Databases Reference
In-Depth Information
Scalability Optimizations
Scalability with respect to Analysis Services indicates how well Analysis Ser-
vices handles parameter value increases for dimension sizes, number of di-
mensions, size of the cube, number of databases, and number of concurrent
users — all of which affect server behavior. Analysis Services provides several
scalability parameters, such as handling a large number of partitions or a di-
mension with a large number of members (>5 million). In this section you will
learn about optimizations relevant specifically to scalability of Analysis Ser-
vices.
For Analysis Services 2005 you can control the number of queries executed
concurrently with the advanced configuration property
ThreadPool\Query\MaxThreads. The default value 10 works well for most
scenarios, but on a machine with many processors it should be increased, or
for scenarios combining short-running queries with long-running queries there
may be benefits from decreasing the value.
Configuring Server Configuration Properties
There are several configuration properties provided by Analysis Services with
which to fine tune the server. The default values for these properties have
been set for the most common scenarios. However for specific requirements
you might have change these settings to achieve the best performance from
Analysis Services. Microsoft recommends you change configuration settings
only when working with Microsoft product support. Documentation of all the
server configuration properties is expected to be released by Microsoft in
2006. Here we provide information on some of the configuration properties.
1. Memory\Total Memory Limit: The value for this property is between 0
and 100 since it is a percentage of the available memory. On a 4GB
memory machine if you have not enabled the /3GB switch the msmd-
srv.exe process will get 2 GB. Be aware that the total memory limit on
the server should be 80% of the available memory since Analysis Ser-
vices is expected to use the remaining 20%.
2. Memory\Low Memory Limit: Analysis Services contains a cleaner
thread which reclaims memory from jobs that are idle or have lower
priority. The cleaner thread constantly wakes up and reclaims memory
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