JVM Monitoring Agent

Monitor JVM threads and save a threads dump when threads get blocked for given time.

Usage

Download the jar from https://github.com/toptal/jvm-monitoring-agent/releases

Add it to the command line of the application you wish to monitor:

java -javaagent:jvm-monitoring-agent-0.9.0.jar=threshold=1000,debug ...rest of command

Configuration flags/options

debug

Enables debugging output - in cases you suspect something is wrong it might provide additional information. To debug options problems make it first passed parameter.

path=...

Specifies where to save threads dumps.

interval=...

Specifies how often to check thread list for blocked threads. (Milliseconds)

threshold=...

Specifies how long thread needs to be blocked before dumps will be saved. (Milliseconds)

delay=...

Specifies delay between saving consecutive threads dumps. (Milliseconds)

filterRegex=...

Specifies a regular expression to filter known blocked threads. (Milliseconds)

Examples

Examples in examples/ are meant to check this library manually.

Check the agent does not interrupt exit.

rm tmp/*
ant && (cd examples/empty/ && ant) &&
java -javaagent:dist/jvm-monitoring-agent.jar -jar examples/empty/dist/empty.jar
ls -l tmp/

There should be no output from the execution.

Check the agent does find blocked threads.

rm tmp/*
ant && (cd examples/SynchronizedThreads/ && ant) &&
java -javaagent:dist/jvm-monitoring-agent.jar=debug,threshold=1000,delay=5000 -jar examples/SynchronizedThreads/dist/SynchronizedThreads.jar
ls -l tmp/

Execution is supposed to show arguments and times it took each second.

License

JVM Monitoring Agent is licensed under GNU Affero General Public License (GNU AGPLv3).