The replica tools-db-2 is currently lagging 18 hours behind the primary tools-db-1 (Grafana chart). This is (correctly) triggering the alert ToolsToolsDBReplicationLagIsTooHigh.
SHOW SLAVE STATUS\g in the replica shows the replication is active, but it's taking hours to process a single transaction.
This happened before (T341891 and T338031). Both times the replica caught up after a couple of days, without any intervention. I will check if the database causing this issue is the same or a new one.