In Publication Properties the setting “Subscriptions never expire …” has a surprising effect on the job “Distribution clean up: distribution”.
This job removes orphaned and replicated transactions from the Distribution database once the retention period has expired.
However, “Subscriptions never expire …” stops this procedure from removing orphaned transactions – left by a deleted subscription – or for any other reason.
This results in the Distribution database growing and high CPU.
To fix this, allow subscriptions to be able to expire.
So failed subscriptions may be deleted if not fixed within a year. This preserves the robustness of “Subscriptions never expire”, whilst allowing orphaned transactions to be cleaned up.