Generating a core dump file for px-runtime image

You can generate a core dump file for your px-runtime image when a DataStage job fails. A core dump registers the state of a job and the status of working memory at the moment a job unexpectedly stops.

About this task

This procedure describes how to generate a core dump and get a core stack trace for failing processes in Red Hat OpenShift pods.

Procedure

Set the kernel.core_pattern parameter to enable core dump generation:
1. Log in to a Kubernetes worker node as the root user with the following command.
```
oc debug node/<node-name>
```
2. Check the current kernel.core_pattern with the following command.
```
cat /proc/sys/kernel/core_pattern
```
3. Set the core_pattern in the DataStage pod.
```
sysctl -w kernel.core_pattern=/var/tmp/core-%e-sig%s-user%u-group%g-pid%p-time%t
```
4. Repeat the steps for the worker nodes that host the pods.
In your DataStage job, go to Job Properties > Environment Variables section, and set the following environment variables:
- APT_NO_PM_SIGNAL_HANDLERS to 1
- APT_DUMP_SCORE to TRUE
- APT_PM_SHOW_PIDS to TRUE
Install the gdb debugger program in the pods:
1. Open a shell on the pod where you want to run the gdb debugger. Here, ds-px-default-ibm-datastage-px-runtime-58d4458bf5-nb68s is an example name of the px-runtime instance.
```
oc rsh ds-px-default-ibm-datastage-px-runtime-58d4458bf5-nb68s
```
2. Open the public repository and download the getstacks.tar.gz file.
```
sh-5.1$ cd /tmp
sh-5.1$ curl -LJO https://github.com/IBM/DataStage/raw/refs/heads/main/utils/getstacks/getstacks.tar.gz
```
3. Decompress the downloaded utility tar. file.
```
sh-5.1$ tar xvfz getstacks.tar.gz
gdb-8.2.1-x86_64.tar.gz
getstacksre.sh
getstackscpd.sh
```
4. Decompress the gdb binaries and run the gdb program.
```
sh-5.1$ tar xvfz gdb-8.2.1-x86_64.tar.gz
gdb
gstack
sh-5.1$ ./gdb
```
After you generate a core dump, you can collect the core stack trace.
Collect the core stack trace:
1. Log in to the pod.
2. Locate the core file.
```
ls <dir-in-the-core_pattern>
```
3. Start the gdb program and collect the stack trace.
  For example, /opt/ibm/PXService/Server/PXEngine/bin/osh is an executable application that creates the core file, and core.1234 is a core dump file of the application at the time of the crash.
```
/tmp/gdb /opt/ibm/PXService/Server/PXEngine/bin/osh core.1234
```
4. In the gdb, run the following commands independently.
```
bt
```
```
thread apply all bt
```
```
info sharedlibrary
```
```
quit
```
5. Repeat the steps for all DataStage pods.