Apache Tomcat

OpsVerse ObserveNow can pull logs and metrics from Apache Tomcat using the jmx_exporter that can be configured using the OpsVerse Agent. Please follow the steps below to configure the agent to monitor your Tomcat installation

Prerequisite: OpsVerse ObserveNow Agent installed on the VM running Tomcat following the steps mentioned here

Assuming you have the ObserveNow agent up and running on the VM, you can follow the nest steps to configure Tomcat observability

Metrics

Install the JMX Exporter

# for amd64
curl https://raw.githubusercontent.com/OpsVerseIO/installers/main/prometheus-exporters/install-exporter-amd64.sh | sudo bash -s -- -e jmx  

# for arm64
curl https://raw.githubusercontent.com/OpsVerseIO/installers/main/prometheus-exporters/install-exporter-arm64.sh | sudo bash -s -- -e jmx

Configure JMX Exporter for Tomcat

Open /etc/opsverse/exporters/jmx/config.yaml and add the following config into it:

lowercaseOutputLabelNames: true
lowercaseOutputName: true
whitelistObjectNames: ["java.lang:type=OperatingSystem", "Catalina:*"]
blacklistObjectNames: []
rules:
  - pattern: 'Catalina<type=Server><>serverInfo: (.+)'
    name: tomcat_serverinfo
    value: 1
    labels:
      serverInfo: "$1"
    type: COUNTER
  - pattern: 'Catalina<type=GlobalRequestProcessor, name=\"(\w+-\w+)-(\d+)\"><>(\w+):'
    name: tomcat_$3_total
    labels:
      port: "$2"
      protocol: "$1"
    help: Tomcat global $3
    type: COUNTER
  - pattern: 'Catalina<j2eeType=Servlet, WebModule=//([-a-zA-Z0-9+&@#/%?=~_|!:.,;]*[-a-zA-Z0-9+&@#/%=~_|]), name=([-a-zA-Z0-9+/$%~_-|!.]*), J2EEApplication=none, J2EEServer=none><>(requestCount|processingTime|errorCount):'
    name: tomcat_servlet_$3_total
    labels:
      module: "$1"
      servlet: "$2"
    help: Tomcat servlet $3 total
    type: COUNTER
  - pattern: 'Catalina<type=ThreadPool, name="(\w+-\w+)-(\d+)"><>(currentThreadCount|currentThreadsBusy|keepAliveCount|connectionCount|acceptCount|acceptorThreadCount|pollerThreadCount|maxThreads|minSpareThreads):'
    name: tomcat_threadpool_$3
    labels:
      port: "$2"
      protocol: "$1"
    help: Tomcat threadpool $3
    type: GAUGE
  - pattern: 'Catalina<type=Manager, host=([-a-zA-Z0-9+&@#/%?=~_|!:.,;]*[-a-zA-Z0-9+&@#/%=~_|]), context=([-a-zA-Z0-9+/$%~_-|!.]*)><>(processingTime|sessionCounter|rejectedSessions|expiredSessions):'
    name: tomcat_session_$3_total
    labels:
      context: "$2"
      host: "$1"
    help: Tomcat session $3 total
    type: COUNTER

Configure Tomcat to use JMX Exporter

In the same directory where catalina.sh is, create a file named setenv.sh (usually /opt/tomcat/bin/) and add the following into the directory

#! /bin/sh
export CATALINA_OPTS="$CATALINA_OPTS -javaagent:/usr/local/bin/jmx_prometheus_javaagent-1.1.0.jar=9404:/etc/opsverse/exporters/jmx/config.yaml"

Ensure the file is executable using the command chmod +x setenv.sh

Restart Tomcat and in a few seconds you should start seeing Tomcat metrics in the Metrics Explorer in your ObserveNow Grafana

Logs

Configure Observe Agent

To pull Apache Tomcat logs into ObserveNow, you only need to add a new block to the agent config. Open up /etc/opsverse/agent-config.yaml and under logs -> configs -> scrape_ configs add the following block:

- job_name: tomcat
  static_configs:
    - labels:
        job: tomcat
        host: <hostname> # Add unique hostname
        __path__: /opt/tomcat/logs/* # This path may be different depending on how Tomcat was installed

Restart Observe Agent

Restart Observe Agent with sudo systemctl restart opsverse-agent and you should see logs in your ObserveNow Grafana under the Logs datasource with the label job = tomcat