Datadog-Tomcat Integration

Overview

This check collects Tomcat metrics like:

  • Overall activity metrics: error count, request count, processing times
  • Thread pool metrics: thread count, number of threads busy
  • Servlet processing times

And more.

Setup

Installation

The Tomcat check is packaged with the Agent, so simply install the Agent on your Tomcat servers.

This check is JMX-based, so you’ll need to enable JMX Remote on your Tomcat servers. Follow the instructions in the Tomcat documentation to do that.

Configuration

Create a file tomcat.yaml in the Agent’s conf.d directory. See the sample tomcat.yaml for all available configuration options:

instances:
    -   host: localhost
        port: 7199
        user: <TOMCAT_USERNAME>
        password: <PASSWORD>
        name: my_tomcat

init_config:
  conf:
    - include:
        type: ThreadPool
        attribute:
          maxThreads:
            alias: tomcat.threads.max
            metric_type: gauge
          currentThreadCount:
            alias: tomcat.threads.count
            metric_type: gauge
          currentThreadsBusy:
            alias: tomcat.threads.busy
            metric_type: gauge
    - include:
        type: GlobalRequestProcessor
        attribute:
          bytesSent:
            alias: tomcat.bytes_sent
            metric_type: counter
          bytesReceived:
            alias: tomcat.bytes_rcvd
            metric_type: counter
          errorCount:
            alias: tomcat.error_count
            metric_type: counter
          requestCount:
            alias: tomcat.request_count
            metric_type: counter
          maxTime:
            alias: tomcat.max_time
            metric_type: gauge
          processingTime:
            alias: tomcat.processing_time
            metric_type: counter
    - include:
        j2eeType: Servlet
        attribute:
          processingTime:
            alias: tomcat.servlet.processing_time
            metric_type: counter
          errorCount:
            alias: tomcat.servlet.error_count
            metric_type: counter
          requestCount:
            alias: tomcat.servlet.request_count
            metric_type: counter
    - include:
        type: Cache
        accessCount:
          alias: tomcat.cache.access_count
          metric_type: counter
        hitsCounts:
          alias: tomcat.cache.hits_count
          metric_type: counter
    - include:
        type: JspMonitor
        jspCount:
          alias: tomcat.jsp.count
          metric_type: counter
        jspReloadCount:
          alias: tomcat.jsp.reload_count
          metric_type: counter

See the JMX Check documentation for a list of configuration options usable by all JMX-based checks. The page also describes how the Agent tags JMX metrics.

Restart the Agent to start sending Tomcat metrics to Datadog.

Configuration Options

  • user and password (Optional) - Username and password.
  • process_name_regex - (Optional) - Instead of specifying a host and port or jmx_url, the agent can connect using the attach api. This requires the JDK to be installed and the path to tools.jar to be set.
  • tools_jar_path - (Optional) - To be set when process_name_regex is set.
  • java_bin_path - (Optional) - Should be set if the agent cannot find your java executable.
  • java_options - (Optional) - Java JVM options
  • trust_store_path and trust_store_password - (Optional) - Should be set if ssl is enabled.

The conf parameter is a list of dictionaries. Only 2 keys are allowed in this dictionary:

  • include (mandatory): Dictionary of filters, any attribute that matches these filters will be collected unless it also matches the “exclude” filters (see below)
  • exclude (optional): Another dictionary of filters. Attributes that match these filters won’t be collected

For a given bean, metrics get tagged in the following manner:

mydomain:attr0=val0,attr1=val1

Your metric will be mydomain (or some variation depending on the attribute inside the bean) and have the tags attr0:val0, attr1:val1, domain:mydomain.

If you specify an alias in an include key that is formatted as camel case, it will be converted to snake case. For example, MyMetricName will be shown in Datadog as my_metric_name.

The attribute filter

The attribute filter can accept two types of values:

  • A dictionary whose keys are attributes names:

    conf: - include: attribute: maxThreads: alias: tomcat.threads.max metric_type: gauge currentThreadCount: alias: tomcat.threads.count metric_type: gauge bytesReceived: alias: tomcat.bytes_rcvd metric_type: counter

In that case you can specify an alias for the metric that will become the metric name in Datadog. You can also specify the metric type either a gauge or a counter. If you choose counter, a rate per second will be computed for this metric.

  • A list of attributes names:

    conf: - include: domain: org.apache.cassandra.db attribute: - BloomFilterDiskSpaceUsed - BloomFilterFalsePositives - BloomFilterFalseRatio - Capacity - CompressionRatio - CompletedTasks - ExceptionCount - Hits - RecentHitRate

In that case:

  • The metric type will be a gauge
  • The metric name will be jmx.[DOMAIN_NAME].[ATTRIBUTE_NAME]

Here is another filtering example:

instances:
  - host: 127.0.0.1
    name: jmx_instance
    port: 9999

init_config:
  conf:
    - include:
        bean: org.apache.cassandra.metrics:type=ClientRequest,scope=Write,name=Latency
        attribute:
          - OneMinuteRate
          - 75thPercentile
          - 95thPercentile
          - 99thPercentile

Note

List of filters is only supported in Datadog Agent > 5.3.0. If you are using an older version, please use singletons and multiple include statements instead.

# Datadog Agent > 5.3.0
  conf:
    - include:
        domain: domain_name
        bean:
          - first_bean_name
          - second_bean_name

# Older Datadog Agent versions
  conf:
    - include:
        domain: domain_name
        bean: first_bean_name
    - include:
        domain: domain_name
        bean: second_bean_name

Validation

Run the Agent’s info subcommand and look for tomcat under the Checks section:

  Checks
  ======
    [...]

    tomcat
    -------
      - instance #0 [OK]
      - Collected 26 metrics, 0 events & 0 service checks

    [...]

Compatibility

The tomcat check is compatible with all major platforms.

Data Collected

Metrics

tomcat.threads.max
(gauge)
The maximum number of allowed worker threads.
shown as thread
tomcat.threads.count
(gauge)
The number of threads managed by the thread pool.
shown as thread
tomcat.threads.busy
(gauge)
The number of threads that are in use.
shown as thread
tomcat.bytes_sent
(gauge)
Bytes per second sent by all the request processors.
shown as byte
tomcat.bytes_rcvd
(gauge)
Bytes per second received by all request processors.
shown as byte
tomcat.error_count
(gauge)
The number of errors per second on all request processors.
shown as error
tomcat.request_count
(gauge)
The number of requests per second across all request processors.
shown as request
tomcat.max_time
(gauge)
The longest request processing time (in milliseconds).
shown as millisecond
tomcat.processing_time
(gauge)
The sum of request processing times across all requests handled by the request processors (in milliseconds) per second.
shown as
tomcat.servlet.processing_time
(gauge)
The sum of request processing times across all requests to the servlet (in milliseconds) per second.
shown as
tomcat.servlet.error_count
(gauge)
The number of erroneous requests received by the servlet per second.
shown as error
tomcat.servlet.request_count
(gauge)
The number of requests received by the servlet per second.
shown as request
tomcat.cache.access_count
(gauge)
The number of accesses to the cache per second.
shown as get
tomcat.cache.hits_count
(gauge)
The number of cache hits per second.
shown as hit
tomcat.jsp.count
(gauge)
The number of JSPs per second that have been loaded in the web module.
shown as page
tomcat.jsp.reload_count
(gauge)
The number of JSPs per second that have been reloaded in the web module.
shown as page

Events

The Tomcat check does not include any event at this time.

Service Checks

The Tomcat check does not include any service check at this time.

Troubleshooting

Commands to view the metrics that are available:

The datadog-agent jmx command was added in version 4.1.0.

  • List attributes that match at least one of your instances configuration: sudo /etc/init.d/datadog-agent jmx list_matching_attributes
  • List attributes that do match one of your instances configuration but that are not being collected because it would exceed the number of metrics that can be collected: sudo /etc/init.d/datadog-agent jmx list_limited_attributes
  • List attributes that will actually be collected by your current instances configuration: sudo /etc/init.d/datadog-agent jmx list_collected_attributes
  • List attributes that don’t match any of your instances configuration: sudo /etc/init.d/datadog-agent jmx list_not_matching_attributes
  • List every attributes available that has a type supported by JMXFetch: sudo /etc/init.d/datadog-agent jmx list_everything
  • Start the collection of metrics based on your current configuration and display them in the console: sudo /etc/init.d/datadog-agent jmx collect

Further Reading