Apache Tomcat

StackState curated integration

Overview

This check collects Tomcat metrics, for example:

  • 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 Agent V2 StackPack, 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
attribute:
accessCount:
alias: tomcat.cache.access_count
metric_type: counter
hitsCounts:
alias: tomcat.cache.hits_count
metric_type: counter
- include:
type: JspMonitor
attribute:
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 StackState.

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 StackState 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 StackState. 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
conf:
- include:
domain: domain_name
bean:
- first_bean_name
- second_bean_name

Log Collection

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.

  • Collecting logs is disabled by default in the StackState Agent, enable it in your stackstate.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])
  • Change the path and service parameter values and configure them for your environment. See the sample tomcat.yaml for all available configuration options.

  • Restart the Agent.

Validation

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

Data Collected

Metrics

See metadata.csv for a list of metrics provided by this check.

Events

The Tomcat check does not include any events.

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:

  • List attributes that match at least one of your instance configurations:

    sudo /etc/init.d/stackstate-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/stackstate-agent jmx list_limited_attributes

  • List attributes that are actually collected by your current instance configurations:

    sudo /etc/init.d/stackstate-agent jmx list_collected_attributes

  • List attributes that don't match any of your instance configurations:

    sudo /etc/init.d/stackstate-agent jmx list_not_matching_attributes

  • List every attribute available that has a type supported by JMXFetch:

    sudo /etc/init.d/stackstate-agent jmx list_everything

  • Start the collection of metrics based on your current configuration and display them in the console:

    sudo /etc/init.d/stackstate-agent jmx collect