To view cache metrics and monitor usage in real-time:
- Click the arrow next to External Resource Cache Settings and select External Resource Cache Status. A side panel will appear showing cache metrics.
- Use the drop-down to view metrics per node or across the cluster.
The metrics include the following:
- Memory Usage: Total memory currently used by the cache.
- Cache Entries: Total number of stored cache results.
- Cache Hits: Number of times EMQX found a valid result in the cache, avoiding a call to the external backend.
- Metrics shown: Current rate, 5-minute average, Maximum rate
- Cache Misses: Number of times EMQX looked for a result in the cache but didn’t find one, resulting in a backend query.
- Metrics shown: Current rate, 5-minute average, Maximum rate
- Cache Inserts: Number of new results added to the cache after a miss.
- Metrics shown: Current rate, 5-minute average, Maximum rate
At the bottom of the panel, a node list provides an overview of Memory Usage, Cache Entries, and Cache Hits for each node in the cluster.
You can refresh or reset the statistics using the buttons in the top-right corner of the panel.