Enterprise Library Test Guide - Willy .Net

Testing for Performance and Scalability 223
Area Performance counter name Threshold
Memory Pool Nonpaged Bytes This is the number of bytes in
the nonpaged pool, an area
of system memory for objects
that cannot be written to disk,
but must remain in physical
memory as long as they are
allocated. This value should
remain stable during stress
tests.
Memory Committed Bytes This value is the amount of
virtual memory that is supplied
either by RAM or by a
secondary storage device.
You can use it to calculate
the contention index. This
index is the ratio of CommittedBytes/Total
RAM. This
ratio should be less that 2:1.
Higher ratios mean that there
is too much paging. The only
scenario where a larger ratio
is acceptable is when the
Caching Application Block
adds unique keys to the cache
without using any scavenging
or expiration policies.
Memory Pages/sec This value should be zero. It
represents hard page faults,
which indicates that there is
memory starvation because of
a memory leak.
Memory Available MBytes This value should be stable
during the stress tests. Low
values for SQL Server is
normal because it allocates
as much memory as it can for
caching. In general, the value
should be at least 20 MB for
IIS when it hosts Enterprise
Library. The exception is when
the Caching Application Block
adds unique keys to the cache
without using scavenging or
expiration policies. In this
case, the value is dependent
on the number of items you
add to the cache.
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