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Tomcat

Agent Check Agent Check

Supported OS: Linux Mac OS Windows

Tomcat Dashboard

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 included in the Datadog Agent package, so you don’t need to install anything else on your Tomcat servers.

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

Configuration

  1. Edit the tomcat.d/conf.yaml file, in the conf.d/ folder at the root of your Agent’s configuration directory to start collecting your Tomcat metrics and logs. See the sample tomcat.d/conf.yaml for all available configuration options.

  2. Restart the Agent

Metric Collection

  • Add this configuration block to your tomcat.yaml file to start gathering your Tomcat metrics:
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:

Option Required Description
user and password No Username and password
process_name_regex No 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 No Should be set when process_name_regex is set.
java_bin_path No Should be set if the agent cannot find your java executable.
java_options No Java JVM options
trust_store_path and trust_store_password No Should be set if com.sun.management.jmxremote.ssl is set to true on the target JVM.
key_store_path and key_store_password No Should be set if com.sun.management.jmxremote.ssl.need.client.auth is set to true on the target JVM.
rmi_registry_ssl No Should be set to true if com.sun.management.jmxremote.registry.ssl is set to true on the target JVM.

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

Key Required Description
include Yes A dictionary of filters. Any attribute that matches these filters are collected unless it also matches the “exclude” filters.
exclude No A 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 is mydomain (or some variation depending on the attribute inside the bean) and has the tags attr0:val0, attr1:val1, domain:mydomain.

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

See the sample tomcat.yaml for all available configuration options.

The attribute filter

The attribute filter accepts 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

For the case above, the metric aliases specified become the metric name in Datadog. Also, the metric type can be specified as a gauge or counter. If you choose counter, a rate per second is 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 is a gauge
  • The metric name is 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, 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

Log Collection

Available for Agent >6.0

Tomcat uses by default the log4j logger. To activate the logging into a file and customize the log format edit the log4j.properties file in the $CATALINA_BASE/lib directory as follows:

log4j.rootLogger = INFO, CATALINA

 # Define all the appenders
log4j.appender.CATALINA = org.apache.log4j.DailyRollingFileAppender
log4j.appender.CATALINA.File = /var/log/tomcat/catalina.log
log4j.appender.CATALINA.Append = true

 # Roll-over the log once per day
log4j.appender.CATALINA.layout = org.apache.log4j.PatternLayout
log4j.appender.CATALINA.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n

log4j.appender.LOCALHOST = org.apache.log4j.DailyRollingFileAppender
log4j.appender.LOCALHOST.File = /var/log/tomcat/localhost.log
log4j.appender.LOCALHOST.Append = true
log4j.appender.LOCALHOST.layout = org.apache.log4j.PatternLayout
log4j.appender.LOCALHOST.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n

log4j.appender.MANAGER = org.apache.log4j.DailyRollingFileAppender
log4j.appender.MANAGER.File = /var/log/tomcat/manager.log
log4j.appender.MANAGER.Append = true
log4j.appender.MANAGER.layout = org.apache.log4j.PatternLayout
log4j.appender.MANAGER.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n

log4j.appender.HOST-MANAGER = org.apache.log4j.DailyRollingFileAppender
log4j.appender.HOST-MANAGER.File = /var/log/tomcat/host-manager.log
log4j.appender.HOST-MANAGER.Append = true
log4j.appender.HOST-MANAGER.layout = org.apache.log4j.PatternLayout
log4j.appender.HOST-MANAGER.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n

log4j.appender.CONSOLE = org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout = org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss} %-5p [%t] %c{1}:%L - %m%n

 # Configure which loggers log to which appenders
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost] = INFO, LOCALHOST
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/manager] =\
  INFO, MANAGER
log4j.logger.org.apache.catalina.core.ContainerBase.[Catalina].[localhost].[/host-manager] =\
  INFO, HOST-MANAGER

Check Tomcat logging documentation for more information about Tomcat logging capabilities.

By default, Datadog’s integration pipeline support the following conversion patterns:

  %d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n
  %d [%t] %-5p %c - %m%n

Make sure you clone and edit the integration pipeline if you have a different format.

  • Collecting logs is disabled by default in the Datadog Agent, enable it in your datadog.yaml file with:
  logs_enabled: true
  • Add this configuration block to your tomcat.d/conf.yaml file to start collecting your Tomcat Logs:
  logs:
    - type: file
      path: /var/log/tomcat/*.log
      source: tomcat
      service: myapp
      #To handle multi line that starts with yyyy-mm-dd use the following pattern
      #log_processing_rules:
      #  - type: multi_line
      #    name: log_start_with_date
      #    pattern: \d{4}\-(0?[1-9]|1[012])\-(0?[1-9]|[12][0-9]|3[01])

Validation

Run the Agent’s status subcommand and look for tomcat under the Checks section.

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.
tomcat.servlet.processing_time
(gauge)
The sum of request processing times across all requests to the servlet (in milliseconds) per second.
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 events at this time.

Service Checks

tomcat.can_connect
Returns CRITICAL if the Agent is unable to connect to and collect metrics from the monitored Tomcat instance. Returns OK otherwise.

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 instance configurations: sudo /etc/init.d/datadog-agent jmx list_matching_attributes
  • List attributes that match one of your instance configurations but that are not 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 are actually collected by your current instance configurations: sudo /etc/init.d/datadog-agent jmx list_collected_attributes
  • List attributes that don’t match any of your instance configurations: sudo /etc/init.d/datadog-agent jmx list_not_matching_attributes
  • List every attribute 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


Mistake in the docs? Feel free to contribute!