Monitoring Cube Performance and Usage - Expert Cube Development with SSAS Multidimensional Models - page 327

• Committed Bytes : This is the amount of virtual memory requested by all

running processes. If this value is higher than the amount of available physical
RAM, data has been paged to disk. However, if the Pages/sec rate is low or
null, data paged to disk is not used often. As long as it does not need to be
accessed, there will be no performance problems caused by this situation.

• % Committed Bytes in Use : This is the ratio of Committed Bytes to Commit

Limit , which is the maximum amount of virtual memory that can be
allocated (a value slightly below the sum of physical RAM and paging file).

A second group is made up of performance counters that are available for any
running process. This group is included in the Process category and includes a few
counters that we have already seen in Task Manager, as well as other counters that
are useful for analyzing the state of an Analysis Services instance, as shown:

• Virtual Bytes : This is generally not so useful, because it represents the

amount of virtual memory used for both private allocations and file mapping
(including executable files).

• Page File Bytes and Private Bytes : These are usually very similar for

Analysis Services, and correspond to the Commit Size counter we have seen
in Task Manager.

• Page File Bytes Peak : This is very important because it reports the maximum

value reached by Page File Bytes since the start of process execution,
regardless of when we started monitoring. If this value is higher than Page
File Bytes , there has been a reduction in the amount of memory requested by
Analysis Services, but since this peak has been reached earlier, this usually
implies that it could be reached again in the future.

• Working Set : This corresponds to the Working Set (Memory) value in

Task Manager

• Working Set—Private : This corresponds to the Memory (Private Working

Set) value in Task Manager

• Working Set Peak : This is the maximum value reached by Working Set since

the start of process execution, regardless of when we started monitoring. This
value can be higher than the actual Working Set counter, because even if a
process has not released memory previously allocated, part of that memory
may have been paged as a result of memory activity by other processes.
If this happens with Analysis Services, we could investigate which other
processes are requesting memory concurrently on the same server.