Tomcat
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
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
File
The configuration file name for this integration is go.d/tomcat.conf.
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
Options
The following options can be defined globally: update_every, autodetection_retry.
| Name | Description | Default | Required |
|---|---|---|---|
| update_every | Data collection frequency. | 1 | no |
| autodetection_retry | Recheck interval in seconds. Zero means no recheck will be scheduled. | 0 | no |
| url | Server URL. | http://127.0.0.1:8080 | yes |
| timeout | HTTP request timeout. | 1 | no |
| username | Username for basic HTTP authentication. | no | |
| password | Password for basic HTTP authentication. | no | |
| proxy_url | Proxy URL. | no | |
| proxy_username | Username for proxy basic HTTP authentication. | no | |
| proxy_password | Password for proxy basic HTTP authentication. | no | |
| method | HTTP request method. | POST | no |
| body | HTTP request body. | no | |
| headers | HTTP request headers. | no | |
| not_follow_redirects | Redirect handling policy. Controls whether the client follows redirects. | no | no |
| tls_skip_verify | Server certificate chain and hostname validation policy. Controls whether the client performs this check. | no | no |
| tls_ca | Certification authority that the client uses when verifying the server’s certificates. | no | |
| tls_cert | Client TLS certificate. | no | |
| tls_key | Client TLS key. | no |
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.
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
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 |
Alerts
There are no alerts configured by default for this integration.
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.ddirectory, usually at/usr/libexec/netdata/plugins.d/. If that’s not the case on your system, opennetdata.confand look for thepluginssetting under[directories].cd /usr/libexec/netdata/plugins.d/ -
Switch to the
netdatauser.sudo -u netdata -s -
Run the
go.d.pluginto debug the collector:./go.d.plugin -d -m tomcat
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