Wednesday, October 25, 2017


Shared Memory Protocol is not Supported on SQL Server Failover Clusters

I was recently trying to work out why SSAS installed on the same server as SQL Server would not use shared memory for its processing connections. It may be obvious to some people, but an internet search turns up surprising few references: the Shared Memory Protocol is not Supported on SQL Server Failover Clusters.

On a standard SQL Server instance, the Shared Memory protocol can be used when a client is running on the same computer as the SQL Server instance and the Shared Memory Protocol is enabled in SQL Server’s network protocols. (You can check the status of the enabled protocols using SQL Server Configuration Manager).

sys.dm_exec_connections will show you which net transport a client connection is using:

SELECT net_transport FROM sys.dm_exec_connections WHERE session_id = @@SPID;

You can force a client connection to use a specific protocol by prefixing the Server name in the connection string with one of these modifiers:

  • TCP: tcp:
  • Multiprotocol = rpc:
  • Shared Memory = lpc:

e.g. Force connection to use the TCP protocol:


In addition, you can force the client connection to use the Shared Memory protocol by using (local) as the server name. You can also use localhost or a period (.) e.g.:



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