| The wait type FCB_REPLICA_WRITE is ranked #59 by Stedman Solutions and Database Health Monitor. Wait statistics, in the context of SQL Server, refer to the amount of time that a query spends waiting to access data in the database. When a client application requests data from the database, the request is placed in a queue and the client application must wait for its turn to access the data. The time that the query spends waiting is called a "wait" and is tracked by SQL Server. This information can be used to identify potential performance bottlenecks and optimize the performance of the database. Wait statistics are commonly used by database administrators to diagnose and troubleshoot performance issues in SQL Server. The SQL Server FCB_REPLICA_WRITE wait type is a type of wait that occurs when a session is waiting for a file control block (FCB) to be written to a replica. This type of wait is typically associated with database mirroring or Always On Availability Groups in SQL Server, where data changes on the primary replica are propagated to the secondary replicas. When a session is waiting on the FCB_REPLICA_WRITE wait type, it means that it is unable to proceed with its current operation until the FCB has been written to the replica. This can cause delays and slow down the overall performance of the SQL Server instance. To troubleshoot and resolve issues related to the FCB_REPLICA_WRITE wait type, it is important to first determine what operation is causing the wait and then investigate why that operation is taking a long time to complete. This may involve looking at the queries or processes that are executing the data changes on the primary replica, as well as the performance and availability of the secondary replicas. In some cases, it may be necessary to optimize the queries or processes that are causing the FCB_REPLICA_WRITE waits, or to adjust the workload on the SQL Server instance to reduce the occurrence of this wait type. It may also be necessary to adjust the settings of the database mirroring or Always On Availability Groups to improve their performance and reduce the need for FCB writes to the replicas. Overall, the FCB_REPLICA_WRITE wait type can be a useful indicator of potential performance issues related to database mirroring or Always On Availability Groups in SQL Server, and can help DBAs and developers identify and resolve those issues to improve the performance of their databases. Applies toRelated WaitsFCB_REPLICA_READSee AlsoAll Wait Types |  |