•Tune the cache size big enough to fully utilize the cache. Two caches are available: database cache and entry cache. The database cache caches raw pages of the database files. The entry cache caches each entry that has been accessed in memory. For more information, see the “Tuning recommendations” section.

•Turn the access log off if you do not need it. Access log contains information for all the operations. By default, the access log is turned on.

•Tune the number of operation threads down for directory servers who mainly serve search requests. Although using fewer threads may give you better search performance, it may also become the bottleneck when the directory server also serves some time-consuming operations such as add or modify. For more information, see the “Tuning recommendations” section.

•Use indexes to speed up searches. However, HPDS provides the nsslapd- idlistscanlimit attribute to limit the number of IDs that are scanned per index key during a search operation. When the size of an individual ID list reaches this limit, the server will behave as if no index was available for that type of search. For more information about nsslapd-idlistscanlimit,see HP-UX Directory Server configuration, command, and file reference available at the following location: www.hp.com/go/hpux-security-docs (select HP-UX Directory Server)

•Disable unneeded plug-ins such as referential integrity, UID uniqueness, or schema checking, and so forth.

Other factors can also affect performance, such as whether SSL, replication, or referral is configured. Complex or many ACIs (directory server access control instructions) also affect performance. SSL performance data is also covered in the “Data collection 6: (SSL connection enabled compared to SSL connection disabled)” section.

Sizing and Tuning Recommendations

Sizing guidelines

Systems

HP-UX Directory Server can be hosted on any HP Integrity server that includes any member of the Intel® Itanium processor family that supports HP-UX 11i v3.

For producing this report, a Montvale-based HP Integrity Server is used. Both server and client systems are BL860c server blades with 8 GB of RAM, 2 dual core CPUs (Montvale 1.66GHz), and 60 GB hard drives. They are housed in an HP BladeSystem c7000 enclosure. The server and client systems are connected using a dedicated HP Procurve 2724 gigabit switch. The exact search throughput with this configuration (2 dual-core CPUs @ 1.66GHz, 8GB memory, and one 60 GB disk) can reach 6241.56 operations per second without tuning any directory server parameters.

All the data generated in the tests described in this paper is based on this specific hardware configuration.

CPUs

The HP-UX Directory Server will use multiple processors. When the number of processors increases, the performance improves, as shown in Table 1 in the “Data collection 1: (Different number of CPUs)” section. Under the performance test environment, changing the test machine configuration from 2 processor cores (1 CPU) to 4 processor cores (2 CPUs) can increase the performance throughput significantly. When configured correctly, the HP-UX Directory Server generally reaches the CPU limit before it reaches other constraints such as disk or networking I/O.

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