Why CHECKDB Repair Invalidates Replication

Paul Randal explains why running DBCC CHECKDB on a published article will cause subscriptions to become invalidated:

Whenever I’m teaching and recovering from corruption, I always stress that if the REPAIR_ALLOW_DATA_LOSS option of DBCC CHECKDB (which I’ll just call ‘repair’ from now on) has to be used, you should do the following:

  • Run another DBCC CHECKDB to make sure that repair fixed everything and no new problems were exposed (by the repair fixing something that was blocking DBCC CHECKDB‘s access to a portion of the database)
  • Run DBCC CHECKCONSTRAINTS on any tables or indexes that were repaired and are involved in constraints (stated in Books Online too)
  • Reinitialize any replication subscriptions that are based on tables that were repaired (stated in Books Online too)
  • Reevaluate your HA/DR strategy so you don’t have to use repair again in future

One question I’m often asked is about why replication can be broken by running repair.

Read on for the answer.

Related Posts

Kafka and MirrorMaker

Renu Tewari describes what MirrorMaker does for Kafka today and what is coming with version 2: Apache Kafka has become an essential component of enterprise data pipelines and is used for tracking clickstream event data, collecting logs, gathering metrics, and being the enterprise data bus in a microservices based architectures. Kafka is essentially a highly […]

Read More

Conflict Tracking in Merge Replication

Ranga Babu shows the two different models for conflict detection with merge replication: Conflict Detection:The conflict detection depends on the type of tracking we configure for the article.– Row-level tracking: If data changes are made to any column on the same row at both ends, then it is considered a conflict.–Column-level tracking: If data changes are made […]

Read More

Categories

April 2018
MTWTFSS
« Mar May »
 1
2345678
9101112131415
16171819202122
23242526272829
30