The Log JMX Metrics scheduled job sends JMX metrics to atlassian-confluence-jmx.log log file. More about it on Live Monitoring Using the JMX Interface.

Steps to Reproduce

1. In an instance running Confluence 7.17 or higher, validate the "Log JMX Metrics" is enabled:
   1. Go to Administration > General configuration > Scheduled jobs.
   2. Search for the Log JMX Metrics and validate that its status is Enabled.
   3. If it is Disabled, enable it.

Expected Results

The metrics described in Live Monitoring Using the JMX Interface are written to atlassian-confluence-jmx.log:

• CacheStatistics
• IndexingStatistics
• MailTaskQueue
• RequestMetrics
• SystemInformation
• ThreadPool
• OS
• GC
• Threading
• TomcatManager
• RequestProcessor

Actual Results

Metrics ThreadPool, TomcatManager, and RequestProcessor are not written to atlassian-confluence-jmx.log leaving them blank in the file:

2024-04-30 18:46:00,044 ThreadPool: []
2024-04-30 18:46:00,044 TomcatManager: []
2024-04-30 18:46:00,044 RequestProcessor: []

 
2024-04-30 18:47:00,069 ThreadPool: []
2024-04-30 18:47:00,070 TomcatManager: []
2024-04-30 18:47:00,070 RequestProcessor: []

Workaround

Manually edit Tomcat's server.xml to switch the Engine name from Standalone to Catalina:

<Engine name="Catalina" defaultHost="localhost" debug="0">

After the changes are done, restart Confluence.

If running Confluence DC, repeat the same procedure for each node in the cluster.