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Scheduler

Crunchy Scheduler

The Crunchy Scheduler container implements a cronlike microservice within a namespace to automate backups of a PostgreSQL database.

Currently Crunchy Scheduler only supports two types of tasks:

  • pgBackRest
  • pgBaseBackup

This service watches Kubernetes for config maps with the label crunchy-scheduler=true. If found the scheduler will parse the data found in the config map (json object) and convert it to a scheduled task. If the config map is removed, the scheduler will delete the task.

See the following examples for creating config maps that Crunchy Scheduler can parse:

The Crunchy Scheduler requires a Service Account to create jobs (pgBaseBackup) and to exec (pgBackRest). See the scheduler example for the required permissions on this account.

Crunchy Scheduler uses the UTC timezone for all schedules.

pgBackRest Schedules

To configure Crunchy Scheduler to create pgBackRest backups the following is required:

  • pgBackRest schedule definition requires a deployment name. The PostgreSQL pod should be created by a deployment.

pgBaseBackup Schedules

To configure Crunchy Scheduler to create pgBaseBackup scheduled backups, the following is required:

  • The name of the secret that contains the username and password the Scheduler will use to configure the job template. See the primary secret example for the structure required by the Scheduler.
  • The name of the PVC created for the backups. This should be created by the user prior to scheduling the task.

When using pgBaseBackup schedules, it may be required to apply specific supplementalGroups or an fsGroup to the backup job created by the scheduler. To apply a specific securityContext for your storage provider, mount a backup-template.json to /configs on the scheduler pod.

For an example of applying a custom template, see the scheduler example.

Kubernetes and OpenShift

First, start the PostgreSQL example created for the Scheduler by running the following commands:

# Kubernetes
cd $CCPROOT/examples/kube/scheduler/primary
./run.sh

The pod created should show a ready status before proceeding.

Next, start the scheduler by running the following command:

# Kubernetes
cd $CCPROOT/examples/kube/scheduler
./run.sh

Once the scheduler is deployed, register the backup tasks by running the following command:

# Kubernetes
cd $CCPROOT/examples/kube/scheduler
./add-schedules.sh

The scheduled tasks will (these are just for fast results, not recommended for production):

  • take a backup every minute using pgBaseBackup
  • take a full pgBackRest backup every even minute
  • take a diff pgBackRest backup every odd minute

View the logs for the scheduler pod until the tasks run:

${CCP_CLI?} logs scheduler -f

View the pgBaseBackup pods results after the backup completes:

${CCP_CLI?} logs <basebackup pod name>

View the pgBackRest backups via exec after the backup completes:

${CCP_CLI?} exec -ti <primary deployment pod name> -- pgbackrest info

Clean up the examples by running the following commands:

$CCPROOT/examples/kube/scheduler/primary/cleanup.sh
$CCPROOT/examples/kube/scheduler/cleanup.sh