HP-UX Directory Server 8.1 Performance Tuning and Sizing Guidelines

• Access log: The access log contains detailed information about client connections to the

directory. It provides beneficial troubleshooting information. Access logging is enabled by

default.

• Error log: The error log contains detailed messages about errors and events that the

directory experiences during normal operations. Error logging is enabled by default.

• Audit log: The audit log contains detailed information about changes made to each

database and to server configuration. By default, audit logging is disabled.

In a typical production environment, access log should be turned off; otherwise, it can cause

excessive disk I/O that affects performance — even with buffering. For improved directory server

performance, HP recommends hosting the access log file on a lightly-loaded disk.

In the performance test environment, turning off the access log yielded an increase in the search

throughput rate by 4%. For test results, see Table 6.

Performance measurements

This section describes performance testing for HP-UX Directory Server version 8.1 under a controlled

environment with databases containing 100, 10K, 100K, 250K, 500K and 1M entries. The directory

entries were inetorgPerson entries generated by the dbgen script (located in the

/opt/dirsrv/bin directory on a system installed with HPDS 8.1). Performance data was

measured for exact search on cn only.

Purpose

• Find out how the number of CPUs affects the performance.

• Find out how thread numbers (nsslapd-threadnumber) affects the performance.

• Find out how the dbcache size (nsslapd-dbcachesize) affects the performance.

• Find out how the cache size in terms of memory (nsslapd-cachememsize) and the cache

size in terms of entries it can hold (nsslapd-cachesize) affect the performance.

• Find out how logging affects the performance.

• Find out the performance differences between a SSL connection and a non-SSL connection.

Test results

Data collection 1: (Different number of CPUs)

This set of data is collected to show the performance differences resulting from different numbers of

CPUs, as measured on the Montvale-based test configuration @1.66GHz /CPUs.

• # of entries: 500k entries

• 128 client threads

• HPDS parameter settings: nslapd-dbcachesize and nslapd-cachememsize are big

enough to cache all the entries, and nsslapd-threadnumber is set to 6.

From Table 1, we can see that as the number of CPUs doubles, the performance nearly doubles.

Table 1: HPDS 8.1 performance in relation to numbers of CPUs

Server Searches per

second

Montvale-based test configuration 1 CPU (2 cores) @1.6GHz 9471.60

Montvale-based test configuration 2 CPUs (4 cores) @1.6GHz 18650.35