Configure Persistent Volumes for Logging

Add persistent volumes to retain transaction and debug logs when containers are restarted.

About this task

In a cloud native deployment, transaction and debug logs written to locations inside containers are deleted if a container is restarted. Persistent storage outside of the Kubernetes cluster is needed for logs to persist when containers are recreated.
Note: Configuration details for persistent volumes depend on site infrastructure details and can vary in specific deployments.

Procedure

  1. Update kubernetes/example-engine-config-sideloader/config/resource_create_config.info to add the following questions and answers.
    Note: Because all mtx-engine pods share the same template, it is important to specify the log directory name with local_%e_%c_%b.
    Do you want to use the default transaction log directory (y/n)?n
What directory do you want to use for the transaction log files?/myssd/local_%e_%c_%b
Do you want to use the default log directory (y/n)?n
What directory do you want to use for the log files?/myssd/local_%e_%c_%b
  2. Update kubernetes/example/engine/my_obj_templates/engine_sts.yaml to specify a hostPath volume. The configuration in the template must be different if you use another type of volume.
    Note: A hostPath volume uses a file or directory on the node to emulate network-attached storage. Use an NFS share or similar in a production environment.
    The comments # BEGIN_NEW_BLOCK and # END_NEW_BLOCK are added to clearly mark the boundary of new lines to be added. You do not have to add them in your file.
    apiVersion: apps/v1   
kind: StatefulSet   
metadata:   
  name: {name}   
spec:   
...
  template:
  ...
    spec:
      volumes:
      # BEGIN_NEW_BLOCK
      - name: ssd-logs
        hostPath:
          path: /mylogs
          type: DirectoryOrCreate
      # END_NEW_BLOCK
  ...
  containers:
  ...
    volumeMounts:
    # BEGIN_NEW_BLOCK
    - mountPath: /myssd
      name: ssd-logs
    # END_NEW_BLOCK
 ...

What to do next

Apply the configuration changes using the steps in the discussion about applying MATRIXX Engine configuration changes.