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Is there always a huge redo queue in SQL Server?
SQL SERVER – Always On Secondary Replica Huge Redo Queue – Version Store is Full. New Version (s) Could Not be Added – SQL Authority with Pinal Dave SQL SERVER – Always On Secondary Replica Huge Redo Queue – Version Store is Full.
How to troubleshoot redo queue build up in AlwaysOn?
Troubleshooting REDO queue build-up (data latency issues) on AlwaysOn Readable Secondary Replicas using the WAIT_IN… Jan 15 2019 04:23 PM You have confirmed excessive build up of REDO queue on an AlwaysOn Availability Group secondary replica by one of the following methods:
Is there always on secondary replica huge redo queue?
SQL SERVER – Always On Secondary Replica Huge Redo Queue – Version Store is Full. New Version (s) Could Not be Added One of my earlier clients to whom I helped in configuration Always On Availability Group came back to me with strange behavior.
How to troubleshoot data latency in redo queue?
Click the Aggregation button: Add SUM for both duration and signal_duration and sort the aggregation by duration (SUM) in descending order. The resulting output shows the wait_types (with count of events in parentheses) and the aggregated sum of duration and signal duration – ordered by the highest wait_type duration in descending order:
How to add aggregation in redo queue build up?
The details now appear as columns in the table of events: Click the Grouping button to begin grouping the events – first by session_id and then by wait_type: Then after grouping by session_id and wait_type, you can add Aggregation. Click the Aggregation button:
Why is session _ ID still valid in redo queue?
To validate the session_id is still performing REDO on the database of interest (in case REDO threads were closed due to inactivity and re-started later.) For further investigation if there is evidence of scheduler contention – so that you know on which scheduler the REDO thread is executing.