Apache Tomcat, often referred to as Tomcat Server, is an open-source Java Servlet Container developed by the Apache Software Foundation (ASF). Tomcat implements several Java EE specifications including Java Servlet, JavaServer Pages (JSP), Java EL, and WebSocket, and provides a “pure Java” HTTP web server environment in which Java code can run.
This integration will monitor your key Tomcat metrics and availability via JMX so your Tomcat server will need to have JMX enabled as per the integration instructions provided.
Once enabled you will get a host of Tomcat performance metrics out of the box, and a default Dashboard template to help you get started monitoring your key Tomcat performance metrics.
| Metric Name | MBean Query | Type | Labels | Unit | Description |
|---|---|---|---|---|---|
| tomcat.threadpool_maxthreads | Catalina:type=ThreadPool, name=*/maxThreads | Gauge | processor | The maximum number of allowed worker threads. | |
| tomcat.threadpool_current_thread_count | Catalina:type=ThreadPool, name=*/currentThreadCount | Gauge | processor | The number of threads managed by the thread pool. | |
| tomcat.threadpool_current_threads_busy | Catalina:type=ThreadPool, name=*/currentThreadsBusy | Gauge | processor | The number of threads that are in use. | |
| tomcat.global_request_processor_bytessent | Catalina:type=GlobalRequestProcessor, name=*/BytesSent | Counter | processor | byte | Bytes per second sent per request processor. |
| tomcat.global_request_processor_bytesreceived | Catalina:type=GlobalRequestProcessor, name=*/BytesReceived | Counter | processor | byte | Bytes per second received per request processor. |
| tomcat.global_request_processor_processingtime | Catalina:type=GlobalRequestProcessor, name=*/ProcessingTime | Gaugue | processor | millisecond | The sum of request processing times across all requests handled by the request processors (in milliseconds) per second. |
| tomcat.global_request_processor_requestcount | Catalina:type=GlobalRequestProcessor, name=*/RequestCount | Counter | processor | Bytes per second received per request processor. | |
| tomcat.global_request_processor_errorcount | Catalina:type=GlobalRequestProcessor, name=*/ErrorCount | Counter | processor | The number of erroneous requests received by the servlet per second. | |
| tomcat.global_request_processor_maxtime | Catalina:type=GlobalRequestProcessor, name=*/MaxTime | Gauge | processor | millisecond | The longest request processing time (in milliseconds). |
| tomcat.cache_access_count | Catalina:type=Cache,host=, context=/accessCount | Counter | tomcat_host, context | The number of accesses to the cache per second. | |
| tomcat.cache_hits_count | Catalina:type=Cache,host=, context=/hitsCount | Counter | tomcat_host, context | The number of cache hits per second. | |
| tomcat.servlet_processingTime | Catalina:j2eeType=Servlet, name=,WebModule=, */processingTime | Counter | webmodule, servlet | millisecond | The sum of request processing times across all requests to the servlet (in milliseconds) per second. |
| tomcat.servlet_errorCount | Catalina:j2eeType=Servlet, name=,WebModule=, */errorCount | Counter | webmodule, servlet | The number of erroneous requests received by the servlet per second. | |
| tomcat.servlet_requestCount | Catalina:j2eeType=Servlet, name=,WebModule=, */requestCount | Counter | webmodule, servlet | The number of requests received by the servlet per second. | |
| tomcat.jspmonitor_jsp_count | Catalina:type=JspMonitor, name=jsp,WebModule=*, */jspCount | Counter | webmodule | The number of JSPs per second that have been loaded in the web module. | |
| tomcat.jspmonitor_jsp_reload_count | Catalina:type=JspMonitor, name=jsp,WebModule=*, */jspReloadCount | Counter | webmodule | The number of JSPs per second that have been reloaded in the web module |
This integration requires JMX to be enabled on the Tomcat JVM. How you do this depends on the version of Tomcat you have and how you’re running it.
If you already have JMX Enabled then you can skip to the end of these instructions.
Full instructions for enabling JMX on Tomcat can be found here for Tomcat 7.
Enabling Tomcat JMX on Linux
If you run Tomcat directly via catalina.sh, you can put the JMX ptions into a file called setenv.sh in the same folder.
CATALINA_OPTS=""
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.port=9010"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.rmi.port=9010"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.ssl=false"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.authenticate=false"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.local.only=false"
Enabling Tomcat JMX on Docker
If you’re using the official Tomcat container, you can
enable JMX by passing options in the CATALINA_OPTS environment variable, for example:
CATALINA_OPTS=""
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.port=9012"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.rmi.port=9012"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.ssl=false"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.authenticate=false"
CATALINA_OPTS="${CATALINA_OPTS} -Dcom.sun.management.jmxremote.local.only=false"
docker run -d -e CATALINA_OPTS=$CATALINA_OPTS tomcat:latest
Once enabled, remember to ensure the port 9012 is open so the Outlyer agent can access the port from outside the container.
Enabling Tomcat JMX on Windows
Under your Tomcat installation folder, edit the setenv.bat to include the following:
set CATALINA_OPTS= -Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=9012
-Dcom.sun.management.jmxremote.rmi.port=9012
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.local.only=false
By default the integration plugin will connect to service:jmx:rmi:///jndi/rmi://{jmx_ip}:9012/jmxrmi,
where the jmx_ip is passed in dynamically at runtime by the agent to ensure it connects to the intended instance.
However, if your JMX port is not on port 9012, you can easily override the port using a check variable:
- port: The port Tomcat’s JMX is running on
| Version | Release Date | Description |
|---|---|---|
| 1.0 | 15-May-2018 | Initial version of our Tomcat monitoring integration. |