Data Integration Incompatibility Between EMQX 5.1 and EMQX 4.4

The whole concept of Data Integration was upgraded in EMQX 5.1.

• The previous Rule -> Action -> Resources process is changed to Rules -> Data Bridge.

  In EMQX 4.4, there was a configuration entity for Action. But in EMQX 5.1, when adding an action for a certain rule, you must first create a data bridge and modify the bridge's SQL template to adapt the rule output.

  

• The Modules -> Message Publish is moved into the Data Bridge.

  The Message Publish Module in EMQX 4.4:

  

• Save Offline Message features in EMQX 4.4 are removed.

• Get Subscriptions features in EMQX 4.4 are removed.

• DolphinDB, Lindorm, and SAP Event Mesh data bridges are not supported, but SAP Event Mesh is in the product roadmap.

• EMQX Bridge as a resource type is no longer supported.

  

Common Incompatibility Changes

• All SSL-related configuration options (ssl, cafile, keyfile, certfile, verify) are changed to a unified structure and name. For example, ssl.cacertfile, ssl.certfile, ssl.keyfile, ssl.verify, and etc.
• There is no equivalent functionality as the feature of saving offline messages to an external database and retrieving them when a client subscribes to topics (through the $events/session_subscribed event and bridge rule action).

Incompatibility in Functionality and Configuration Items

This section lists the functionality and configuration items changes for each data bridge.

Cassandra

The configuration name nodes is changed to servers.

Kafka Producer

• Changed configuration items:
  • servers to bootstrap_hosts
  • authentication_mechanism to authentication
  • sync_timeout to sync_query_timeout
  • send_buffer to socket_opts.sndbuf
  • tcp_keepalive to socket.tcp_keepalive
  • strategy to partition_strategy
  • cache_mode to kafka.buffer.mode
  • Buffer mode enum memory+disk to hybrid
  • highmem_drop to kafka.buffer.memory_overload_protection
• No equivalent in EMQX 5.1:
  • query_api_versions
  • kafka_ext_headers
• Nested replayq related options (e.g.: max_batch_bytes) under kafka key
• Now, message key is templatable, whereas before it could be only a few option.

Kafka Consumer

• Changed configuration items:
  • servers to bootstrap_hosts
  • max_bytes to kafka.max_batch_bytes
  • offset_reset_policy enum: {reset_to_latest, reset_by_subscriber} to {latest, earliest}
• There’s no pool_size in EMQX 5.1: the number of workers is set automatically by the lib depending on the number of partitions in the topic(s).
• In EMQX 4.4, only plain SASL was supported for authentication. In EMQX 5.1, the same mechanisms as Kafka Producer is supported.

Pulsar Consumer

There is no Pulsar Consumer in EMQX 5.1.0.

Pulsar Producer

• In EMQX 5.1, the bridge only produces messages using the driver’s async API, without an option for sync API.
• Now, there is a template for the message key. Before, there are only a few options.
• Changed configuration items:
  • Buffer mode enum memory+disk to hybrid
  • max_total_bytes to buffer.per_partition_limit
  • segment_bytes to buffer.segment_bytes

Redis

The configuration item cmd is changed to command_template (common to all 3 Redis Modes).

Changes for "Cluster" mode:

• There is no database field in EMQX 5.1.
• There is no equivalent for ttl (offline messages from EMQX 4.4) in EMQX 5.1.

Postgres

• No differences in connector.
• The batching configuration has moved to resource_opts.* in the Action configuration.
  • enable_batch = true (EMQX 4.4) to resource_opts.batch_size > 1 (EMQX 5.1)
  • batch_time is hidden and defaults to 0 in EMQX 5.1.
  • sql to prepare_statement.

MySQL

• user is changed to username.
• The batching configuration has moved to resource_opts.* in the Action configuration.
  • enable_batch = true (EMQX 4.4) to resource_opts.batch_size > 1 (EMQX 5.1)
  • batch_time is hidden and defaults to 0 in EMQX 5.1.
  • sql to prepare_statement.

MQTT

• Changed configuration items:
  • address to server
  • pool_size to {egress,ingress}.pool_size
  • reconnect_interval to resource_opts.health_check_interval
• No equivalent in EMQX 5.1:
  • append
  • mountpoint
• disk_cache = on (in EMQX 4.4) can be considered somewhat equivalent to setting resource_opts.buffer_mode = volatile_offload, but the latter is a hidden configuration option that defaults to memory_only.
• There is no RPC MQTT bridge equivalent in EMQX 5.1.
• Changed configuration items in Actions:
  • forward_topic to egress.remote.topic
  • payload_tmpl to payload

InfluxDB

The following changes are common to both API v1 and API v2.

• Changed bridge configuration items:

  • host and port are changed to server.
  • https_enabled and ssl options like tls_version are changed to ssl.

• Changed configurations in Actions:

  • There is no equivalent for int_suffix in EMQX 5.1; the type is directly specified in write_syntax.
  • measurement, timestamp, fields, tags are changed to write_syntax.

DolphinDB, Lindorm, SAP Event Mesh

There are no equivalent data bridges in EMQX 5.1.

Clickhouse

Changed configuration items:

• server to url
• user to username
• key to password

Dynamo

• No equivalent for region in EMQX 5.1.
• Now there is payload_template.

HStreamDB

• The configuration item server is changed to url.
• The following items have no equivalents in EMQX 5.1:
  • grpc_timeout
  • partition_key
  • grpc_flush_timeout

IoTDB

Changed configuration items:

• host, rest_port to base_url
• request_timeout to resource_opts.request_ttl

MongoDB

Changed configuration items:

• login to username
• connectTimeoutMS to connect_timeout_ms
• rs_set_name to replica_set_name
• payload_tmpl to payload_template

OpenTSDB

sync is changed to resource_opts.query_mode = sync.

Oracle

user is changed to username.

TDengine

Changed configuration items:

• host, port to server
• dbname to database

GCP PubSub Producer

Deprecated configuration items:

• flush_mode
• flush_period_ms

RabbitMQ Producer

• Changed configuration items:
  • server to host and port
  • payload_tmpl to payload_template
  • durable to delivery_mode
• exchange_type has no equivalent in EMQX 5.1.

RocketMQ

• The following configuration items have no equivalents in EMQX 5.1:
  • namespace
  • strategy
  • key
• Changed configuration items:
  • type to resource_opts.query_mode
  • payload_tmpl to payload_template