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This option enables the provision of JITServer performance metrics to a monitoring agent that follows the OpenMetrics standard.

When you enable this option, the following JITServer metrics are provided:

  • The CPU utilization of the JITServer
  • The physical memory that is available to the JITServer
  • The number of clients that are connected to the JITServer
  • The number of active compilation threads in the JITServer

Note: The data is currently not encrypted.


Setting Effect Default
-XX:+JITServerMetrics Enable
-XX:-JITServerMetrics Disable yes


When you enable this option, the JITServer process opens a TCP port, which can be used by monitoring agents (like Prometheus) to collect the custom metrics exported by the JITServer. Monitoring agents must issue HTTP GET requests to a URL of the form: http://<jitserveraddress>:<port>/metrics. The path for the HTTP request must be /metrics.

The default value of <port> is 38500. You can change this value by using the -XX:JITServerMetricsPort command line option.

The format for the metrics returned by the JITServer follows the OpenMetrics protocol.


The following example shows an HTTP request from a Prometheus monitoring agent and the response from the JITServer:

HTTP request:

GET /metrics HTTP/1.1 Host: User-Agent: Prometheus/2.31.1 Accept: application/openmetrics-text; version=0.0.1,text/plain;version=0.0.4;q=0.5,*/*;q=0.1 Accept-Encoding: gzip X-Prometheus-Scrape-Timeout-Seconds: 3

JITServer response:

# HELP jitserver_cpu_utilization Cpu utilization of the JITServer # TYPE jitserver_cpu_utilization gauge jitserver_cpu_utilization 12.000000 # HELP jitserver_available_memory Available memory for JITServer # TYPE jitserver_available_memory gauge jitserver_available_memory 32036204544.000000 # HELP jitserver_connected_clients Number of connected clients # TYPE jitserver_connected_clients gauge jitserver_connected_clients 1.000000 # HELP jitserver_active_threads Number of active compilation threads # TYPE jitserver_active_threads gauge jitserver_active_threads 1.000000

See also