Spock Replication Issues

This page covers Spock replication issues.

Subscription Creation Fails

Symptom: The Spock subscription creation command fails with a connection or authentication error.

Solution: Test the connection from the local node to the remote node:

sudo -u postgres psql \
  "host=remote-node user=pgedge dbname=demo port=5432"

Verify that pg_hba.conf on the remote node allows connections from the local node and that the pgedge_user credentials match.

Subscriptions Not Syncing

Symptom: Subscriptions show as established but data does not replicate.

Solution: Query the subscription status:

sudo -u postgres psql -d demo \
  -c "SELECT * FROM spock.subscription;"

Check that the status column shows replicating for active subscriptions. Review the Postgres logs for replication-related errors and check for table constraint violations that may block replication.

Replication Lag Increasing

Symptom: Replication lag between nodes grows continuously.

Solution: Check subscription status and exception history:

sudo -u postgres psql -d demo \
  -c "SELECT * FROM spock.sub_show_status();"
sudo -u postgres psql -d demo \
  -c "SELECT * FROM spock.exception_status;"

Look for long-running transactions that block replication and verify that sufficient bandwidth exists between zones.

Subscription Shows Disabled State

Symptom: Spock marks a subscription as disabled and stops replicating.

Solution: Query the exception status to identify the root cause:

sudo -u postgres psql -d demo \
  -c "SELECT * FROM spock.exception_status;"

Resolve the underlying exception, then re-enable the subscription manually. Adjust the exception_behaviour parameter if automatic handling is not suitable.