This document describes how to create a heap and threaddump from a java OX App Suite Middleware service running inside the Kubernetes cluster.

Prerequisites

• An active shell to a running Toolkit Container within the cluster. See Starting.

Commands

To create a heap and thread dump from a running OX App Suite Middleware process, use the mwctl debug tool with its heapdump and threaddump subcommands.

Heap dump

Create a Heap Dump

Creating a heap dump on the target system:

 mwctl debug heapdump <POD>

By default, the heap dump is written and compressed to the /tmp directory on the Middleware container's file system. For example.: /tmp/heapdump_1720008357.hprof.tar.gz.

Download a Heap Dump

You can also use the --download flag if you prefer to transfer the heap dump to the Toolkit Container for further processing.

 mwctl debug heapdump --download <POD>

This will download the created heap dump to the Toolkit Container and place it into your current working directory.

To transfer the heap dump to your local computer, you can use a standard kubectl cp command. For example:

kubectl cp -n <NAMESPACE> <POD>:<FILENAME> --retries 20

Heap Dump Options

By default, mwctl heapdump creates a full memory dump containing the complete heap of the process (analogous to jmap’s -dump:all option). Alternatively, you can generate a dump of only live objects by specifying the --dumptype live option, which triggers a garbage collection before the heap dump is taken.

 mwctl debug heapdump --dumptype live <POD>

Further information

Refer to "debug heapdump" for a detailed explanation and a list of all available options.

Thread dump

Create a Thread Dump

To create a thread dump from a running OX App Suite Middleware process, use the mwctl tool with its debug and heapdump subcommands.

mwctl debug threaddump -s <POD>

This command creates a single (-s) thread dump from the OX App Suite Middleware process on the specified pod and prints it to your terminal.

Create a comprehensive Thread Dump

Instead of generating a single thread dump, the command can also create more comprehensive dumps, including multiple single dumps and top(1) outputs.

mwctl debug threaddump <POD>

This command will create five separate thread dumps and a top(1) output, each saved in a separate file that will be downloaded into current working directory of the Toolkit Container afterward. For example.: ./threaddumps_1720011630/

To transfer a thread dump file to your local computer, you can use a standard kubectl cp command. For example:

kubectl cp -n <NAMESPACE> <POD>:<FILENAME> --retries 20

Further information

Refer to "debug threaddump" for a detailed explanation and a list of all available options.