Tomcat Monitor

You use Tomcat monitors to check metrics of your Tomcat servers.

Requirements

Add the following lines to the Tomcat startup script:

# You can add these lines anywhere in your startup script
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=8999
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false

For details on preparing Tomcat servers for testing, see Preparing Servers for Monitoring.

Monitor Settings

  • Port – The port used to communicate with the server.

  • User name – The user account ReadyAPI uses to connect to the server.

  • Password – The password used to connect to the server.

Frequently Used Metrics

The Tomcat monitor provides information about the load created by users on the application server. ReadyAPI displays the following statistics in charts by default:

  • VM Memory – Heap Memory Used – The current amount of memory used by a virtual machine. The large amount of used memory indicates heavy load or memory leaks.

  • VM Threading – Thread Count – The number of threads created on a virtual machine. Monitor this metric to get information about the number of created threads.

Here are some other frequently used metrics:

  • Thread Pool – Current Threads Busy – The percentage of busy threads on the server. Monitor these metrics to get the relative usage of the threads. This value should not exceed 80% in your soak and peak tests.

  • VM Garbage Collector – Collection Time – The garbage collector process has the highest priority in the system. If your machine spends a lot of time collecting garbage, it has fewer resources to work with incoming requests. Try to keep this value as low as possible.

Other Metrics

ReadyAPI Performance connects to Tomcat using JMX and exposes all available metrics. For a list of metrics created by the Tomcat community, see the Monitoring Tomcat page in the Tomcat documentation. Here is a list of metrics that ReadyAPI Performance can usually access:

Category

Description

Metrics

Cache

Information about the cache on the server. One set of statistics per directory.

Access Count

Cache Size

Hits Count

Data Source

Information about Data Source usage.

Num Active (%)

Max Active

Max Idle

Num Active

Num Idle

Request Processor

Information about the CPU usage. One set of statistics per server instance.

Error count (%)

Bytes Sent

Error Count

Max Time

Processing Time

Request Count

Session

Information about sessions run on the machine. One set of statistics per directory.

Rejected Sessions (%)

Active Sessions

Expired Sessions

Max Active

Rejected Sessions

Session Average Alive Time

Session Counter

Session Max Alive Time

Thread Pool

Information about threads on the machine. One set of statistics per server instance

Current Threads Busy (%)

Current Thread Count

Current Threads Busy

Max Threads

Operating System

Information about the computer running JVM.

Swap Space Total

Physical Memory Total

Virtual Memory Committed

Swap Space Free

System CPU Load

Physical Memory Free

VM Garbage Collector

Information about the garbage collector.

Collection Count

Collection Time

VM Memory

Information about memory usage on the virtual machine.

Heap Memory Used (%)

Heap Memory Committed

Heap Memory Max

Heap Memory Used

VM Threading

Information about threads on the virtual machine.

Total Started Thread Count

Daemon Thread Count

Peak Thread Count

Thread Count

See Also

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