| The wait type HADR_CLUSAPI_CALL is ranked #54 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. SQL Server HADR_CLUSAPI_CALL wait types are a type of wait that occurs when a user request is waiting for a response from the Windows Server Failover Clustering (WSFC) API. This type of wait is typically associated with Always On Availability Groups, which is a feature of SQL Server that provides high availability and disaster recovery for your databases. When a user request is made to an availability group, the SQL Server engine will first check if the request can be serviced by the local primary replica. If the local primary replica is not able to process the request, the request will be forwarded to the Windows Server Failover Clustering API for further processing. This is where the HADR_CLUSAPI_CALL wait type comes into play. While a user request is waiting for a response from the WSFC API, it will be in a HADR_CLUSAPI_CALL wait state. This means that the request is not actively being processed, but it is not lost or discarded either. Instead, it is waiting for the WSFC API to provide a response so that it can be processed by the appropriate availability replica. The HADR_CLUSAPI_CALL wait type is typically a benign wait type and is not something to be concerned about. However, if you notice that your SQL Server is experiencing a high number of HADR_CLUSAPI_CALL waits, it could indicate a performance issue with your availability group. In this case, it may be worth investigating further to determine the cause of the issue and take appropriate action to resolve it. Overall, SQL Server HADR_CLUSAPI_CALL wait types are a normal part of the operation of Always On Availability Groups and do not typically indicate a problem. However, if you notice a high number of these waits, it could be worth investigating to ensure that your availability group is performing optimally. Applies toRelated WaitsHADR_AG_MUTEXHADR_AR_CRITICAL_SECTION_ENTRY HADR_AR_MANAGER_MUTEX HADR_AR_UNLOAD_COMPLETED HADR_ARCONTROLLER_NOTIFICATIONS_SUBSCRIBER_LIST HADR_BACKUP_BULK_LOCK HADR_BACKUP_QUEUE HADR_COMPRESSED_CACHE_SYNC HADR_CONNECTIVITY_INFO HADR_DATABASE_FLOW_CONTROL HADR_DATABASE_VERSIONING_STATE HADR_DATABASE_WAIT_FOR_RESTART HADR_DATABASE_WAIT_FOR_TRANSITION_TO_VERSIONING HADR_DB_COMMAND HADR_DB_OP_COMPLETION_SYNC HADR_DB_OP_START_SYNC HADR_DBR_SUBSCRIBER HADR_DBR_SUBSCRIBER_FILTER_LIST HADR_DBSEEDING HADR_DBSEEDING_LIST HADR_DBSTATECHANGE_SYNC HADR_FABRIC_CALLBACK HADR_FILESTREAM_BLOCK_FLUSH HADR_FILESTREAM_FILE_CLOSE HADR_FILESTREAM_FILE_REQUEST HADR_FILESTREAM_IOMGR HADR_FILESTREAM_MANAGER HADR_GROUP_COMMIT HADR_LOGCAPTURE_SYNC HADR_LOGCAPTURE_WAIT HADR_LOGPROGRESS_SYNC HADR_NOTIFICATION_DEQUEUE HADR_NOTIFICATION_WORKER_EXCLUSIVE_ACCESS HADR_NOTIFICATION_WORKER_STARTUP_SYNC HADR_NOTIFICATION_WORKER_TERMINATION_SYNC HADR_PARTNER_SYNC HADR_READ_ALL_NETWORKS HADR_RECOVERY_WAIT_FOR_CONNECTION HADR_RECOVERY_WAIT_FOR_UNDO HADR_REPLICAINFO_SYNC HADR_SYNC_COMMIT HADR_SYNCHRONIZING_THROTTLE HADR_TDS_LISTENER_SYNC HADR_TDS_LISTENER_SYNC_PROCESSING HADR_TIMER_TASK HADR_TRANSPORT_DBRLIST HADR_TRANSPORT_FLOW_CONTROL HADR_TRANSPORT_SESSION HADR_WORK_POOL HADR_WORK_QUEUE HADR_XRF_STACK_ACCESS See AlsoAll Wait Types |  |