HP-UX Directory Server 8.1 Performance Tuning and Sizing Guidelines

nsslapd-threadnumber is set to 6 or 8 (on a Montvale-based test bed with 8 CPUs). Based on the

performance test experiment, the best exact search performance occurs only when nsslapd-

threadnumber is tuned close to the number of CPUs. This performance characteristic is verified with

up to 8 CPUs on a Montvale-based test bed.

When tuning this parameter, consider the following:

• If the directory only serves non-SSL based search requests, tune nsslapd-threadnmber

starting from where it equals the number of CPUs.

• If the directory needs to handle time-consuming operations that require threads to be blocked

for a long time, such as SSL based searches, then tune up the nsslapd-threadnumber.

• If a large number of clients are concurrently requesting connections, tune up the nsslapd-

threadnumber.

• If you experience low CPU utilization under a heavy load, or slow response time, try to tune

up nsslapd-threadnumber and see if performance improves.

Figure 1: Performance based on nsslapd-threadnumber

nsslapd-dbcachesize

The nsslapd-dbcachesize parameter is described as follows in the

HP-UX Directory Server

configuration, command, and file reference:

nsslapd-dbcachesize

This performance tuning attribute specifies the database index cache size. It is one of

the most important values for controlling how much physical RAM the directory server uses.

This is not the entry cache. This is the amount of memory the Berkeley database backend will

use to cache the indexes (the .db4 files) and other files. This value is passed to the Berkeley

DB API function set_cachesize. If automatic cache resizing is activated, this attribute is

5000

10000

15000

20000

25000

0 20 40 60 80 100 120 140

operations/sec

number of threads

2 dual-core CPUs