple services, use commas to separate them.

cluster.etcd.prefix

Type	Default	Example
string	-	`emqxcl`

Description

When using etcd cluster, specify the prefix of etcd path. Each node creates a path in etcd:

v2/keys/<prefix>/<cluster.name>/<node.name>

cluster.etcd.node_ttl

Type	Default	Example
duration	-	`1m`

Description

When using etcd cluster, specify the expiration time of the node path in etcd.

cluster.etcd.ssl.keyfile

Type	Default	Example
string	-	`etc/certs/client-key.pem`

Description

When using SSL to connect to etcd, specify the client's private key file.

cluster.etcd.ssl.certfile

Type	Default	Example
string	-	`etc/certs/client.pem`

Description

When using SSL to connect to etcd, specify the SSL client certificate file.

cluster.etcd.ssl.cacertfile

Type	Default	Example
string	-	`etc/certs/ca.pem`

Description

When using SSL to connect to etcd, specify the CA certificate file for SSL.

cluster.k8s.apiserver

Type	Default	Example
string	-	`http://10.110.111.204:8080`

Description

When using the k8s cluster, specify the Kubernetes API Server. If there are multiple Servers, separate them with commas ,.

cluster.k8s.service_name

Type	Default	Example
string	-	`emqx`

Description

When using k8s cluster, specify the service name of EMQ X Broker in Kubernetes.

cluster.k8s.address_type

Type	Optional Value	Default
enum	`ip`, `dns`, `hostname`	`ip`

Description

When using k8s cluster, address_type is used to obtain the host list from the response of the Kubernetes interface.

Example

Specifying cluster.k8s.address_type as ip, it will get the list of IP addresses of emqx services from the Kubernetes interface:

172.16.122.31
172.16.122.32
172.16.122.33

Then splice with the app name specified by cluster.k8s.app_name configuration to get a list of emqx nodes:

emqx@172.16.122.31
emqx@172.16.122.32
emqx@172.16.122.33

cluster.k8s.app_name

Type	Default	Example
string	-	`emqx`

Description

When using k8s clustering, app_name is used to splice with the obtained Host list to get the node list.

cluster.k8s.suffix

Type	Default	Example
string	-	`pod.cluster.local`

Description

When using the k8s method and specifying cluster.k8s.address_type as the dns type, you can set the suffix of the emqx node name, and splice with cluster.k8s.namespace to get a list of node names.

cluster.k8s.namespace

Type	Default	Example
string	-	`default`

Description

When using the k8s method and specifying cluster.k8s.address_type as the dns type, you can set the namespace of the emqx node name, and splice with cluster.k8s.suffix to get a list of node names.

Example

Setting cluster.k8s.address_type to dns, you will get the dns list of emqx service from the Kubernetes interface:

172-16-122-31
172-16-122-32
172-16-122-33

Then splice with cluster.k8s.app_name = emqx，cluster.k8s.suffix = pod.cluster.local，cluster.k8s.namespace = default to get a list of emqx node names in the form of dns:

emqx@172-16-122-31.default.pod.cluster.local
emqx@172-16-122-32.default.pod.cluster.local
emqx@172-16-122-33.default.pod.cluster.local

node.name

Type	Default
string	`emqx@127.0.0.1`

Description

The node name. The format is <name> @ <host>. Where <host> can be an IP address or FQDN. See http://erlang.org/doc/reference_manual/distributed.html for details

Type	Default
string	`emqxsecretcookie`

Description

The cookie value used by the distributed Erlang cluster.

node.data_dir

Type	Default
folder	`./data`

Description

The node's data directory, which is used to store Mnesia data files.

node.heartbeat

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

System tuning parameters. This configuration will override the -heart parameter in the vm.args file.

Enable or disable Erlang runtime detection mechanism, and restart automatically when the runtime terminates. Use with care to avoid restarting the monitored process when emqx is closed manually.

node.async_threads

Type	Optional Value	Default
integer	0 - 1024	4

Description

System tuning parameters. This configuration will override the +A parameter in the vm.args file.

Set the number of threads in the asynchronous thread pool in Erlang runtime, see http://erlang.org/doc/man/erl.html for details.

node.process_limit

Type	Optional Value	Default
integer	1024 - 134217727	2097152

Description

System tuning parameters. This configuration will override the +P parameter in the vm.args file.

Set the maximum number of processes allowed by Erlang, which will affect the number of connections that emqx nodes can process. See http://erlang.org/doc/man/erl.html for details.

node.max_ports

Type	Optional Value	Default
integer	1024 - 134217727	1048576

Description

System tuning parameters. This configuration will override the +Q parameter in the vm.args file.

Set the maximum number of ports allowed by Erlang. See http://erlang.org/doc/man/erl.html for details.

node.dist_buffer_size

Type	Optional Value	Default
bytesize	1KB - 2GB	`8MB`

Description

System tuning parameters. This configuration will override the +zdbbl parameter in the vm.args file.

Set the maximum cache size used by Erlang distributed communication. See http://erlang.org/doc/man/erl.html for details.

node.max_ets_tables

Type	Default
integer	262144

Description

System tuning parameters. This configuration will override the +e parameter in the vm.args file.

Set the maximum number of ETS tables allowed in Erlang runtime. See http://erlang.org/doc/man/erl.html for details.

node.global_gc_interval

Type	Default
duration	`15m`

Description

System tuning parameters, which set how often Erlang runs to force a global garbage collection.

node.fullsweep_after

Type	Optional Value	Default
integer	0 - 65535	1000

Description

System tuning parameters. This configuration will override the -env ERL_FULLSWEEP_AFTER parameter in the vm.args file.

Set how many times the generational GC will run before Erlang runs a fullsweep GC. For details, see http://erlang.org/doc/man/erlang.html#spawn_opt-4.

node.crash_dump

Type	Default
string	`log/crash.dump`

Description

Set the storage path and file name of the Erlang crash_dump file.

node.ssl_dist_optfile

Type	Default
string	`etc/ssl_dist.conf`

Description

This configuration will override the -ssl_dist_optfile parameter in the vm.args file.

If you use SSL to establish an emqx cluster, you need to specify the SSL distributed protocol configuration file. It needs to be used with cluster.proto_dist = inet_tls.

node.dist_net_ticktime

Type	Default
integer	120

Description

System tuning parameters. This configuration will override the -kernel net_ticktime parameter in the vm.args file.

Specifying how long time when a node has been unresponsive, it is considered to be down and disconnected. For details, see http://www.erlang.org/doc/man/kernel_app.html#net_ticktime.

node.dist_listen_min

Type	Optional Value	Default
integer	1024 - 65535	6369

Description

Set a TCP port range together with node.dist_listen_max. This port ranget is used for distribution to distributed Erlang as a listening port for distributed channels. Note that if a firewall is set between nodes, this port range needs to be placed into the firewall's whitelist.

node.dist_listen_max

Type	Optional Value	Default
integer	1024 - 65535	6369

Description

Set a TCP port range together with node.dist_listen_min. This port range is used for distribution to distributed Erlang as a listening port for distributed channels. Note that if a firewall is set up between nodes, this port rangeneeds to be put in The firewall's whitelist.

rpc.mode

Type	Optional Value	Default
enum	`sync`, `async`	`async`

Description

RPC mode. Synchronous or asynchronous mode is optional.

rpc.async_batch_size

Type	Default
integer	256

Description

The maximum number of batch messages sent in asynchronous mode. Note that this configuration does not work in synchronous mode.

node.tcp_server_port

Type	Optional Value	Default
integer	1024 - 65535	5369

Description

Set the listening port used by RPC local service

node.tcp_client_port

Type	Optional Value	Default
integer	1024-65535	5369

Description

Set the port of the remote RPC service.

node.tcp_client_num

Type	Optional Value	Default
integer	1 - 256	CPU core number / 2

Description

Set the number of RPC communication channels initiated by this node to each remote node. Set to 1 to ensure the order of messages. Keep the default value (half the number of CPU cores) to improve RPC throughput.

rpc.connect_timeout

Type	Default
duration	`5s`

Description

Timeout for establishing an RPC connection. It means how long will it give up after trying if the remote node does not respond when establishing a connection, .

rpc.send_timeout

Type	Default
duration	`5s`

Description

Timeout for sending, which means how long to give up after sending the message.

rpc.authentication_timeout

Type	Default
duration	`5s`

Description

RPC authentication timeout. It means how long it will give up if the remote node does not respond, .

rpc.call_receive_timeout

Type	Default
duration	`15s`

Description

The timeout period of RPC synchronous mode. It means how long it will take before giving up if the RPC synchronous call fails to receive a reply.

rpc.socket_keepalive_idle

Type	Default
duration	`900s`

Description

It means how long after the last packet was sent, keepalive probe packets are sent.

rpc.socket_keepalive_interval

Type	Default
duration	`75s`

Description

The interval between keepalive detection messages.

rpc.socket_keepalive_count

Type	Default
integer	9

Description

For how many times if the keepalive probe message fails to receive a reply, the RPC connection is considered lost.

rpc.socket_sndbuf

Type	Default
bytesize	`1MB`

Description

TCP tuning parameters. TCP sending buffer size.

rpc.socket_recbuf

Type	Default
bytesize	`1MB`

Description

TCP tuning parameters. TCP receiving buffer size.

rpc.socket_buffer

Type	Default
bytesize	`1MB`

Description

TCP tuning parameters. Socket buffer size in user mode.

log.to

Type	Optional Value	Default
enum	`off`, `file`, `console`, `both`	`both`

Description

Where to output the log. The optional values are:

off: Disable logging completely
file: Only output log to file
console: Only output logs to standard output (emqx console)
both: output log to file and standard output at the same time (emqx console)

log.level

Type	Optional Value	Default
enum	`debug`, `info`, `notice`, `warning`</>`error`, `critical`, `alert`, `emergency`	`warning`

Description

Global log level. This includes the primary log level and all log handlers. For details, see log level and log handlers.

log.dir

Type	Default
dir	`./log`

Description

Log file directory.

log.file

Type	Default
string	`emqx.log`

Description

The prefix of the log file. For example, if you use the default value (log.file = emqx.log), the log file name will be emqx.log.1, emqx.log.2, ...

log.chars_limit

Type	Default
integer	-1

Description

Set the maximum length of a single log message. If this length is exceeded, the log message will be truncated. -1 means no limit.

log.rotation.size

Type	Default
bytesize	`10MB`

Description

Set the size of a single log file. If it exceeds this size, the log file will be rolled to create a new log file.

log.rotation.count

Type	Default
integer	5

Description

Set the total number of log files. If this number is exceeded, the next log file will overwrite the first file.

log.<level>.file

Type	Default
string	-

Description

Set a separate log file for a certain log level.

Example

Separately output info and above logs to info.log.N file:

log.info.file = info.log

Output error and error logs separately to the error.log.N file

log.error.file = error.log

allow_anonymous

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to allow anonymous users to log in to the system.

Tip

It is recommended to disable this option in the production environment.

acl_nomatch

Type	Optional Value	Default
enum	`allow`, `deny`	`allow`

Description

When the ACL is not hit, allow or deny the publish/subscribe operation.

acl_file

Type	Default
string	`etc/acl.conf`

Description

The default path of ACL file.

enable_acl_cache

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable ACL caching.

acl_cache_max_size

Type	Default
integer	32

Description

Maximum cache number of ACL rule.

acl_cache_ttl

Type	Default
duration	`1m`

Description

Maximum cache time of ACL rule.

acl_deny_action

Type	Optional Value	Default
enum	`ignore`, `disconnect`	`ignore`

Description

What to do after the ACL check fails.

ignore：No operation
disconnect：disconnect.

flapping_detect_policy

Type	Default
string	`30, 1m, 5m`

Description

Specify the Flapping inspection strategy.

Format: <threshold>,<duration>,<banned>.

For example, 30, 1m, 5m, it means that if the client disconnects 30 times within 1 minute, then login is prohibited for the next 5 minutes

mqtt.max_packet_size

Type	Default
bytesize	`1MB`

Description

The maximum allowed length of MQTT messages.

mqtt.max_clientid_len

Type	Default
integer	65535

Description

The maximum allowed length of Client ID string.

mqtt.max_topic_levels

Type	Default
integer	0

Description

The maximum allowed level of topics for client subscription. 0 means no limit.

mqtt.max_qos_allowed

Type	Optional Value	Default
enum	`0`, `1`, `2`	`2`

Description

The maximum allowed QoS level for client to publish.

mqtt.max_topic_alias

Type	Default
integer	65535

Description

The maximum allowed number of topic aliases. 0 means that topic aliases are not supported.

mqtt.retain_available

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to support Retain message.

mqtt.wildcard_subscription

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to support subscribing to wildcard topics.

mqtt.shared_subscription

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to support shared subscriptions.

mqtt.ignore_loop_deliver

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to ignore the message sent by itself. If it is ignored, it means that EMQ X Broker will not deliver this message to the sender of the message.

mqtt.strict_mode

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to enable the strict check mode. The strict check mode will check the correctness of the MQTT message in more detail.

zone.external.idle_timeout

Type	Default
duration	`15s`

Description

The daze time after the TCP connection is established. If no packets are received within this time, the connection will be shutdown.

zone.external.enable_acl

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable ACL check.

zone.external.enable_ban

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable blacklist.

zone.external.enable_stats

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable client status statistics.

zone.external.acl_deny_action

| Type | Optional Value | Default | | ---- | -------------------- - | -------- | | enum | ignore, disconnect | ignore |

Description

What to do after the ACL check fails.

ignore：No any operation.
disconnect：disconnect.

zone.external.force_gc_policy

Type	Default
string	`16000

Description

When a certain number of messages, or bytes, are received, a garbage collection is forced.

Format: <Number> | <Bytes>.

For example, 16000|16MB means that when 16000 messages are received, or a byte of 16MB flows in, a garbage collection is forced.

zone.external.force_shutdown_policy

Type	Default
string	-

Description

When the process message queue length, or the memory bytes reaches a certain value, the process is forced to close.

The "message queue" here refers to the "message mailbox" of the Erlang process, not the "mqueue" of QoS 1 and QoS 2.

Format: <Number> | <Bytes>.

For example, 32000|32MB means that when the process accumulates 32000 messages, or the process occupies memory up to 32MB, the process is closed.

zone.external.max_packet_size

Type	Default
bytesize	-

Description

The maximum allowed length of MQTT packet.

zone.external.max_clientid_len

Type	Default
integer	-

Description

The maximum length of Client ID string.

zone.external.max_topic_levels

Type	Default
integer	-

Description

The maximum allowed level of topics for client subscription. 0 means no limit.

zone.external.max_qos_allowed

Type	Optional Value	Default
enum	`0`, `1`, `2`	-

Description

The maximum QoS level allowed for the client to publish.

zone.external.max_topic_alias

Type	Default
integer	-

Description

The maximum number of topic aliases. 0 means that topic aliases are not supported.

zone.external.retain_available

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to support Retain message.

zone.external.wildcard_subscription

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to support subscribing to wildcard topics.

zone.external.shared_subscription

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to support shared subscriptions.

zone.external.server_keepalive

Type	Default
integer	-

Description

Keepalive time specified by the server, used for MQTT v5.0 CONNACK messages

zone.external.keepalive_backoff

Type	Optional Value	Default
float	> 0.5	0.75

Description

Keepalive backoff index. If no data packet is received from the client within the time of Keepalive * backoff * 2, it is considered that the client has heartbeat timeout.

zone.external.max_subscriptions

Type	Default
integer	0

Description

The maximum number of topics that a single client is allowed to subscribe to. 0 means no limit.

zone.external.upgrade_qos

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Allow EMQ X Broker to force the QoS level of the message upgrading to the subscribed QoS level when publishing the message.

zone.external.max_inflight

Type	Default
integer	32

Description

Inflight window size: The inflight window is used to store unacknowledged QoS 1 and QoS 2 messages.

zone.external.retry_interval

Type	Default
duration	`30s`

Description

Message retransmission interval: EMQ X Broker checks whether message retransmission is required at each interval.

zone.external.max_awaiting_rel

Type	Default
integer	100

Description

The maximum receiving window for QoS 2 messages, which configures how many QoS 2 messages from the client can be processed by EMQ X Broker simultaneously. 0 means no limit.

zone.external.await_rel_timeout

Type	Default
duration	`300s`

Description

Time for QoS 2 message processing timeout. If the QoS PUBREL message has not been received after the timeout, the message is dropped from the receiving window.

zone.external.session_expiry_interval

Type	Default
duration	`2h`

Description

The default timeout period of the session, which is mainly used for MQTT v3.1 and v3.1.1 protocols. In MQTT v5.0, this value is usually carried in the client's connection message.

zone.external.max_mqueue_len

Type	Default
integer	1000

Description

The maximum length of the message queue. When the flight window is full, or the client is offline, the message will be stored in the queue. 0 means no limit.

zone.external.mqueue_priorities

Type	Optional Value	Default
string	`none`, `<Spec>`	`none`

Description

Queue message priority configuration:

none：no prioritization.
<Spec>：A message priority table, which configures the priority of messages under a certain topic. For example:
- topic/1=10: indicates that the message priority of the topic topic/1 is 10.
- topic/1=10,topic/2=8: indicates that the priority of two topics is configured, which are 10 and 8 respectively.
- Among them, the higher the priority value, the higher the priority level.

When the length of the message queue is limited, low priority messages will be dropped first.

zone.external.mqueue_default_priority

Type	Optional Value	Default
enum	`highest`, `lowest`	`highest`

Description

The default priority level of the message.

zone.external.mqueue_store_qos0

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether the message queue stores QoS 0 messages.

zone.external.enable_flapping_detect

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to enable Flapping check.

zone.external.mountpoint

Type	Default
string	-

Description

After topic mount point is configured, all subscribed and published topics will be prefixed by EMQ X Broker.

The available placeholders are:

%c：Client ID.
%u：Username.

For example, if the mount point is set to user/%c/. , when the client with client ID tom publishes the topic open message, the topic actually routed in EMQ X Broker is user/tom/open.

zone.external.use_username_as_clientid

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to use the client's Username as its Client ID.

zone.external.ignore_loop_deliver

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to ignore the message sent by yourself. If ignored, it means that EMQ X Broker will not deliver this message to the sender of the message.

zone.external.strict_mode

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to enable the strict check mode. The strict check mode will check the correctness of the MQTT message in more detail.

zone.internal.allow_anonymous

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to allow anonymous users to log in to the system.

zone.internal.enable_stats

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable client status statistics.

zone.internal.enable_acl

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to enable ACL check.

zone.internal.acl_deny_action

Type	Optional Value	Default
enum	`ignore`, `disconnect`	`ignore`

Description

What to do after the ACL check fails.

ignore：No operation.
disconnect：Disconnect.

zone.internal.force_gc_policy

Type	Default
string	-

Description

When a certain number of messages, or bytes, are received, a garbage collection is forced.

Format: <Number> | <Bytes>.

For example, 16000|16MB means that when 16000 messages are received, or a byte of 16MB flows in, a garbage collection is forced.

zone.internal.wildcard_subscription

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to support subscribing to wildcard topics.

zone.internal.shared_subscription

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to support shared subscriptions.

zone.internal.max_subscriptions

Type	Default
integer	0

Description

The maximum number of topics that a single client is allowed to subscribe to. 0 means no limit.

zone.internal.max_inflight

Type	Default
integer	128

Description

Inflight window size: The flight window is used to store unanswered QoS 1 and QoS 2 messages.

zone.internal.max_awaiting_rel

Type	Default
integer	1000

Description

The maximum receiving window for QoS 2 messages, that configures how many QoS 2 messages from the client can be processed by EMQ X Broker simultaneously. 0 means no limit.

zone.internal.max_mqueue_len

Type	Default
integer	10000

Description

The maximum length of the message queue. When the flight window is full, or the client is offline, the message will be stored in the queue. 0 means no limit.

``zone.internal.mqueue_store_qos0

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether the message queue stores QoS 0 messages.

zone.internal.enable_flapping_detect

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to enable Flapping check.

zone.internal.force_shutdown_policy

Type	Default
string	-

Description

When the process message queue length, or the memory bytes reaches a certain value, the process is forced to close.

The "message queue" here refers to the "message mailbox" of the Erlang process, not the "mqueue" of QoS 1 and QoS 2.

Format: <Number> | <Bytes>.

For example, 32000|32MB means that when the process accumulates 32000 messages, or the process occupies memory up to 32MB, the process is closed.

zone.internal.mountpoint

Type	Default
string	-

Description

After topic mount point is configured, all subscribed and published topics will be prefixed by EMQ X Broker.

The available placeholders are:

%c：Client ID.
%u：Username.

For example, if the mount point is set to user/%c/. , when the client with client ID tom publishes the topic open message, the topic actually routed in EMQ X Broker is user/tom/open.

zone.internal.ignore_loop_deliver

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to ignore the message sent by itself. If ignored, it means that EMQ X Broker will not deliver this message to the sender of the message.

zone.internal.strict_mode

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to enable the strict check mode. The strict check mode will check the correctness of the MQTT message in more detail.

zone.internal.bypass_auth_plugins

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to allow clients under this zone to bypass the authentication step of the authentication plugin.

listener.tcp.external

Type	Default
string	`0.0.0.0:1883`

Description

Configure the listening address of the MQTT / TCP listener named external.

Example

1883: monitors IPv4 0.0.0.0: 1883. 127.0.0.1: 1883: monitor address is 1883 port on the 127.0.0.1 network card. :: 1: 1883: monitors the IPv6 address as 1883 port on the :: 1 network card.

listener.tcp.external.acceptors

Type	Default
integer	8

Description

The size of the listener's receiving pool.

listener.tcp.external.max_connections

Type	Default
integer	1024000

Description

The maximum number of concurrent connections allowed by the listener.

listener.tcp.external.max_conn_rate

Type	Default
integer	1000

Description

The maximum access rate allowed by the listener. Unit: pcs / sec

listener.tcp.external.active_n

Type	Default
integer	100

Description

The number of times the listener continues to receive TCP packets.

listener.tcp.external.zone

Type	Default
string	`external`

Description

The configuration zone to which the listener belongs.

listener.tcp.external.rate_limit

Type	Default
string	-

Description

The rate limit of the listener. The format is <limit>,<duration>.

Example

100KB,10s：Limit the number of incoming bytes within 10 seconds not to exceed 100 KB.

listener.tcp.external.access.1

Type	Default
string	`allow all`

Description

List of ACL rules of the listener. It is used to set the white/black list of the connection layer.

Example

allow all：Allow all TCP connections. allow 192.168.0.0/24：Allow TCP connection with network address 192.168.0.0/24.

At the same time, this configuration can configure multiple rules:

listener.tcp.external.access.1 = deny 192.168.0.1
listener.tcp.external.access.2 = allow all

It means that all TCP connections except 192.168.0.1 are allowed.

listener.tcp.external.proxy_protocol

Type	Optional Value	Default
enum	`on`, `off`	-

Description

Whether the listener enables Proxy Protocol support.

If the EMQ X cluster is deployed behind HAProxy or Nginx, and you need to get the client's real source IP address and port, you need to enable this configuration.

Proxy Protcol : https://www.haproxy.com/blog/haproxy/proxy-protocol.

listener.tcp.external.proxy_protocol_timeout

Type	Default
duration	-

Description

Set the timeout for Proxy Protocol parsing. If no Proxy Protocol packet is received within this time, EMQ X Broker will close its connection.

listener.tcp.external.backlog

Type	Default
integer	1024

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

listener.tcp.external.send_timeout

Type	Default
duration	`15s`

Description

Timeout for sending TCP packets.

listener.tcp.external.send_timeout_close

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after TCP packet sending timeout.

listener.tcp.external.recbuf

Type	Default
bytesize	-

Description

TCP receiving buffer size (operating system kernel parameter)

Reference: http://erlang.org/doc/man/inet.html

listener.tcp.external.sndbuf

Type	Default
bytesize	-

Description

TCP sending buffer size (operating system kernel parameter).

Reference:http://erlang.org/doc/man/inet.html.

listener.tcp.external.buffer

Type	Default
bytesize	-

Description

TCP buffer size (user level).

This value is recommended to be greater than or equal to the maximum value of sndbuff and recbuff to avoid some performance problems. Without configuration, it equals to the maximum value of sndbuff and recbuff by default.

Reference: http://erlang.org/doc/man/inet.html.

listener.tcp.external.tune_buffer

Type	Optional Value	Default
enum	`on`, `off`	-

Description

If this configuration is enabled, please set the value equal to the maximum value of sndbuff and recbuff.

listener.tcp.external.nodelay

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the TCP_NODELAY parameter. Enabling this option allows small TCP data packets to be sent immediately.

listener.tcp.external.reuseaddr

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the SO_REUSEADDR parameter. Enabling this option allows the local port to be reused without waiting for the end of the TIME_WAIT state.

listener.tcp.internal

Type	Default
string	`127.0.0.1:11883`

Description

Configure the listening address of the MQTT / TCP listener named internal.

Example

11883: listen to 0.0.0.0: 11883 of IPv4. 127.0.0.1:11883: listening address is 11883 port on the 127.0.0.1 network card. :: 1: 11883: listen to the 11883 port on the :: 1 network card of IPv6 address.

listener.tcp.internal.acceptors

Type	Default
integer	4

Description

The size of the listener's receiving pool.

listener.tcp.internal.max_connections

Type	Default
integer	1024000

Description

The maximum number of concurrent connections allowed by the listener.

listener.tcp.internal.max_conn_rate

Type	Default
integer	1000

Description

The maximum access rate allowed by the listener. Unit: pcs / sec

listener.tcp.internal.active_n

Type	Default
integer	1000

Description

The number of times the listener continues to receive TCP packets.

listener.tcp.internal.zone

Type	Default
string	`internal`

Description

The configuration zone to which the listener belongs.

listener.tcp.internal.rate_limit

Type	Default
string	-

Description

The rate limit of the listener. The format is <limit>,<duration>.

Example

100KB,10s：Limit the number of incoming bytes within 10 seconds no tot exceed 100 KB.

listener.tcp.internal.backlog

Type	Default
integer	512

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

listener.tcp.internal.send_timeout

Type	Default
duration	`5s`

Description

Timeout for sending TCP packets.

listener.tcp.internal.send_timeout_close

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after TCP packet sending timeout.

listener.tcp.internal.recbuf

Type	Default
bytesize	`64KB`

Description

TCP receiving buffer size (operating system kernel parameter)

listener.tcp.internal.sndbuf

Type	Default
bytesize	`64KB`

Description

TCP sending buffer size (operating system kernel parameter)

listener.tcp.internal.buffer

Type	Default
bytesize	-

Description

TCP buffer size (user level).

listener.tcp.internal.tune_buffer

Type	Optional Value	Default
enum	`on`, `off`	-

Description

If this configuration is enabled, please set the value equal to the maximum value of sndbuff and recbuff.

listener.tcp.internal.nodelay

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

This is the TCP_NODELAY parameter. Enabling this option allows small TCP data packets to be sent immediately.

listener.tcp.internal.reuseaddr

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the SO_REUSEADDR parameter. Enabling this option allows the local port to be reused without waiting for the end of the TIME_WAIT state.

listener.ssl.external

Type	Default
string	`0.0.0.0:8883`

Description

Configure an SSL listener named external.

listener.ssl.external.acceptors

Type	Default
integer	16

Description

The size of the listener's receiving pool.

listener.ssl.external.max_connections

Type	Default
integer	102400

Description

The maximum number of concurrent connections allowed by the listener.

listener.ssl.external.max_conn_rate

Type	Default
integer	500

Description

The maximum access rate allowed by the listener. Unit: pcs / sec.

listener.ssl.external.active_n

Type	Default
integer	100

Description

The number of times the listener continues to receive TCP packets.

listener.ssl.external.zone

Type	Default
string	`external`

Description

The configuration group to which the listener belongs.

listener.ssl.external.access.1

Type	Default
string	`allow all`

Description

List of ACL rules of the listener. It is used to set the white/black list of the connection layer.

For example:

allow all：Allow all TCP connections. allow 192.168.0.0/24：Allow TCP connection with network address 192.168.0.0/24 to access.

At the same time, the configuration can configure multiple rules:

listener.ssl.external.access.1 = deny 192.168.0.1
listener.ssl.external.access.2 = allow all

listener.ssl.external.rate_limit

Type	Default
string	-

Description

Listener rate limit, with the format of <limit>,<duration>.

listener.ssl.external.proxy_protocol

Type	Optional Value	Default
enum	`on`, `off`	-

Description

Whether the listener enables Proxy Protocol support.

If the EMQ X cluster is deployed behind HAProxy or Nginx, and it is required to get the client's real source IP address and port, you need to enable this configuration.

Proxy Protcol reference: https://www.haproxy.com/blog/haproxy/proxy-protocol.

listener.ssl.external.proxy_protocol_timeout

Type	Default
duration	-

Description

Set the timeout for Proxy Protocol parsing. If no Proxy Protocol packet is received within this time, EMQ X Broker will close its connection.

listener.ssl.external.tls_versions

Type	Default
string	`tlsv1.2,tlsv1.1,tlsv1`

Description

Specify the SSL version list supported by the server. For details, see http://erlang.org/doc/man/ssl.html.

listener.ssl.external.handshake_timeout

Type	Default
duration	`15s`

Description

Specify the timeout period for the SSL handshake process.

listener.ssl.external.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

Specify SSL private key file (PEM).

listener.ssl.external.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

Specify SSL certificate file(PEM).

listener.ssl.external.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

Specify the CA certificate file for SSL (PEM).

listener.ssl.external.dhfile

Type	Default
string	`etc/certs/dh-params.pem`

Description

If using the Ephemeral Diffie-Hellman algorithm, specify the key file used by the algorithm.

listener.ssl.external.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

Specifies whether to verify the client during the handshake.

listener.ssl.external.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

If the client does not have a certificate during the SSL handshake, it determines whether to let the handshake fail.

listener.ssl.external.ciphers

Type Default

string ECDHE-ECDSA-AES256-GCM-SHA384,ECDHE-RSA-AES256-GCM-SHA384,ECDHE-ECDSA-AES256-SHA384,ECDHE-RSA-AES256-SHA384,ECDHE-ECDSA-DES-CBC3-SHA,ECDH-ECDSA-AES256-GCM-SHA384,ECDH-RSA-AES256-GCM-SHA384,ECDH-ECDSA-AES256-SHA384,ECDH-RSA-AES256-SHA384,DHE-DSS-AES256-GCM-SHA384,DHE-DSS-AES256-SHA256,AES256-GCM-SHA384,AES256-SHA256,ECDHE-ECDSA-AES128-GCM-SHA256,ECDHE-RSA-AES128-GCM-SHA256,ECDHE-ECDSA-AES128-SHA256,ECDHE-RSA-AES128-SHA256,ECDH-ECDSA-AES128-GCM-SHA256,ECDH-RSA-AES128-GCM-SHA256,ECDH-ECDSA-AES128-SHA256,ECDH-RSA-AES128-SHA256,DHE-DSS-AES128-GCM-SHA256,DHE-DSS-AES128-SHA256,AES128-GCM-SHA256,AES128-SHA256,ECDHE-ECDSA-AES256-SHA,ECDHE-RSA-AES256-SHA,DHE-DSS-AES256-SHA,ECDH-ECDSA-AES256-SHA,ECDH-RSA-AES256-SHA,AES256-SHA,ECDHE-ECDSA-AES128-SHA,ECDHE-RSA-AES128-SHA,DHE-DSS-AES128-SHA,ECDH-ECDSA-AES128-SHA,ECDH-RSA-AES128-SHA,AES128-SHA

Description

Specify the cipher suite supported by the server.

listener.ssl.external.psk_ciphers

Type	Default
string	`PSK-AES128-CBC-SHA,PSK-AES256-CBC-SHA,PSK-3DES-EDE-CBC-SHA,PSK-RC4-SHA`

Description

If using the PSK algorithm, specify the PSK Cipher list supported by the server. Note that only one of 'listener.ssl.external.ciphers' and 'listener.ssl.external.psk_ciphers' can be configured.

listener.ssl.external.secure_renegotiate

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Specifies whether to reject renegotiation requests if the client does not follow RFC 5746

listener.ssl.external.reuse_sessions

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Specify whether to support SSL session reuse. For details, seehttp://erlang.org/doc/man/ssl.html.

listener.ssl.external.honor_cipher_order

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Specify whether to use the server's preferences to select Ciphers.

listener.ssl.external.peer_cert_as_username

Type	Optional Value	Default
enum	`cn`, `dn`, `crt`	`cn`

Description

Use the value of the CN, DN, or CRT field in the client certificate as the value of the Username field in the MQTT CONNECT packet. Note that listener.ssl.external.verify should be set to verify_peer.

listener.ssl.external.backlog

Type	Default
integer	1024

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

listener.ssl.external.send_timeout

Type	Default
duration	`15s`

Description

Timeout for sending TCP packets.

listener.ssl.external.send_timeout_close*

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after TCP packet sending timeout.

listener.ssl.external.recbuf

Type	Default
bytesize	-

Description

TCP receiving buffer size (operating system kernel level parameter).

Reference:http://erlang.org/doc/man/inet.html.

listener.ssl.external.sndbuf

Type	Default
bytesize	-

Description

TCP sending buffer size (operating system kernel level parameter).

Reference:http://erlang.org/doc/man/inet.html.

listener.ssl.external.buffer

Type	Default
bytesize	-

Description

CP buffer size (user level).

Reference:http://erlang.org/doc/man/inet.html.

listener.ssl.external.tune_buffer

Type	Optional Value	Default
enum	`on`, `off`	-

Description

If this configuration is enabled, please set the value equal to the maximum value of sndbuff and recbuff.

listener.ssl.external.nodelay

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the TCP_NODELAY parameter. Enabling this option means that the Nagle algorithm is disabled and small packets will be sent immediately.

listener.ssl.external.reuseaddr

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the SO_REUSEADDR parameter. Enabling this option allows the local port to be reused without waiting for the end of the TIME_WAIT state.

listener.ws.external

Type	Default
string	`8083`

Description

Configure the listening address of the MQTT/WS listener named external.

Example

8083: Listen s to 0.0.0.0: 8083 of IPv4. 127.0.0.1:8083: Listening address is 8083 port on the 127.0.0.1 network card. :: 1: 8083: Listen to the 8083 port on the network card :: 1 of IPv6 address.

listener.ws.external.mqtt_path

Type	Default
string	`/mqtt`

Description

WebSocket's MQTT protocol path. So the address of EMQ X Broker's WebSocket is: ws://<ip>:<port>/mqtt.

listener.ws.external.acceptors

Type	Default
integer	4

Description

The size of the listener's receiving pool.

listener.ws.external.max_connections

Type	Default
integer	102400

Description

The maximum number of concurrent connections allowed by the listener.

listener.ws.external.max_conn_rate

Type	Default
integer	1000

Description

The maximum access rate allowed by the listener. Unit: pcs/sec

listener.ws.external.active_n

Type	Default
integer	100

Description

The number of times the listener continues to receive TCP packets.

listener.ws.external.rate_limit

Type	Default
string	`100KB,10s`

Description

The rate limit of the listener. The format is <limit>,<duration>.

Example

100KB,10s： Limit the number of incoming bytes within 10 seconds to not exceed 100 KB.

listener.ws.external.zone

Type	Default
string	`external`

Description

The configuration zone to which the listener belongs.

listener.ws.external.access.1

Type	Default
string	`allow all`

Description

List of ACL rules of the listener. It is used to set the white/black list of the connection layer.

listener.ws.external.verify_protocol_header

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to verify that the HTTP header carried by WebSocket is correct. WeChat applet needs to disable this verification.

listener.ws.external.proxy_address_header

Type	Optional Value	Default
string	`X-Forwarded-For`	-

Description

If the EMQ X cluster is deployed behind HAProxy or Nginx, you can open the configuration to obtain the real IP address of the client.

listener.ws.external.proxy_port_header

Type	Optional Value	Default
string	`X-Forwarded-Port`	-

Description

If the EMQ X cluster is deployed behind HAProxy or Nginx, you can open the configuration to get the real port of the client.

listener.ws.external.proxy_protocol

Type	Optional Value	Default
enum	`on`, `off`	-

Description

Whether the listener enables Proxy Protocol support.

If the EMQ X cluster is deployed behind HAProxy or Nginx, and you need to get the client's real source IP address and port, you need to open this configuration.

Proxy Protcol reference: https://www.haproxy.com/blog/haproxy/proxy-protocol.

listener.ws.external.proxy_protocol_timeout

Type	Default
duration	-

Description

Set the timeout for Proxy Protocol parsing. If no Proxy Protocol packet is received within this time, EMQ X Broker will close its connection.

listener.ws.external.backlog

Type	Default
integer	1024

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

listener.ws.external.send_timeout

Type	Default
duration	`15s`

Description

Timeout for sending TCP packets.

listener.ws.external.send_timeout_close

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after TCP packet sending timeout.

listener.ws.external.recbuf

Type	Default
bytesize	-

Description

TCP receiving buffer size (operating system kernel level parameter)

listener.ws.external.sndbuf

Type	Default
bytesize	-

Description

TCP sending buffer size (operating system kernel level parameter)

listener.ws.external.buffer

Type	Default
bytesize	-

Description

TCP buffer size (user level).

listener.ws.external.tune_buffer

Type	Optional Value	Default
enum	`on`, `off`	-

Description

If this configuration is enabled, please set the value equal to the maximum value of sndbuff and recbuff.

listener.ws.external.nodelay

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the TCP_NODELAY parameter. Enabling this option allows small TCP data packets to be sent immediately.

listener.ws.external.compress

Type	Optional Value	Default
enum	`true`, `false`	-

Description

Whether to compress WebSocket messages. The implementation of compression depends on zlib.

The configuration items under defalte_opts belong to the compression-related parameter configuration, if not necessary, please do not modify it.

listener.ws.external.deflate_opts.level

Type	Optional Value	Default
enum	`none`, `default`, `best_compression`, `best_speed`	-

Description

compression level

listener.ws.external.deflate_opts.mem_level

Type	Optional Value	Default
integer	1 - 9	-

Description

Compression parameters. It means memory usage limit level, and configure how much memory can be opened to participate in the compression process.

1: The least memory, but will reduce the compression rate. 9: The most memory, and will increase the calculation speed and compression rate.

If not configured, the default is 8.

listener.ws.external.deflate_opts.strategy

Type	Optional Value	Default
enum	`default`, `filtered`, `huffman_only`, `rle`	-

Description

Compression strategy for tuning compression ratio:

default: for ordinary data.
filtered: data generated by filters or predictors, suitable for content with strong randomness.
huffman_only: Mandatory use of Huffman algorithm. Better than filtered.
rle: limit the matching distance to 1 (Run-Lenght Encoding), faster than huffman_only, but mainly used for PNG images.

These strategies only affect the compression ratio and will not have any impact on correctness.

listener.ws.external.deflate_opts.server_context_takeover

Type	Optional Value	Default
enum	`takeover`, `no_takeover`	-

Description

Whether to allow the server's compression context to be passed between frames.

listener.ws.external.deflate_opts.client_context_takeover

Type	Optional Value	Default
enum	`takeover`, `no_takeover`	-

Description

Whether to allow the client's compression context to be passed between frames.

listener.ws.external.deflate_opts.server_max_window_bits

Type	Optional Value	Default
integer	8 - 15	-

Description

Maximum window value on the server side. Setting a larger value will result in better compression ratio, but will consume additional memory.

listener.ws.external.deflate_opts.client_max_window_bits

Type	Optional Value	Default
integer	8 - 15	-

Description

Client maximum window value. Setting a larger value will result in better compression ratio, but will consume additional memory.

listener.ws.external.idle_timeout

Type	Default
duration	-

Description

The daze time after the TCP connection is established. If no packets are received within this time, the connection will be closed.

listener.ws.external.max_frame_size

Type	Default
integer	-

Description

The maximum allowed length of a single MQTT packet.

listener.wss.external

Type	Default
string	`0.0.0.0:8084`

Description

Configure a WSS (MQTT/WebSocket/SSL) listener named external.

listener.wss.external.mqtt_path

Type	Default
string	`/mqtt`

Description

WebSocket URL Path.

listener.wss.external.acceptors

Type	Default
integer	4

Description

The size of the listener's receiving pool.

listener.wss.external.max_connections

Type	Default
integer	16

Description

The maximum number of concurrent connections allowed by the listener.

listener.wss.external.max_conn_rate

Type	Default
integer	1000

Description

The maximum access rate allowed by the listener. Unit: pcs/sec.

listener.wss.external.active_n

Type	Default
integer	100

Description

The number of times the listener continues to receive TCP packets.

listener.wss.external.rate_limit

Type	Default
string	-

Description

The rate limit of the listener. The format is <limit>,<duration>.

listener.wss.external.zone

Type	Default
string	`external`

Description

The configuration group to which the listener belongs.

listener.wss.external.access.1

Type	Default
string	`allow all`

Description

List of ACL rules of the listener. It is used to set the white/black list of the connection layer.

E.g:

allow all: Allow all TCP connections. allow 192.168.0.0/24: Allow TCP connections with a network address of 192.168.0.0 / 24 to access.

At the same time, the configuration can configure multiple rules:

listener.wss.external.access.1 = deny 192.168.0.1
listener.wss.external.access.2 = allow all

listener.wss.external.verify_protocol_header

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to verify that the HTTP header carried by WebSocket is correct. WeChat applet needs to disable this verification.

listener.wss.external.proxy_address_header

Type	Default
string	`X-Forwarded-For`

Description

If the EMQ X cluster is deployed in HAProxy or Nginx, you can open the configuration to obtain the real IP address of the client.

listener.wss.external.proxy_protocol

Type	Optional Value	Default
enum	`on`, `off`	-

Description

Whether the listener enables Proxy Protocol support.

If the EMQ X cluster is deployed behind HAProxy or Nginx, and you need to get the client's real source IP address and port, you need to open this configuration.

Proxy Protcol reference:https://www.haproxy.com/blog/haproxy/proxy-protocol.

listener.wss.external.proxy_protocol_timeout

Type	Default
duration	-

Description

Set the timeout for Proxy Protocol parsing. If no Proxy Protocol packet is received within this time, EMQ X Broker will close its connection.

listener.wss.external.tls_versions

Type	Default
string	`tlsv1.2,tlsv1.1,tlsv1`

Description

Specify the SSL version list supported by the server. For details, see http://erlang.org/doc/man/ssl.html.

listener.wss.external.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

Specify SSL private key file (PEM).

listener.wss.external.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

Specify SSL certificate file(PEM).

listener.wss.external.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

If using SSL, specify the CA certificate file for SSL (PEM).

listener.wss.external.dhfile

Type	Default
string	`etc/certs/dh-params.pem`

Description

If using the Ephemeral Diffie-Hellman algorithm, specify the key file used by the algorithm.

listener.wss.external.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

Specifies whether to verify the client during the handshake.

listener.wss.external.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

If the client does not have a certificate during the SSL handshake, it determines whether to let the handshake fail.

listener.wss.external.ciphers

Type Default

Description

Specifies the cipher suite supported by the server.

listener.wss.external.psk_ciphers

Type	Default
string	`PSK-AES128-CBC-SHA,PSK-AES256-CBC-SHA,PSK-3DES-EDE-CBC-SHA,PSK-RC4-SHA`

Description

If using the PSK algorithm, specify the PSK Cipher list supported by the server. Note that only one of 'listener.wss.external.ciphers' and 'listener.wss.external.psk_ciphers' can be configured.

listener.wss.external.secure_renegotiate

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Specifies whether to reject renegotiation requests if the client does not follow RFC 5746

listener.wss.external.reuse_sessions

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Specifies whether to support SSL session reuse. For details, see http://erlang.org/doc/man/ssl.html.

listener.wss.external.honor_cipher_order

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Specify whether to use the server's preferences to select Ciphers.

listener.wss.external.peer_cert_as_username

Type	Optional Value	Default
enum	`cn`, `dn`, `crt`	`cn`

Description

Use the value of the CN, DN, or CRT field in the client certificate as the value of the Username field in the MQTT CONNECT packet. Note that listener.wss.external.verify should be set to verify_peer.

listener.wss.external.backlog

Type	Default
integer	1024

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

listener.wss.external.send_timeout

Type	Default
duration	`15s`

Description

Timeout for sending TCP packets.

listener.wss.external.send_timeout_close*

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after TCP packet sending timeout.

listener.wss.external.recbuf

Type	Default
bytesize	-

Description

TCP receiving buffer size (operating system kernel level parameter)

Reference:http://erlang.org/doc/man/inet.html

listener.wss.external.sndbuf

Type	Default
bytesize	-

Description

TCP sending buffer size (operating system kernel level parameter)

Reference:http://erlang.org/doc/man/inet.html

listener.wss.external.buffer

Type	Default
bytesize	-

Description

TCP buffer size (user level).

Reference:http://erlang.org/doc/man/inet.html

listener.wss.external.tune_buffer

Type	Optional Value	Default
enum	`on`, `off`	-

Description

If you open this configuration, please set the value equal to the maximum value of sndbuff and recbuff.

listener.wss.external.nodelay

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

This is the TCP_NODELAY parameter. Enabling this option allows small TCP data packets to be sent immediately.

listener.wss.external.compress

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

If this option is set to true, Websocket messages will be compressed.

listener.wss.external.deflate_opts.level

Type	Optional Value	Default
enum	`none`, `default`, `best_compression`, `best_speed`	`default`

Description

Compression level.

listener.wss.external.deflate_opts.mem_level

Type	Optional Value	Default
integer	1 - 9	-

Description

Compression parameters. It means memory usage limit level, configures how much memory can be opened to participate in the compression process.

1: The least memory, but will reduce the compression rate. 9: The most memory, and will increase the calculation speed and compression rate.

If not configured, the default is 8.

listener.wss.external.deflate_opts.strategy

Type	Optional Value	Default
enum	`default`, `filtered`, `huffman_only`, `rle`	-

Description

Compression strategy for tuning compression ratio:

default: for ordinary data.
filtered: data generated by filters or predictors, suitable for content with strong randomness.
huffman_only: Mandatory use of Huffman algorithm. Better than filtered.
rle: limit the matching distance to 1 (Run-Lenght Encoding), faster than huffman_only, but mainly used for PNG images.

These strategies only affect the compression ratio and will not have any impact on correctness.

listener.wss.external.deflate_opts.server_context_takeover

Type	Optional Value	Default
enum	`takeover`, `no_takeover`	-

Description

Whether to allow the server's compression context to be passed between frames.

listener.wss.external.deflate_opts.client_context_takeover

Type	Optional Value	Default
enum	`takeover`, `no_takeover`	-

Description

Whether to allow the client's compression context to be passed between frames.

listener.wss.external.deflate_opts.server_max_window_bits

Type	Optional Value	Default
integer	8 - 15	-

Description

Maximum window value on the server side. Setting a larger value will result in better compression ratio, but will consume additional memory.

listener.wss.external.deflate_opts.client_max_window_bits

Type	Optional Value	Default
integer	8 - 15	-

Description

Client maximum window value. Setting a larger value will result in better compression ratio, but will consume additional memory.

listener.wss.external.idle_timeout

Type	Default
duration	-

Description

The daze time after the TCP connection is established. If no packets are received within this time, the connection will be closed.

listener.wss.external.max_frame_size

Type	Default
integer	-

Description

The maximum length of a single MQTT packet.

plugins.etc_dir

Type	Default
string	`etc/plugins`

Description

The configuration directory of the plugin.

plugins.loaded_file

Type	Default
string	`etc/loaded_plugins`

Description

The configuration file path of the plugin startup list.

plugins.expand_plugins_dir

Type	Default
string	`plugins/`

Description

External plugin storage directory.

broker.sys_interval

Type	Default
duration	`1m`

Description

Set the system topic ($SYS) message release interval.

broker.sys_heartbeat

Type	Default
duration	`30s`

Description

Set the system heartbeat message release interval. The system heartbeat message includes the following two topics:

"$SYS/brokers/<node>/uptime"
"$SYS/brokers/<node>/datetime"

broker.enable_session_registry

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Enable or disable global session registration.

broker.session_locking_strategy

Type	Optional Value	Default
enum	`local`, `one`, `quorum`, `all`	`quorum`

Description

Set the type of session cluster lock. The session cluster lock is used to prevent the same client from creating multiple sessions on multiple different nodes, which is common when clients frequently switch between nodes for logging.

broker.shared_subscription_strategy

Type	Optional Value	Default
enum	`random`, `round_robin`, `sticky`, `hash`	`random`

Description

Set a distribution strategy for shared subscriptions. Optional values are:

random: Choose randomly among all subscribers
round_robin: According to the order of subscription
sticky: Always sent to the last selected subscriber
hash: According to the hash value of the publisher ClientID

broker.shared_dispatch_ack_enabled

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Enable or disable the ACK check function for qos1/qos2 messages in shared subscriptions. After enabling, if it is delivered to a subscriber but fails to receive the ACK, it will try to deliver to the next subscriber in the subscription group.

broker.route_batch_clean

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Enable or disable batch cleanup routing information. Batch cleanup routing can be used in a short period of time when a large number of clients go offline to improve cleanup efficiency.

sysmon.long_gc

Type	Default
duration	`0ms`

Description

Enable garbage collection time monitoring and trigger an alarm when the collection time exceeds the set value, 0 means disabling this monitoring.

sysmon.long_schedule

Type	Default
duration	`240ms`

Description

Enable process scheduling time monitoring and trigger an alarm when the scheduling time exceeds the set value, 0 means disabling this monitoring.

sysmon.large_heap

Type	Default
bytesize	`8MB`

Description

Enable stack size monitoring and trigger an alarm when the stack size is still greater than the set value after the process performs garbage collection. 0 means disabling this monitoring.

sysmon.busy_port

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Specifies whether to enable inter-process message channel busy monitoring.

sysmon.busy_dist_port

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Specifies whether to enable cluster RPC channel busy monitoring.

os_mon.cpu_check_interval

Type	Default
duration	`60s`

Description

CPU usage rate check cycle.

os_mon.cpu_high_watermark

Type	Default
percent	`80%`

Description

An alarm will be triggered when the CPU usage exceeds os_mon.cpu_high_watermark.

os_mon.cpu_low_watermark

Type	Default
percent	`60%`

Description

The alarm will be cleared when the CPU usage drops back below os_mon.cpu_low_watermark .

os_mon.mem_check_interval

Type	Default
duration	`60s`

Description

Memory usage check cycle.

os_mon.sysmem_high_watermark

Type	Default
percent	`70%`

Description

When the memory allocated by EMQ X Broker for all processes as a percentage of system memory exceeds os_mon.procmem_high_watermark, an alarm will be triggered.

os_mon.procmem_high_watermark

Type	Default
percent	`5%`

Description

When the memory allocated by EMQ X Broker for a single process as a percentage of system memory exceeds os_mon.procmem_high_watermark, an alarm will be triggered.

vm_mon.check_interval

Type	Default
duration	`30s`

Description

Check interval for process number.

vm_mon.process_high_watermark

Type	Default
percent	`80%`

Description

When the current process number as a percentage of the maximum process number exceeds vm_mon.process_high_watermark, an alarm will be triggered. The maximum process number is determined by the node.process_limit configuration item.

vm_mon.process_low_watermark

Type	Default
percent	`60%`

Description

When the percentage of the current number of processes in the maximum number of processes falls below vm_mon.process_low_watermark, an alarm will be triggered. The maximum number of processes is determined by the node.process_limit configuration item.

emqx-auth-clientid

`auth.client.<Number>.clientid` & `auth.client.<Number>.password`

Type	Default
string	-

Description

The authentication data of the client, where auth.client.<Number>.password is the clear text password. auth.client.<Number>.clientid and auth.client.<Number>.password for the same <Number> must appear in pairs. <Number> is an integer number used to distinguish authentication data of multiple clients.

auth.client.password_hash

Type	Optional Value	Default
enum	`plain`, `md5`, `sha`, `sha256`	`sha256`

Description

Hash algorithm is used when the password is stored in the database. The following options are available:

plain

The password is stored in clear text.

md5

The password is encrypted and stored using the MD5 algorithm.

sha

The password is encrypted and stored using the SHA-1 algorithm.

sha256

The password is encrypted and stored using the SHA-256 algorithm.

emqx-auth-http

auth.http.auth_req

Type	Default
string	`http://127.0.0.1:8991/mqtt/auth`

Description

Specify the target URL of the authentication request.

auth.http.auth_req.method

Type	Optional Value	Default
enum	`get`, `post`	`post`

Description

Specify the request method of the authentication request.

auth.http.auth_req.params

Type	Format	Default
string	`K=v` key-value pairs separated by`,` , `v` can be fixed content or placeholder	`clientid=%c,username=%u,password=%P`

Description

Specify the data carried in the authentication request. When using the GET method, the value of auth.http.auth_req.params will be converted into k=v key-value pairs separated by & and sent as query string parameters. When using the POST method, the value of auth.http.auth_req.params will be converted into k=v key-value pairs separated by & and sent in the form of Request Body. All placeholders will be replaced by run-time data , and the available placeholders are as follows:

Placeholder	Replace content
`%u`	Username
`%c`	MQTT Client ID
`%a`	Client's network IP address
`%r`	The protocol used by the client can be:`mqtt`, `mqtt-sn`, `coap`, `lwm2m` and `stomp`
`%P`	Password
`%p`	Server port for client connection
`%c`	Common Name in client certificate
`%d`	Subject in client certificate

auth.http.super_req

Type	Default
string	`http://127.0.0.1:8991/mqtt/superuser`

Description

Specify the target URL for the superuser authentication request.

auth.http.super_req.method

Type	Optional Value	Default
enum	`get`, `post`	`post`

Description

Specifies the request method of the super user authentication request.

auth.http.super_req.params

Type	Format	Default
string	`K=v` key-value pairs separated by`,` , `v` can be fixed content or placeholder	`clientid=%c,username=%u`

Description

auth.http.acl_req

Type	Default
string	`http://127.0.0.1:8991/mqtt/acl`

Description

Specify the target URL for ACL verification requests.

auth.http.acl_req.method

Type	Optional Value	Default
enum	`get`, `post`	`post`

Description

Specifies the request method for ACL verification requests.

auth.http.acl_req.params

Type	Format	Default
string	`K=v` key-value pairs separated by`,` , `v` can be fixed content or placeholder	`access=%A,username=%u,clientid=%c,ipaddr=%a,topic=%t,mountpoint=%m`

Description

Placeholder	Replace content
`%A`	Permission to be verified, 1 means subscription, 2 means publish
`%u`	MQTT Client ID
`%c`	Client identifier
`%a`	Client network IP address
`%r`	The protocol used by the client can be: `mqtt`, `mqtt-sn`, `coap`, `lwm2m` and `stomp`
`%m`	Mount point
`%t`	Topic

auth.http.request.timeout

Type	Default
duration	`0s`

Description

HTTP request timeout. Any setting equivalent to 0s means never timeout.

auth.http.request.connect_timeout

Type	Default
duration	`0s`

Description

Connection timeout for HTTP requests. Any setting value equivalent to 0s means never time out.

auth.http.request.retry_times

Type	Default
integer	3

Description

The number of retries when an HTTP request fails.

auth.http.request.retry_interval

Type	Default
duration	`1s`

Description

Retry interval when HTTP request fails.

auth.http.request.retry_backoff

Type	Default
float	2.0

Description

When the HTTP request fails, the retry interval uses the exponential backoff algorithm. This configuration item is used to specify the backoff coefficient of the exponential backoff algorithm.

auth.http.header.<Key>

Type	Default
string	-

Description

Specify the data in the HTTP request header. <Key> Specify the field name in the HTTP request header, and the value of this configuration item is the corresponding field value. <Key> can be the standard HTTP request header field. User can also customize the field to configure multiple different request header fields.

Example

auth.http.header.Accept = */*
auth.http.header.Accept-Encoding = *

auth.http.ssl.cacertfile

Type	Default
string	`etc/certs/ca.pem`

Description

CA certificate file path.

auth.http.ssl.certfile

Type	Default
string	`etc/certs/client-cert.pem`

Description

Client certificate file path.

auth.http.ssl.keyfile

Type	Default
string	`etc/certs/client.key.pem`

Description

Client private key file path.

emqx-auth-jwt

auth.jwt.secret

Type	Default
string	`emqxsecret`

Description

Set HMAC Secret.

auth.jwt.from

Type	Optional Value	Default
enum	`username`, `password`	`password`

Description

Where to get JWT. Optional values are

username: The username field of the MQTT CONNECT packet is used as JWT.
password: The password field of the MQTT CONNECT packet is used as JWT.

auth.jwt.pubkey

Type	Default
string	`etc/certs/jwt_public_key.pem`

Description

If you use RSA or ECDSA encryption algorithm, you must specify the private key file.

auth.jwt.verify_claims

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Enable or disable Claims verification.

auth.jwt.verify_claims.<claims>

Type	Default
string	-

Description

When the Claims verification function is enabled, you can set optional values for fields in the JWT.

For example, if the value of sub in the Claim in JWT is expected to be" abc ", the following rules can be configured:

auth.jwt.verify_claims.sub = abc

The expected value supports two wildcards:

%u: username
%c: clientid

For example, if the value of the sub field in the JWT is expected to be the same as the username field in the MQTT CONNECT message, the following rules can be configured:

auth.jwt.verify_claims.sub = %u

emqx-auth-ldap

auth.ldap.servers

Type	Default
string	`127.0.0.1`

Description

LDAP service address.

auth.ldap.port

Type	Default
integer	389

Description

LDAP service port.

auth.ldap.pool

Type	Optional Value	Default
integer	> 0	8

Description

Connection pool size.

auth.ldap.bind_dn

Type	Default
string	`cn=root,dc=emqx,dc=io`

Description

The DN for logging into the LDAP service.

auth.ldap.bind_password

Type	Default
string	`public`

Description

The password for logging into the LDAP service.

auth.ldap.timeout

Type	Default
duration	`30s`

Description

The query timeout.

auth.ldap.device_dn

Type	Default
string	`ou=device,dc=emqx,dc=io`

Description

The DN to which the client belongs.

auth.ldap.match_objectclass

Type	Default
string	`mqttUser`

Description

The name of the client object.

auth.ldap.username.attributetype

Type	Default
string	`uid`

Description

The data type of the Username attribute.

auth.ldap.password.attributetype

Type	Default
string	`userPassword`

Description

The data type of the Password attribute.

auth.ldap.ssl

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to enable SSL.

auth.ldap.ssl.certfile

Type	Default
string	-

Description

SSL server certificate path.

auth.ldap.ssl.keyfile

Type	Default
string	-

Description

SSL server key file path.

auth.ldap.ssl.cacertfile

Type	Default
string	-

Description

CA certificate file path.

auth.ldap.ssl.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	-

Description

SSL authentication method:

verify_none：One-way authentication.
verify_peer：Two-way authentication.

auth.ldap.ssl.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

If the client does not provide an SSL certificate, disconnect it.

emqx-auth-mongo

auth.mongo.type

Type	Optional Value	Default
enum	`single`, `unknown`, `sharded`, `rs`	`single`

Description

Set the topology type of MongoDB:

single: single node
unknown: unknown
sharded: sharding mode
rs: replicated set

auth.mongo.rs_set_name

Type	Default
string	-

Description

In the case of using rs mode, set the name of rs.

auth.mongo.rs_set_name

Type	Default
string	`127.0.0.1:27017`

Description

Set the address of MongoDB service. If there are multiple items, use comma , to separate them.

auth.mongo.pool

Type	Default
integer	8

Description

Set the number of processes in the MongoDB connection pool.

Type	Default
string	-

Description

Set the MongoDB's username.

auth.mongo.password

Type	Default
string	-

Description

Set the MongoDB's password.

auth.mongo.auth_source

Type	Default
string	`mqtt`

Description

Set the MongoDB authentication source database name.

auth.mongo.database

Type	Default
string	`mqtt`

Description

Set MongoDB database name.

auth.mongo.query_timeout

Type	Default
duration	`5s`

Description

Set the timeout for accessing MongoDB.

auth.mongo.ssl

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Set whether to use SSL to access MongoDB.

auth.mongo.ssl_opts.keyfile

Type	Default
string	-

Description

If using SSL to access MongoDB, set the private key file of the SSL client.

auth.mongo.ssl_opts.certfile

Type	Default
string	-

Description

If using SSL to access MongoDB, set the SSL client certificate file.

auth.mongo.ssl_opts.cacertfile

Type	Default
string	-

Description

If you use SSL to access MongoDB, set the SSL certificate file.

auth.mongo.w_mode

Type	Optional Value	Default
enum	`unsafe`, `safe`, `undef`	`undef`

Description

Set the write mode of MongoDB.

auth.mongo.r_mode

Type	Optional Value	Default
enum	`master`, `slave_ok`, `undef`	`undef`

Description

Set the read mode of MongoDB.

auth.mongo.auth_query.collection

Type	Default
string	`mqtt_user`

Description

Collection name used in the authentication process.

auth.mongo.auth_query.password_field

Type	Default
string	`password`

Description

The main fields used in the authentication process. To add salt after the password, it can be configured as:

auth.mongo.auth_query.password_field = password,salt

auth.mongo.auth_query.password_hash

Type	Optional Value	Default
enum	`plain`, `md5`, `sha`, `sha256`, `bcrypt`	`sha256`

Description

Set the hash algorithm used for the password field. To add salt after the sha256 password, you can set it to:

auth.mongo.auth_query.password_hash = sha256,salt

To add salt before the sha256 password, you can set it to:

auth.mongo.auth_query.password_hash = salt,sha256

To add salt before the bcrypt password, you can set it to:

auth.mongo.auth_query.password_hash = salt,bcrypt

auth.mongo.auth_query.selector

Type	Default
string	`username=%u`

Description

MongoDB statements are executed during the authentication process. Commands can support following wildcards:

%u: username
%c: clientid
%C: Common Name in client TLS certificate
%d: Subject in the client's TLS certificate

auth.mongo.auth_query.super_query

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to use SuperUser in authentication.

auth.mongo.super_query.collection

Type	Default
string	`mqtt_user`

Description

If using SuperUser, specify the MongoDB Collection of SuperUser.

auth.mongo.super_query.selector

Type	Default
string	`username=%u, clientid=%c`

Description

If SuperUser is used, specify the MongoDB statement used to query SuperUser.

auth.mongo.acl_query

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to enable the ACL function.

auth.mongo.acl_query.collection

Type	Default
string	`mqtt_acl`

Description

If using the ACL function, specify the MongoDB Collection that queries the ACL rules.

auth.mongo.acl_query.selector

Type	Default
string	`username=%u`

Description

If the ACL function is used, specify the MongoDB statement used to query the ACL rules. It can support multiple ACL statements, and "or" is used to connect multiple statements.

For example, configure the following two access rules:

auth.mongo.acl_query.selector.1 = username=%u
auth.mongo.acl_query.selector.2 = username=$all

And the username of the client equals 'ilyas'. When querying acl rules, the following MongoDB statement will be executed:

db.mqtt_acl.find({$or: [{username: "ilyas"},  {username: "$all"}]});

auth.mongo.topology.pool_size

Type	Default
integer	1

Description

MongoDB topology parameters, that set the thread pool size.

auth.mongo.topology.max_overflow

Type	Default
integer	0

Description

MongoDB topology parameter, which determines how many additional worker threads are allowed to be created when all workers in the thread pool are busy.

auth.mongo.topology.overflow_ttl

Type	Default
integer	1000

Description

MongoDB topology parameter, which determines how long to release additional worker threads when a worker is idle. Unit: ms

auth.mongo.topology.overflow_check_period

Type	Default
integer	1000

Description

MongoDB topology parameters, which determines how often to check for idle threads to release additional workers.

auth.mongo.topology.local_threshold_ms

Type	Default
integer	1000

Description

MongoDB topology parameters, which is to select the strategy of the secondary node used to process user requests. The minimum value of the RTT of all nodes is LowestRTT, then only those secondary nodes with RTT <LowestRTT + local_threshold_ms will be selected.

auth.mongo.topology.connect_timeout_ms

Type	Default
integer	20000

Description

MongoDB topology parameter, means MongoDB connection timeout, unit: ms.

auth.mongo.topology.socket_timeout_ms

Type	Default
integer	100

Description

MongoDB topology parameter, that means MongoDB message sending timeout period, unit: ms.

auth.mongo.topology.server_selection_timeout_ms

Type	Default
integer	30000

Description

MongoDB topology parameter, select the timeout period of MongoDB Server, unit: ms.

auth.mongo.topology.wait_queue_timeout_ms

Type	Default
integer	1000

Description

MongoDB topology parameters, that selects the worker's waiting timeout period from the thread pool, unit: ms.

auth.mongo.topology.heartbeat_frequency_ms

Type	Default
integer	10000

Description

MongoDB topology parameters, the interval between topological scans, unit: ms.

auth.mongo.topology.min_heartbeat_frequency_ms

Type	Default
integer	1000

Description

MongoDB topology parameter, the minimum allowed value of heartbeat_frequency_ms, unit: milliseconds.

emqx-auth-mysql

auth.mysql.server

Type	Default
ip	`127.0.0.1:3306`

Description

MySQL server address.

auth.mysql.pool

Type	Default
integer	8

Description

Database connection thread pool size.

auth.mysql.username

Type	Default
string	-

Description

MySQL username.

auth.mysql.password

Type	Default
string	-

Description

MySQL password.

auth.mysql.database

Type	Default
string	`mqtt`

Description

MySQL database name.

auth.mysql.query_timeout

Type	Default
duration	`5s`

Description

MySQL data query timeout. The query timeout means user data was not found.

< >

auth.mysql.auth_query

Type	Default
string	`select password from mqtt_user where username = '%u' limit 1`

Description

The MySQL select statement used during authentication, the selected data will be compared with the password encrypted by the encryption method specified by auth.mysql.password_hash, and the client with the same content after the comparison will be allowed to log in. The stored password with salt needs to select the fields corresponding to the salt at the same time, such as select password, salt from mqtt_user where username = '%u' limit 1. Password and salt field names cannot be modified, the table name and the field name in the WHERE clause can change depending on the situation. The WHERE clause supports the following placeholders:

Placeholder	Description
`%u`	username specified in the CONNECT packet by the MQTT client that will be replaced
`%c`	ClientID specified in the CONNECT packet by the MQTT client that will be replaced
`%C`	Common Name in the client certificate when TLS that will be replaced is connected
`%d`	Subject in the client certificate when TLS that will be replaced is connected

auth.mysql.password_hash

Type	Default
string	`sh256`

Description

The encryption method used for the password stored in the database. The following encryption methods are supported:

plain, both forward and backward salting is supported, such as salt, plain
md5, both forward and backward salting is supported
sha, both forward and backward salting is supported
sha256, both forward and backward salting is supported
sha512, both forward and backward salting is supported
pbkdf2, the format is pbkdf2,<Hashfun>,<Iterations>,<Dklen>. Among them, <Hashfun> is the hash function used, which supports md4, md5, ripemd160 sha, sha224, sha256, sha384, sha512. <Iterations>is the number of iterations and <Dklen>is the length of the derived key. Example: pbkdf2, sha256,1000,20
bcrypt, only forward salting is supported, eg salt, bcrypt

auth.mysql.super_query

Type	Default
string	`select is_superuser from mqtt_user where username = '%u' limit 1`

Description

The SQL select statement used for super user authentication. All table names and field names in this statement can be modified as appropriate. If and only if the value of the selected field is 1, the user is a super user. In the WHERE clause, the supported placeholders are the same as auth.mysql.auth_query.

auth.mysql.acl_query

Type	Default
string	`select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = '%a' or username = '%u' or username = '$all' or clientid = '%c'`

Description

The SQL selection statement used in ACL verification. All table names and field names in this statement can be modified as appropriate. The placeholders supported in the WHERE clause are as follows:

Tag	Description
`%a`	To be replaced with the client IP address
`%u`	To be replaced with the username specified by the MQTT client in the CONNECT packet
`%c`	To be replaced with the client identifier specified by the MQTT client in the CONNECT packet

emqx-auth-pgsql

auth.pgsql.server

Type	Default
ip	`127.0.0.1:5432`

Description

PostgreSQL server address.

auth.pgsql.pool

Type	Default
integer	8

Description

Database connection thread pool size.

auth.pgsql.username

Type	Default
string	`root`

Description

PostgreSQL username.

auth.pgsql.password

Type	Default
string	-

Description

PostgreSQL password.

auth.pgsql.database

Type	Default
string	`mqtt`

Description

PostgreSQL database name.

auth.pgsql.encoding

Type	Default
string	`utf8`

Description

PostgreSQL database character encoding format.

auth.pgsql.ssl

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to enable TLS connection.

auth.pgsql.ssl_opts.keyfile

Type	Default
string	-

Description

Client private key file path.

auth.pgsql.ssl_opts.certfile

Type	Default
string	-

Description

Client certificate file path.

auth.pgsql.ssl_opts.cacertfile

Type	Default
string	-

Description

Client CA certificate file path.

auth.pgsql.auth_query

Type	Default
string	`select password from mqtt_user where username = '%u' limit 1`

Description

The SQL selection statement used for authentication, that is the same as auth.mysql.auth_query.

auth.pgsql.password_hash

Type	Default
string	`sh256`

Description

The encryption method used for the password stored in the database, that is the same as auth.mysql.password_hash.

auth.pgsql.super_query

Type	Default
string	`select is_superuser from mqtt_user where username = '%u' limit 1`

Description

The SQL select statement used for super user authentication, that is the same as auth.mysql.super_query.

auth.pgsql.acl_query

Type	Default
string	`select allow, ipaddr, username, clientid, access, topic from mqtt_acl where ipaddr = '%a' or username = '%u' or username = '$all' or clientid = '%c'`

Description

The SQL selection statement used in ACL verification, the same as auth.mysql.acl_query.

emqx-auth-redis

auth.redis.type

Type	Optional Value	Default
enum	`single`, `sentinel`, `cluster`	`single`

Description

Redis Service cluster type:

single：Single node service.
sentinel：sentinel pattern.
cluster：cluster pattern.

auth.redis.server

Type	Default
string	`127.0.0.1:6379`

Description

Redis service addresses, if there are multiple, they are separated by commas. For example, 192.168.0.1:6379, 192.168.0.2:6379.

auth.redis.sentinel

Type	Default
string	-

Description

The cluster name in Redis sentinel mode. If it is not in sentinel mode, no configuration is required.

auth.redis.pool

Type	Optional Value	Default
integer	> 0	8

Description

Connection pool size.

auth.redis.database

Type	Default
integer	0

Description

The serial number of the Redis database to be connected.

auth.redis.password

Type	Default
string	-

Description

Redis password.

auth.redis.query_timeout

Type	Default
duration	`5s`

Description

Redis query timeout.

auth.redis.auth_cmd

Type	Default
string	`HMGET mqtt_user:%u password`

Description

Authentication query commands, available placeholders are:

%u: client username.
%c: client ID.
%C: cn of client SSL certificate.
%d: dn of client SSL certificate.

auth.redis.password_hash

Type	Optional Value	Default
enum	`plain`, `md5`, `sha`, `sha256`, `bcrypt`	`plain`

Description

The encoding format of the password field stored by Redis.

auth.redis.super_cmd

Type	Default
string	`HGET mqtt_user:%u is_superuser`

Description

Authentication query commands for superuser, available placeholders are:

%u: client username.
%c: client ID.
%C: cn of client SSL certificate.
%d: dn of client SSL certificate.

auth.redis.acl_cmd

Type	Default
string	`HGETALL mqtt_acl:%u`

Description

ACL query commands. Available placeholders are:

%u: client username.
%c: client ID.

emqx-auth-username

`auth.user.<Number>.username` & `auth.user.<Number>.password`

Type	Default
string	-

Description

The authentication data of the client, where auth.user.<Number>.password is the clear text password. auth.user.<Number>.username and auth.user.<Number>.password of the same <Number> must appear in pairs. <Number> is an integer number used to distinguish authentication data of multiple clients.

auth.user.password_hash

Type	Optional Value	Default
enum	`plain`, `md5`, `sha`, `sha256`	`sha256`

Description

Hash algorithm used when the password is stored in the database. The following options are available:

plain

The password is stored in clear text.

md5

The password is encrypted and stored using the MD5 algorithm.

sha

The password is encrypted and stored using the SHA-1 algorithm.

sha256

The password is encrypted and stored using the SHA-256 algorithm.

emqx-bridge-mqtt

bridge.mqtt.aws.address

Type	Default
string	`127.0.0.1:1883`

Description

Bridge address, supports two formats, for example:

emqx @ 192.168.0.100: EMQ X Broker node name, which means that the message of this node is bridged to another EMQ X node.
192.168.0.100: 1883: IP address and port,which means that the message of the node is bridged to another MQTT server through an MQTT connection.

bridge.mqtt.aws.proto_ver

Type	Optional Value	Default
enum	`mqttv3`, `mqttv4`, `mqttv5`	`mqttv4`

Description

The client protocol version of the MQTT bridge.

bridge.mqtt.aws.start_type

Type	Optional Value	Default
eunm	`manual`, `auto`	`manual`

Description

Start type:

auto: start automatically with the plugin.
manual: start the bridge manually.

bridge.mqtt.aws.bridge_mode

Type	Optional Value	Default
boolean	`true`, `false`	`true`

Description

Whether to enable bridging mode, only MQTT bridging is supported. After being enabled, the MQTT client started by emqx_bridge_mqtt will carry a flag bit when sending a connection message, indicating that this is a bridging client.

Tip

RabbitMQ currently does not support this flag.

bridge.mqtt.aws.clientid

Type	Default
string	`bridge_aws`

Description

The client ID of the MQTT bridge.

bridge.mqtt.aws.clean_start

Type	Optional Value	Default
boolean	`true`, `false`	`true`

Description

The clean_start flag of the MQTT bridge. It indicates whether the client connects to the remote MQTT Broker in the manner of clean session.

bridge.mqtt.aws.username

Type	Default
string	`user`

Description

The username of the MQTT bridge client.

bridge.mqtt.aws.password

Type	Default
string	`passwd`

Description

The password of the MQTT bridge client.

bridge.mqtt.aws.forwards

Type	Default
string	`topic1/#,topic2/#`

Description

Bridge forwarding rules. For example:

topic1/#, topic2/#：emqx_bridge_mqtt will forward all topic messages in EMQ X Broker that match topic1/#，topic2/# .

bridge.mqtt.aws.forward_mountpoint

Type	Default
string	`bridge/aws/${node}/`

Description

The prefix of the forwarding topic. When forwarding the message to the target system, it is supported to add a uniform prefix to the topic.

bridge.mqtt.aws.subscription.1.topic

Type	Default
string	-

Description

Topic of the peer system subscribed.

bridge.mqtt.aws.subscription.1.qos

Type	Optional Value	Default
enum	`0`, `1`, `2`	`1`

Description

QoS of the peer system topic subscribed.

bridge.mqtt.aws.receive_mountpoint

Type	Default
string	`receive/aws/`

Description

The topic prefix of the received message.emqx_bridge_mqtt supports adding a unified topic prefix to the message from the peer.

bridge.mqtt.aws.ssl

Type	Optional Value	Default
boolean	`true`, `false`	`true`

Description

Whether the MQTT bridge client enables SSL.

bridge.mqtt.aws.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

The path of the CA certificate file of the MQTT bridge client.

bridge.mqtt.aws.certfile

Type	Default
string	`etc/certs/client-cert.pem`

Description

The path of the SSL certificate file of the MQTT bridge client.

bridge.mqtt.aws.keyfile

Type	Default
string	`etc/certs/client-key.pem`

Description

The path of the SSL key file of the MQTT bridge client.

bridge.mqtt.aws.ciphers

Type	Default
string	`ECDHE-ECDSA-AES256-GCM-SHA384,ECDHE-RSA-AES256-GCM-SHA384`

Description

Cipher suite supported by SSL handshake.

bridge.mqtt.aws.psk_ciphers

Type	Default
string	`PSK-AES128-CBC-SHA,PSK-AES256-CBC-SHA,PSK-3DES-EDE-CBC-SHA,PSK-RC4-SHA`

Description

Cipher suite supported by SSL PSK handshake.

bridge.mqtt.aws.keepalive

Type	Default
duration	`60s`

Description

Heartbeat interval of the MQTT bridge client.

bridge.mqtt.aws.tls_versions

Type	Default
string	`tlsv1.2,tlsv1.1,tlsv1`

Description

The SSL version of the MQTT bridge client.

bridge.mqtt.aws.reconnect_interval

Type	Default
duration	`30s`

Description

Reconnection interval.

bridge.mqtt.aws.retry_interval

Type	Default
duration	`20s`

Description

QoS 1/2 message retransmission interval.

bridge.mqtt.aws.batch_size

Type	Default
integer	32

Description

The batch size of the EMQ X bridge. The EMQ X bridge mode of emqx_bridge_mqtt supports batch sending of messages to increase throughput.

bridge.mqtt.aws.max_inflight_size

Type	Default
integer	32

Description

Inflight window size.

bridge.mqtt.aws.queue.replayq_dir

Type	Default
string	`etc/emqx_aws_bridge/`

Description

Set the message queue file path. If not configured, only memory storage is used.

bridge.mqtt.aws.queue.replayq_seg_bytes

Type	Default
bytesize	`10MB`

Description

The single file size of the message queue stored on disk.

bridge.mqtt.aws.queue.max_total_size

Type	Default
bytesize	`5GB`

Description

The maximum allowed message queue storage.

emqx-coap

coap.port

Type	Default
integer	5683

Description

Specify the UDP binding port of the CoAP plug-in.

coap.enable_stats

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Enable or disable CoAP statistics function.

coap.dtls.port

Type	Default
integer	5684

Description

Specify the DTLS binding port of the CoAP plugin.

coap.dtls.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

When using DTLS, specify whether to verify the client during the DTLS handshake.

coap.dtls.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

When using DTLS, specify the DTLS private key file.

coap.dtls.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

When using DTLS, specify the DTLS certificate file.

coap.dtls.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

When using DTLS, specify the CA certificate file for DTLS.

coap.dtls.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

When using DTLS, if the client does not have a certificate during the DTLS handshake, whether to let the handshake fail.

coap.dtls.ciphers

Type Default

Description

When using DTLS, specify the Cipher list supported by the DTLS server.

emqx-dashboard

dashboard.default_user.login`&`dashboard.default_user.password

Type	Default
string	-

Description

Default user authentication data of Dashboard. dashboard.default_user.login and dashboard.default_user.password must exist at the same time.

dashboard.listener.http

Type	Default
integer	18083

Description

The listening port of the HTTP listener.

dashboard.listener.http.acceptors

Type	Default
integer	4

Description

The number of listening processes this listener will create.

dashboard.listener.http.max_clients

Type	Default
integer	512

Description

The maximum number of connections allowed by this listener at the same time.

dashboard.listener.http.inet6

Type	Optional Value	Default
enum	`ture`, `false`	`false`

Description

Whether to set the socket to allow IPv6 connections.

dashboard.listener.http.ipv6_v6only

Type	Optional Value	Default
enum	`ture`, `false`	`false`

Description

Whether to restrict the socket that only IPv6 can be ued, and prohibit any IPv4 connections. Only applicable to IPv6 sockets, that is, the value of this configuration item has practical significance only when dashboard.listener.http.inet6 is set to true. It should be noted that on some operating systems, such as Windows, the only allowed value for this configuration item is true.

dashboard.listener.https

Type	Default
integer	18084

Description

The listening port of the HTTPS listener, which is disabled by default.

dashboard.listener.https.acceptors

Type	Default
integer	2

Description

Same as dashboard.listener.http.acceptors.

dashboard.listener.https.max_clients

Type	Default
integer	512

Description

Same as dashboard.listener.http.max_clients.

dashboard.listener.https.inet6

Type	Optional Value	Default
enum	`ture`, `false`	`false`

Description

Same as dashboard.listener.http.inet6.

dashboard.listener.https.ipv6_v6only

Type	Optional Value	Default
enum	`ture`, `false`	`false`

Description

Same as dashboard.listener.http.ipv6_v6only.

dashboard.listener.https.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

Server private key file path.

dashboard.listener.https.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

Server certificate file path.

dashboard.listener.https.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

CA certificate file path.

dashboard.listener.https.dhfile

Type	Default
string	`etc/certs/dh-params.pem`

Description

If a cipher suite exchanged from Diffie Hellman key is used, you can use this configuration item to specify a file path that contains PEM-encoded Diffie Hellman parameters. If not specified, the default parameters are used.

dashboard.listener.https.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

verify_none means to disable peer certificate verification, and the server will not send a certificate request to the client. verify_peer means to enable peer certificate verification, and the server will send a certificate request to the client. When this configuration item is set to verify_peer, it usually need to be used together with dashboard.listener.https.fail_if_no_peer_cert to specify whether to force the client to provide a certificate.

dashboard.listener.https.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`ture`, `false`	`true`

Description

It should be used together with dashboard.listener.https.verify. If set to true, the server will request a certificate from the client. If the client does not provide a certificate, the handshake will fail. If set to false, the handshake can be successful even if the terminal does not provide a certificate.

dashboard.listener.https.tls_versions

Type	Default
string	`tlsv1.2,tlsv1.1,tlsv1`

Description

Specify the TLS protocol version supported by the server. The versions are separated by ,. The supported TLS protocol versions are: tlsv1.3, tlsv1.2, tlsv1.1, tlsv1, sslv3.

dashboard.listener.https.ciphers

Type Default

Description

Specify the cipher suite supported by the server.

dashboard.listener.https.secure_renegotiate

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Specifies whether to start the secure renegotiation mechanism.

dashboard.listener.https.reuse_sessions

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Specifies whether to enable the session resuing mechanism.

dashboard.listener.https.honor_cipher_order

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

If set to on, use the server ’s preferences for password selection. If set to off, use the client ’s preferences.

emqx-lwm2m

lwm2m.port

Type	Default
integer	5683

Description

Specify the UDP port used by LwM2M.

lwm2m.lifetime_min

Type	Default
duration	`1s`

Description

Specify the minimum allowed LwM2M lifetime with the unit of second.

lwm2m.lifetime_max

Type	Default
duration	`86400s`

Description

Specify the maximum allowed LwM2M lifetime with the unit of second.

lwm2m.qmode_time_window

Type	Default
integer	22

Description

Specifies the window size used in LwM2M Q mode, with the unit of second.

Within this window period, it can be sent to the Q mode device, and after the window period, the downlink data is cached.

lwm2m.lb

Type	Optional Value	Default
enum	`coaproxy`, `undefined`	`undefined`

Description

Set whether to use coaproxy. undefined means not to use coaproxy.

lwm2m.auto_observe

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to automatically issue the observe command after device registration.

lwm2m.mountpoint

Type	Default
string	`lwm2m/%e/`

Description

Set the mount point of the LwM2M topic. The following wildcards are supported:

'%e': Endpoint Name
'%a': IP Address

lwm2m.topics.command

Type	Default
string	`dn/#`

Description

The command line topic that need to be subscribd after the device registration is completed.

lwm2m.topics.response

Type	Default
string	`up/resp`

Description

Which topic the device's upstream response needs to be published to.

lwm2m.topics.notify

Type	Default
string	`up/notify`

Description

Which topic the device's upstream report message (notify) needs to be published to.

lwm2m.topics.register

Type	Default
string	`up/resp`

Description

Which topic the device's upstream registration message (register) needs to be published to.

lwm2m.topics.update

Type	Default
string	`up/resp`

Description

Which topic the device's upstream update message (update) needs to be published to.

lwm2m.opts.buffer

Type	Default
bytesize	`1024KB`

Description

UDP tuning parameters, specify the UDP user mode cache size.

lwm2m.opts.recbuf

Type	Default
bytesize	`1024KB`

Description

UDP tuning parameters, specify the UDP receiving buffer size.

lwm2m.opts.sndbuf

Type	Default
bytesize	`1024KB`

Description

UDP tuning parameters, specify the UDP sending buffer size.

lwm2m.opts.read_packets

Type	Default
integer	20

Description

UDP tuning parameters, specify how many packets to read from UDP socket each time.

lwm2m.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

Specify the certificate file used by UDP DTLS.

lwm2m.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

Specify the private key file used by UDP DTLS.

lwm2m.xml_dir

Type	Default
dir	`etc/lwm2m_xml`

Description

Specify the directory where the LwM2M Object definition file is stored.

emqx-management

management.max_row_limit

Type	Default
integer	10000

Description

Maximum number of records returned during paging query.

management.default_application.id

Type	Default
string	`admin`

Description

Default AppId.

management.default_application.secret

Type	Default
string	`public`

Description

Default AppSecret.

management.listener.http

Type	Default
integer	8081

Description

The listening port of the HTTP listener.

management.listener.http.acceptors

Type	Default
integer	2

Description

The number of listening processes this listener will create.

management.listener.http.max_clients

Type	Default
integer	512

Description

The maximum number of connections allowed by this listener at the same time

management.listener.http.backlog

Type	Default
integer	512

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

management.listener.http.send_timeout

Type	Default
duration	`15s`

Description

HTTP packet sending timeout.

management.listener.http.send_timeout_close

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after the HTTP packet sending is timeout.

management.listener.http.inet6

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to set the socket to allow IPv6 connections.

management.listener.http.ipv6_v6only

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

management.listener.https

Type	Default	Example
integer	-	8081

Description

The listening port of the HTTPS listener.

management.listener.https.acceptors

Type	Default
integer	2

Description

The number of listening processes this listener will create.

management.listener.https.max_clients

Type	Default
integer	512

Description

The maximum number of connections allowed by this listener at the same time.

management.listener.https.backlog

Type	Default
integer	512

Description

The maximum length of the TCP connection queue. It indicates the maximum number of TCP connection queues that are allowed in the system to undergo three-time handshake.

management.listener.https.send_timeout

Type	Default
duration	`15s`

Description

Timeout for sending HTTPS packets.

management.listener.https.send_timeout_close

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Whether to close the connection after the HTTPS packet sending is timeout.

management.listener.https.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

Server private key file path.

management.listener.https.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

Server certificate file path.

management.listener.https.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

CA certificate file path.

management.listener.https.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

management.listener.https.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`ture`, `false`	`true`

Description

It should be used together with management.listener.https.verify. If set to true, the server will fail the handshake if the client does not provide a certificate when requesting a certificate from the client. If set to false, the handshake can be successful even if the terminal does not provide a certificate.

management.listener.https.inet6

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Whether to set the socket to allow IPv6 connections.

management.listener.https.ipv6_v6only

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

emqx-reloader

reloader.interval

Type	Default
duration	`60s`

Description

How often do hot update all code.

reloader.logfile

Type	Default
string	`reloader.log`

Description

Log files for hot updates of code.

emqx-retainer

retainer.storage_type

Type	Optional Value	Default
enum	`ram`, `disc`, `disc_only`	`ram`

Description

Storage type of the message, the following options are available:

ram

Retained messages are only stored in memory.

disc

Retained messages are stored in both memory and disk.

disc_only

Retained messages are only stored on disk.

retainer.max_retained_messages

Type	Default
integer	0

Description

Limit of retained messages. Once the number of stored messages reaches the limit, you can replace existing retained messages, but you cannot store retained messages for new topics. 0 means no limit.

retainer.max_payload_size

Type	Default
bytesize	`1MB`

Description

The maximum length of Payload allowed to store retained messages. If the Payload exceeds the maximum limit, the retained message can be processed normally, but it will not be stored on the server.

retainer.expiry_interval

Type	Default
duration	`0`

Description

The expiration interval of retained messages which is only valid for clients with protocol versions lower than MQTT v5.0. The expiration interval of retained messages for MQTT v5.0 clients will be based on the value of Message Expiry Interval. 0 means never expire.

emqx-rule-engine

rule_engine.ignore_sys_message

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

Ignore system messages ($ SYS). The rule engine will not process system messages if this option is enabled.

rule_engine.events.<event-name>

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Set whether to publish event messages. You can specify the QoS of event messages, for example:

rule_engine.events.client_connected = on, qos1

If this option is enabled, the rules engine will publish system messages using the topic of $events/\<event-name>. Supported <event-name> are:

client_connected
client_disconnected
session_subscribed
session_unsubscribed
message_delivered
message_acked
message_dropped

If this option is disabled, event messages will not be published, but event rules can still be used. For example, even if rule_engine.events.client_connected = off, the following rules can still be used:

SELECT * FROM "$events/client_connected"

emqx-sn

mqtt.sn.port

Type	Default
string	`1884`

Description

The UDP port that emqx_sn listens on.

mqtt.sn.advertise_duration

Type	Default
duration	`15s`

Description

ADVERTISE message broadcast interval, unit: second.

mqtt.sn.gateway_id

Type	Default
integer	1

Description

MQTT-SN gateway ID in ADVERTISE.

mqtt.sn.enable_stats

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to enable client status statistics.

mqtt.sn.enable_qos3

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Whether to process messages with QoS of -1.

mqtt.sn.idle_timeout

Type	Default
duration	`30s`

Description

The idle time after the establishment, if no message is received within this time, the connection will be closed.

mqtt.sn.predefined.topic.0

Type	Default
string	`reserved`

Description

The predefined mapping of Topic and TopicId. Topics with an Id of 0 are reserved and fixed to reserved. For example, the Id of the predefined topic foo / bar is 1:

mqtt.sn.predefined.topic.1 = foo/bar

mqtt.sn.username

Type	Default
string	`mqtt_sn_user`

Description

emqx_sn username to connect to EMQ X Broker.

mqtt.sn.password

Type	Default
string	`abc`

Description

emqx_sn password to connect to EMQ X Broker.

emqx-statsd

statsd.push.gateway.server

Type	Default
string	`http://127.0.0.1:9091`

Description

Specify the URI of the Statsd gateway.

statsd.interval

Type	Default
integer	15000

Description

Specify the collection interval of Statsd data in milliseconds.

prometheus.collector.<N>

Type	Default
string	`emqx_statsd`

Description

Specify Prometheus Collector.

emqx-stomp

stomp.listener

Type	Default
integer	61613

Description

Specify the local port where the Stomp plugin listens.

stomp.listener.acceptors

Type	Default
integer	4

Description

Specify the size of the thread pool for Stomp service Acceptor

stomp.listener.max_connections

Type	Default
integer	512

Description

Specify the maximum number of connections supported by the Stomp service.

stomp.listener.ssl

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

Specify whether to use SSL.

stomp.listener.keyfile

Type	Default
string	`etc/certs/key.pem`

Description

If using SSL, specify the SSL private key file.

stomp.listener.certfile

Type	Default
string	`etc/certs/cert.pem`

Description

If using SSL, specify the SSL certificate file.

stomp.listener.cacertfile

Type	Default
string	`etc/certs/cacert.pem`

Description

If using SSL, specify the CA certificate file for SSL.

stomp.listener.dhfile

Type	Default
string	`etc/certs/dh-params.pem`

Description

If using SSL, specify the key file used by the Ephemeral Diffie-Hellman algorithm.

stomp.listener.verify

Type	Optional Value	Default
enum	`verify_peer`, `verify_none`	`verify_peer`

Description

If using SSL, specify whether to verify the client during the handshake.

stomp.listener.fail_if_no_peer_cert

Type	Optional Value	Default
enum	`true`, `false`	`false`

Description

Specify whether the handshake fail if SSL is used, and the client does not have a certificate during the SSL handshake.

stomp.listener.tls_versions

Type	Default
string	`tlsv1.2,tlsv1.1,tlsv1`

Description

If using SSL, specify the list of SSL versions supported by the server.

stomp.listener.handshake_timeout

Type	Default
duration	`15s`

Description

If using SSL, specify the timeout period for the SSL handshake process.

stomp.listener.ciphers

Type Default

Description

If using SSL, specify the Cipher list supported by the server

stomp.listener.secure_renegotiate

Type	Optional Value	Default
enum	`on`, `off`	`off`

Description

If using SSL, specify whether to reject the renegotiation request if the client does not follow RFC 5746.

stomp.listener.reuse_sessions

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

If using SSL, specify whether to support SSL session reuse.

stomp.listener.honor_cipher_order

Type	Optional Value	Default
enum	`on`, `off`	`on`

Description

If using SSL, specify whether to use the server's preferences to select Ciphers.

Type	Default
string	`guest`

Description

Specify the Username used by the Stomp plugin to log in.

stomp.default_user.passcode

Type	Default
string	`guest`

Description

Specify the password used for Stomp plugin login.

stomp.allow_anonymous

Type	Optional Value	Default
enum	`true`, `false`	`true`

Description

Whether to allow anonymous login.

stomp.frame.max_headers

Type	Default
integer	10

Description

Specify the maximum number of Stomp headers

stomp.frame.max_header_length

Type	Default
integer	1024

Description

Specify the maximum Stomp header length

stomp.frame.max_body_length

Type	Default
integer	8192

Description

Specify Stomp maximum message body length.

emqx-web-hook

web.hook.api.url

Type	Default
string	-

Description

emqx_web_hook Forwarding web server address.

web.hook.encode_payload

Type	Optional Value	Default
enum	`base62`, `base64`	-

Description

The encoding format of the Payload field in the PUBLISH message.

web.hook.rule.client.connect.1

Type	Default
string	`{"action": "on_client_connect"}`

Description

Forward the on_client_connect event.

web.hook.rule.client.connack.1

Type	Default
string	`{"action": "on_client_connack"}`

Description

Forward the on_client_connack event.

web.hook.rule.client.connected.1

Type	Default
string	`{"action": "on_client_connected"}`

Description

Forward the on_client_connected event.

web.hook.rule.client.disconnected.1

Type	Default
string	`{"action": "on_client_disconnected"}`

Description

Forward the on_client_disconnected event.

Type	Default
string	`{"action": "on_client_subscribe"}`

Description

Forward the on_client_subscribe event.

web.hook.rule.client.unsubscribe.1

Type	Default
string	`{"action": "on_client_unsubscribe"}`

Description

Forward the on_client_unsubscribe event.

web.hook.rule.session.subscribed.1

Type	Default
string	`{"action": "on_session_subscribed"}`

Description

Forward the on_client_subscribe event.

web.hook.rule.session.unsubscribed.1

Type	Default
string	`{"action": "on_session_unsubscribed"}`

Description

Forward the on_session_unsubscribe event.

web.hook.rule.session.terminated.1

Type	Default
string	`{"action": "on_session_terminated"}`

Description

Forward the on_session_terminated event.

web.hook.rule.message.publish.1

Type	Default
string	`{"action": "on_message_publish"}`

Description

Forward the on_client_publish event.

web.hook.rule.message.delivered.1

Type	Default
string	`{"action": "on_message_delivered"}`

Description

Forward the on_message_delivered event.

web.hook.rule.message.acked.1

Type	Default
string	`{"action": "on_message_acked"}`

Description

Forward the on_message_acked event.

Configuration ​

cluster ​

cluster.name ​

Description ​

cluster.proto_dist ​

Description ​

cluster.discovery ​

Description ​

cluster.autoheal ​

Description ​

cluster.autoclean ​

Description ​

cluster.static.seeds ​

Description ​

cluster.mcast.addr ​

Description ​

cluster.mcast.ports ​

Description ​

cluster.mcast.iface ​

Description ​

cluster.mcast.ttl ​

Description ​

cluster.mcast.loop ​

Description ​

cluster.dns.name ​

Description ​

Example ​

cluster.dns.app ​

Description ​

cluster.etcd.server ​

Description ​

cluster.etcd.prefix ​

Description ​

cluster.etcd.node_ttl ​

Description ​

cluster.etcd.ssl.keyfile ​

Description ​

cluster.etcd.ssl.certfile ​

Description ​

cluster.etcd.ssl.cacertfile ​

Description ​

cluster.k8s.apiserver ​

Description ​

cluster.k8s.service_name ​

Description ​

cluster.k8s.address_type ​

Description ​

Example ​

cluster.k8s.app_name ​

Description ​

cluster.k8s.suffix ​

Description ​

cluster.k8s.namespace ​

Description ​

Example ​

node.name ​

Description ​

node.cookie ​

Description ​

node.data_dir ​

Description ​

node.heartbeat ​

Description ​

node.async_threads ​

Description ​

node.process_limit ​

Description ​

node.max_ports ​

Description ​

node.dist_buffer_size ​

Description ​

node.max_ets_tables ​

Description ​

node.global_gc_interval ​

Description ​

node.fullsweep_after ​

Description ​

node.crash_dump ​

Description ​

node.ssl_dist_optfile ​

Configuration

cluster

cluster.name

Description

cluster.proto_dist

Description

cluster.discovery

Description

cluster.autoheal

Description

cluster.autoclean

Description

cluster.static.seeds

Description

cluster.mcast.addr

Description

cluster.mcast.ports

Description

cluster.mcast.iface

Description

cluster.mcast.ttl

Description

cluster.mcast.loop

Description

cluster.dns.name

Description

Example

cluster.dns.app

Description

cluster.etcd.server

Description

cluster.etcd.prefix

Description

cluster.etcd.node_ttl

Description

cluster.etcd.ssl.keyfile

Description

cluster.etcd.ssl.certfile

Description

cluster.etcd.ssl.cacertfile

Description

cluster.k8s.apiserver

Description

cluster.k8s.service_name

Description

cluster.k8s.address_type

Description

Example

cluster.k8s.app_name

Description

cluster.k8s.suffix

Description

cluster.k8s.namespace

Description

Example

node.name

Description

node.cookie

Description

node.data_dir

Description

node.heartbeat

Description

node.async_threads

Description

node.process_limit

Description

node.max_ports

Description

node.dist_buffer_size

Description

node.max_ets_tables

Description

node.global_gc_interval

Description

node.fullsweep_after

Description

node.crash_dump

Description

node.ssl_dist_optfile