SSAS and SQL Engine Memory

Sam 2015-04-08 20:21:03

How is memory managed in an enviornment if both SSAS and SQL Server Engine coexist ? Would setting the SQL MaximumServerMemory to 85% of the memory limits the available memory that the SSAS can utilize to the remaining 15% ? the SSAS memory configuration is set to default
SQL_Steve 2015-04-09 15:18:07
Sam,
SSAS and SQL don't consider other services when applying limits. SSAS uses memory limits based on the total memory on the server. SSAS defaults to a high memory limit of 80% of the total server memory. When you have both engines sharing that memory you will likely want to adjust the limits for each engine. See more details in Greg Gonzalez' post on Analysis Services Memory Limits.
Sam 2015-04-09 18:34:52
Thanks Steve,

Based on the post, if SSAS requires additional memory, the Windows memory managment will signal the SQL buffer pool to release memory back to the OS and then allocate that to SSAS. Is releasing memory from SQL to OS and allocating it to SSAS a CPU intensive operation by any chance (MinServerMemory is set to zero) ?

The reason I am asking is that I have increased the MaxServerMemory on the SQL server from 40% to 85% of the available memory in the server in both DEV and PROD environments and since then, the performance is impacted and I see high CPU utilization associated on SSAS processes in both enviornments. This could possibly be a bug in the applicaiton, but, I do want to rule out the memory configuraion change.