How To Take A Heap Dump On A Container Gateway Install

Products

• CA API Gateway

Issue/Introduction

How to take a heap dump on a container gateway install and how to run our DCT tool on a container gateway.

Environment

Release : 10.1

Component : CA API GATEWAY

Resolution

Generating a Heap dump is not officially available via DCT for docker but with our 10.1 image it can be captured with the jcmd within the java_home directory of the docker image.

Enter directly into the gateway pod and then determine the gateway pid.

$ docker exec -it -u 0 GatewayContainerID /bin/bash

# /usr/lib/jvm/default-jvm/jcmd/bin/jcmd GatewayPID GC.heap_dump /tmp/dump.hprof
8:
Dumping heap to /tmp/dump.hprof ...

 

Regarding the DCT tool:

To run it

kubectl exec <your pod> "/usr/dct/collect.sh -m gateway -f <your dct output location>" 
example : kubectl exec -n Namespace PodName -- /usr/dct/collect.sh -a -f /tmp

To download it 

c:\>kubectl cp gw-dcnew-858ff48757-t5zrd:/tmp/ Temp
tar: Removing leading `/' from member names
tar: /tmp/.java_pid7: socket ignored

To connect to container 
kubectl exec --stdin --tty PodName -- /bin/bash

Additional Information

kubectl exec --stdin --tty <podId> -n <namespace> -- /bin/bash                                                            # logged into container Shell

ps awwx | grep Gateway.jar                                                                                                                          # To get ProcessID

/usr/lib/jvm/default-jvm/jcmd/bin/jcmd <GwyProcessId> GC.heap_dump /tmp/dump.hprof           # Generate heap dump

 

Exit Container Shell

 

kubectl cp -n <namesspace> <podId>:/tmp/ .                                                                                            # Copy heap dump from Container to Client machine.