How to profile memory of a spring boot webapp running on cloud foundry?

Question

I have a Spring boot application running on internal cloud foundry space. I want to monitor the Stack and Heap memory of this web app, in order to find a StackOverflow exception originating from code.

What could be the best way to profile the application.

Answer 1

• https://content.pivotal.io/blog/new-cloud-foundry-java-buildpack-improves-developer-diagnostic-tools
• https://community.pivotal.io/s/article/How-to-Remotely-Debug-Java-Applications-on-Cloud-Foundry

1. Run your app with JMX settings

• To test profiling on your local machine run theapp with the following JMX configuration and then go to the last step "3. VisualVM configuration" :

   java \\ -Dcom.sun.management.jmxremote=true \\ -Djava.rmi.server.hostname=localhost \\ -Dcom.sun.management.jmxremote.port=9999 \\ -Dcom.sun.management.jmxremote.rmi.port=9999 \\ -Dcom.sun.management.jmxremote.ssl=false \\ -Dcom.sun.management.jmxremote.authenticate=false \\ -jar theapp.jar ...

• To pass the JMX configuration to theapp in CF use the JBP_CONFIG_JMX environment variable (or JAVA_OPTS with params as above), manifest.yml :

   applications: - name: theapp buildpack: java_buildpack env: JBP_CONFIG_JMX: "{enabled: true, port: 9999}" # JAVA_OPTS: "-Dcom.sun.management.jmxremote=true -Djava.rmi.server.hostname=localhost -Dcom.sun.management.jmxremote.port=9999 -Dcom.sun.management.jmxremote.rmi.port=9999 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false"

2. Create SSH tunnel to theapp's container

cf ssh -N -T -L 9999:localhost:9999 theapp

3. VisualVM configuration

• Download VisualVM
• Run VisualVM: visualvm --jdkhome "$JAVA_HOME"
• Add JMX connection: localhost:9999

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You can also create SSH tunnel using PuTTY

• Retrieve and display theapp's guid:

   cf app theapp --guid # example: 12345678-1234-1234-1234-123456789012

• Get a one time password for ssh clients:

   cf ssh-code # example: PolSkAjEzyKtrUdnA

• Create PuTTY SSH connection:

  • hostname: theapp.your.cloud
  • port: 2222
  • username: cf:<app-guid>/<app-instance-index>@ssh.your.cloud
    • example: cf:12345678-1234-1234-1234-123456789012/0@ssh.your.cloud
  • password: <ssh-code>
    • example: PolSkAjEzyKtrUdnA
  • connection/ssh/tunnels/:
    • source port: 9999
    • destination: 127.0.0.1:9999

Answer 2

In case you have ssh access enabled in your cloudfoundry installation, you can use JMX or Yourkit Profiler to do this.

Here are some links:

• https://www.cloudfoundry.org/blog/just-released-java-buildpack-4-0/

• https://github.com/cloudfoundry/java-buildpack/blob/master/docs/framework-your_kit_profiler.md

• https://github.com/cloudfoundry/java-buildpack/blob/master/docs/framework-jmx.md