HADR_TDS_LISTENER_SYNC_PROCESSING SQL Server Wait Type

Wait Type HADR_TDS_LISTENER_SYNC_PROCESSING

The wait type HADR_TDS_LISTENER_SYNC_PROCESSING is ranked #312 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 Always On Availability Groups use a listener to handle client connections and route them to the appropriate replica. Occasionally, tasks associated with managing this listener can introduce wait types like HADR_TDS_LISTENER_SYNC_PROCESSING. Understanding this wait type can help you troubleshoot and optimize your Always On setup for better client connectivity and system performance.

What is HADR_TDS_LISTENER_SYNC_PROCESSING?

The HADR_TDS_LISTENER_SYNC_PROCESSING wait type occurs when SQL Server is processing tasks related to synchronizing the listener for Always On Availability Groups. This includes managing routing rules, handling failovers, and ensuring that client connections are directed to the correct replica.

In simpler terms, this wait type shows that SQL Server is performing background work to keep the listener synchronized and functioning properly. Some occurrence of this wait type is expected during normal operations, but excessive or prolonged waits may indicate underlying issues that need attention.

Why Does HADR_TDS_LISTENER_SYNC_PROCESSING Happen?

Several factors can contribute to HADR_TDS_LISTENER_SYNC_PROCESSING waits, including:

  • High volumes of client connection requests, especially during peak traffic periods.
  • Frequent failovers or changes in the availability group configuration.
  • Network latency or insufficient bandwidth between the listener and replicas.
  • Resource bottlenecks, such as limited CPU or memory on the server hosting the listener.
  • Suboptimal configuration of routing rules or listener settings.

Identifying and addressing these factors can help reduce the occurrence of this wait type and improve overall performance.

How to Monitor HADR_TDS_LISTENER_SYNC_PROCESSING Waits

Monitoring HADR_TDS_LISTENER_SYNC_PROCESSING waits is crucial for identifying patterns and diagnosing issues. The Database Health Monitor is a powerful tool for tracking these waits. Its Historic Waits Monitoring feature enables you to observe when these waits occur, how often they happen, and their impact on system performance.

By using Database Health Monitor, you can pinpoint whether these waits are linked to high connection volumes, network issues, or resource constraints and take targeted actions to resolve them.

What Can You Do About HADR_TDS_LISTENER_SYNC_PROCESSING Waits?

If you experience frequent or prolonged HADR_TDS_LISTENER_SYNC_PROCESSING waits, consider these actions:

  • Ensure your network infrastructure has adequate bandwidth and low latency to support listener synchronization tasks.
  • Allocate sufficient CPU and memory resources to the servers managing the Always On listener.
  • Optimize routing rules to reduce the processing overhead for client connection management.
  • Distribute workloads more evenly across replicas to prevent overloading any single node.
  • Schedule maintenance and failover operations during off-peak hours to minimize their impact on the listener.

These steps can help reduce listener synchronization delays and improve overall system performance and client connectivity.

Why Use Database Health Monitor?

The Database Health Monitor is an essential tool for tracking SQL Server wait types, including HADR_TDS_LISTENER_SYNC_PROCESSING. Its Historic Waits Monitoring feature provides actionable insights into wait trends, helping you identify and address bottlenecks. With Database Health Monitor, you can ensure that your Always On Availability Groups and listener services operate smoothly and efficiently.

Start using Database Health Monitor today to monitor and optimize your SQL Server’s performance, ensuring a resilient and high-performing database system!


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Applies to

    Related Waits

    HADR_AG_MUTEX
    HADR_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_CLUSAPI_CALL
    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_TIMER_TASK
    HADR_TRANSPORT_DBRLIST
    HADR_TRANSPORT_FLOW_CONTROL
    HADR_TRANSPORT_SESSION
    HADR_WORK_POOL
    HADR_WORK_QUEUE
    HADR_XRF_STACK_ACCESS

    See Also


    All Wait Types
    HADR_TDS_LISTENER_SYNC_PROCESSING SQL Server Wait Type