Assume that you have a SQL Service Broker (SSB) application deployed as part of Always On availability groups (AGs) in Microsoft SQL Server, and then you use AG listener to connect. After an AG failover, the SSB outgoing connections on the original primary replica are left open. This causes SSB incoming messages to be dropped because the databases are read-only or inaccessible.
Therefore, it manifests that SSB messages are stuck in the transmission queue, and more than one Service Broker connections exist in the AG.
Cumulative Update Information for SQL Server:
This issue is fixed in the following cumulative updates for SQL Server:
Note With this fix, SQL Server will close both incoming and outgoing SSB connections to the old primary Availability Group replica during failover, so that the messages which were getting dropped prior to this fix, will remain in the queue and they will get redirected to the new primary replica as soon as connections are established with the new primary replica, leaving no dropped or missing messages.
Service Pack Information for SQL Server:
This issue is fixed in the following service packs for SQL Server:
For more information about how to obtain the latest service pack, see How to obtain the latest service pack for SQL Server 2012
About Service packs for SQL Server
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.