Red Hat Directory Server 7.1 Performance Tuning and Sizing Guidelines

Performance with different # of CPUs

operations / sec

14000

12000

10000

8000

6000

4000

2000

0

2

4

6

8

number of cpus

6 threads 8 threads

Figure 1: Performance difference based on different number of CPUs. Measured on Montecito-based test configuration @1.6GHz /CPUs.

Memory

The Red Hat Directory Server for HP-UX caches entry and indexing information in memory. It requires at least 256 MB of memory for a small deployment, but for large deployments, 512MB to 4GB or more RAM is needed for best performance. To estimate how much RAM is needed for Directory Server on a HP-UX Integrity system, please use the following formula:

Total_RHDS_RAM = 1.2 * (base_RAM_need_for_slapd_process + caches) Where

base_RAM_needed_for_slapd_process = 27 MB + nsslapd-threadnumber * 0.25MB caches = dbcache + SUM(all entry caches)* 2.3 + import_cache

Explanation:

•1.2: 20% additional RAM needed for slapd process to handle incoming LDAP operations. 20% is an estimated number, and it should be sufficient. However, testing is needed to ensure that it is enough before going into production.

•27MB: is the size of the slapd process.

•nsslapd-threadnumber *0.25 MB: each thread needs about 0.25 MB of memory.

•dbcache: specified as nsslapd-dbcachesize.

•All entry caches: specified as nsslapd-cachememsize. The 2.3 factor only needs to apply to the nsslapd-cachememsize of the databases you are doing the work with.

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