Wait Type BROKER_TRANSMISSION_TABLE

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 uses wait types to give insights into where delays might occur in processes. The BROKER_TRANSMISSION_TABLE wait type is associated with Service Broker, a SQL Server feature that supports messaging and asynchronous processing. This wait type occurs when SQL Server is working with the sys.transmission_queue, which holds messages waiting to be sent or processed. Understanding this wait type can help identify and address issues in Service Broker communication.

What Is the BROKER_TRANSMISSION_TABLE Wait Type?

The BROKER_TRANSMISSION_TABLE wait type appears when SQL Server is interacting with the sys.transmission_queue, a table that stores messages waiting to be transmitted or processed. This wait type can indicate that Service Broker tasks are encountering delays due to resource contention or other factors affecting the processing of queued messages.

When Does BROKER_TRANSMISSION_TABLE Appear?

This wait type typically occurs in the following scenarios:

• Message Backlogs – When a large number of messages are waiting in the transmission queue.
• Network Issues – If network latency or interruptions delay the delivery of messages to remote destinations.
• Service Broker Misconfigurations – Incorrect settings in Service Broker endpoints or routes can prevent messages from being processed efficiently.
• Resource Bottlenecks – Limited CPU, memory, or disk resources can slow down the processing of the transmission queue.
• Target Database Issues – If the target database or service is unavailable or under heavy load, messages may remain in the queue.

Why BROKER_TRANSMISSION_TABLE Waits Matter

While this wait type is normal in systems that rely on Service Broker, excessive or frequent waits may indicate potential issues. Common causes include:

• Unprocessed Messages – A buildup of messages in the transmission queue can delay new messages from being sent.
• Slow Disk Performance – Delays in writing to or reading from the transmission queue due to slow disk I/O.
• High Resource Usage – Resource contention on the server can slow the transmission queue processing.
• Communication Failures – Network issues or unavailable endpoints can prevent messages from leaving the queue.

How to Address BROKER_TRANSMISSION_TABLE Waits

If this wait type is causing delays or affecting performance, consider the following strategies:

• Monitor the Transmission Queue – Regularly check the sys.transmission_queue table for unprocessed messages and investigate the reasons for delays.
• Improve Network Performance – Use reliable, low-latency network connections to ensure timely message delivery.
• Optimize Resource Allocation – Ensure that sufficient CPU, memory, and disk resources are available for Service Broker operations.
• Validate Service Broker Configuration – Check endpoint and route settings to ensure they are correct and efficient for your workload.
• Address Target Database Issues – Ensure that target databases or services are available and can process incoming messages without delays.

Monitoring BROKER_TRANSMISSION_TABLE Waits

To track this wait type effectively, you can use the Historic Waits Monitoring feature in Database Health Monitor. This tool allows you to analyze wait statistics over time, helping you identify trends and diagnose bottlenecks in Service Broker communication. By monitoring waits, you can take proactive steps to optimize performance and ensure smooth message processing.

Stedman Solutions specializes in SQL Server performance tuning and Service Broker optimization. Whether you’re dealing with BROKER_TRANSMISSION_TABLE waits or other performance challenges, our Database Health Monitor provides powerful insights, and our managed services deliver expert support to keep your SQL Server running efficiently. Contact us today to learn how we can help improve your SQL Server performance and reliability.

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Applies to

Related Waits

See Also

• More About BROKER_TRANSMISSION_TABLE