Memory-Optimized Table Warnings

Robert Davis looks at messages in the error log related to memory-optimized tables:

The server on which we are running in-memory OLTP is a really hefty server with 128 logical cores and 1.5 TB of RAM (1.4 TB allocated to SQL Server). We are limiting in-memory’s memory usage with Resource Governor, which also makes it easy to see how much it is using. Needless to say, even with a limited percentage of 1.4 TB of RAM is still a lot of memory. The highest I have seen in-memory usage for this one database reach at peak activity levels is ~43 GB. In production, when the heavy in-memory OLTP processes complete, I see the system reclaim the in-memory buffers pretty quickly, though not completely. During a normal day, I often see the in-memory memory usage hovering between 1 and 3 GB even when there is virtually no traffic.

When testing in-memory on a dev server that only I was using before deploying to production, I noticed that the memory usage would stay at whatever high level it reached. This makes me believe that in-memory buffers are cleaned up and reclaimed as needed, and if not needed, they just hang around as in-memory buffers. And it appears that some of the buffers end up hanging around. Perhaps they wouldn’t if the server was memory starved. I have not tested that theory.

It’s a conjecture, but seems pretty solid.  Also worth reiterating is that they’re warnings, not errors.

Related Posts

Troubleshooting AG Creation Failure

Anthony Nocentino digs into logs to troubleshoot a failure when trying to create an Availability Group: Now we have some data to look through! When we look at the contents of the cluster logs, we’re totally on the other side of the spectrum when it comes to information verbosity. The logs so far have been […]

Read More

SQL Server Backup To Azure Tool Causing Restore Errors

Jack Li diagnoses an issue in which the Microsoft SQL Server Backup to Microsoft Azure Tool causes errors when trying to restore a database on an Azure VM with SQL Server 2008 R2: I worked on an interesting issue today where a user couldn’t restore a backup.   Here is what this customer did: backed up a […]

Read More


January 2017
« Dec Feb »