#Tomcat

Plugin: go.d.plugin Module: tomcat

#Overview

This collector monitors Tomcat metrics about bandwidth, processing time, threads and more.

It parses the information provided by the Server Status HTTP endpoint.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

By default, this Tomcat collector cannot access the server's status page. To enable data collection, you will need to configure access credentials with appropriate permissions.

#Default Behavior

#Auto-Detection

If the Netdata Agent and Tomcat are on the same host, the collector will attempt to connect to the Tomcat server's status page at http://localhost:8080/manager/status?XML=true.

#Limits

The default configuration for this integration does not impose any limits on data collection.

#Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

#Setup

You can configure the tomcat collector in two ways:

Method	Best for	How to
UI	Fast setup without editing files	Go to Nodes → Configure this node → Collectors → Jobs, search for tomcat, then click + to add a job.
File	If you prefer configuring via file, or need to automate deployments (e.g., with Ansible)	Edit go.d/tomcat.conf and add a job.

:::important

UI configuration requires paid Netdata Cloud plan.

:::

#Prerequisites

#Access to Tomcat Status Endpoint

The Netdata Agent needs read-only access to its status endpoint to collect data from the Tomcat server.

You can achieve this by creating a dedicated user named netdata with read-only permissions specifically for accessing the Server Status endpoint.

Once you've created the netdata user, you'll need to configure the username and password in the collector configuration file.

#Configuration

#Options

The following options can be defined globally: update_every, autodetection_retry.

Config options

| Group | Option | Description | Default | Required | |:------|:-----|:------------|:--------|:---------:| | **Collection** | update_every | Data collection interval (seconds). | 1 | no | | | autodetection_retry | Autodetection retry interval (seconds). Set 0 to disable. | 0 | no | | **Target** | url | Target endpoint URL. | http://127.0.0.1:8080 | yes | | | timeout | HTTP request timeout (seconds). | 1 | no | | **HTTP Auth** | username | Username for Basic HTTP authentication. | | no | | | password | Password for Basic HTTP authentication. | | no | | | bearer_token_file | Path to a file containing a bearer token (used for `Authorization: Bearer`). | | no | | **TLS** | tls_skip_verify | Skip TLS certificate and hostname verification (insecure). | no | no | | | tls_ca | Path to CA bundle used to validate the server certificate. | | no | | | tls_cert | Path to client TLS certificate (for mTLS). | | no | | | tls_key | Path to client TLS private key (for mTLS). | | no | | **Proxy** | proxy_url | HTTP proxy URL. | | no | | | proxy_username | Username for proxy Basic HTTP authentication. | | no | | | proxy_password | Password for proxy Basic HTTP authentication. | | no | | **Request** | method | HTTP method to use. | GET | no | | | body | Request body (e.g., for POST/PUT). | | no | | | headers | Additional HTTP headers (one per line as key: value). | | no | | | not_follow_redirects | Do not follow HTTP redirects. | no | no | | | force_http2 | Force HTTP/2 (including h2c over TCP). | no | no | | **Virtual Node** | vnode | Associates this data collection job with a [Virtual Node](https://learn.netdata.cloud/docs/netdata-agent/configuration/organize-systems-metrics-and-alerts#virtual-nodes). | | no |

#via UI

Configure the tomcat collector from the Netdata web interface:

1. Go to Nodes.
2. Select the node where you want the tomcat data-collection job to run and click the :gear: (Configure this node). That node will run the data collection.
3. The Collectors → Jobs view opens by default.
4. In the Search box, type tomcat (or scroll the list) to locate the tomcat collector.
5. Click the + next to the tomcat collector to add a new job.
6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
   • Test runs the job with the provided settings and shows whether data can be collected.
   • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

#via File

The configuration file name for this integration is go.d/tomcat.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/tomcat.conf

#Examples

#Basic

A basic example configuration.

jobs:
  - name: local
    url: http://127.0.0.1:8080
    username: John
    password: Doe

#Multi-instance

Note: When you define multiple jobs, their names must be unique.

Collecting metrics from local and remote instances.

Config

```yaml jobs: - name: local url: http://127.0.0.1:8080 username: admin1 password: hackme1 - name: remote url: http://192.0.2.1:8080 username: admin2 password: hackme2 ```

#Alerts

There are no alerts configured by default for this integration.

#Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

#Per Tomcat instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
tomcat.jvm_memory_usage	free, used	bytes

#Per jvm memory pool

These metrics refer to the JVM memory pool.

Labels:

Label	Description
mempool_name	Memory Pool name.
mempool_type	Memory Pool type.

Metrics:

Metric	Dimensions	Unit
tomcat.jvm_mem_pool_memory_usage	commited, used, max	bytes

#Per connector

These metrics refer to the connector.

Labels:

Label	Description
connector_name	Connector name.

Metrics:

Metric	Dimensions	Unit
tomcat.connector_requests	requests	requests/s
tomcat.connector_bandwidth	received, sent	bytes/s
tomcat.connector_requests_processing_time	processing_time	milliseconds
tomcat.connector_errors	errors	errors/s
tomcat.connector_request_threads	idle, busy	threads

#Troubleshooting

#Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the tomcat collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m tomcat

To debug a specific job:

  ./go.d.plugin -d -m tomcat -j jobName

#Getting Logs

If you're encountering problems with the tomcat collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

#System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep tomcat

#System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep tomcat /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

#Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep tomcat