OpenLDAP Performance Tuning 8.0

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Article Information
This article applies to the following ZCS versions. ZCS 8.0

Zimbra OpenLDAP Server

As of 8.0.0, multiple master LDAP servers can be set up; these servers are authoritative for user information, server configuration, etc. Zimbra recommends having no more than 4 master servers deployed. Replica LDAP servers can be defined to improve performance and to reduce the load on the master servers. All updates are made to the master servers and these updates are then replicated to the replica servers.

See also the documentation on configuring Multiple Masters.

You may also wish to read over the entire set of keys available on the OpenLDAP Tuning Keys Wiki.

OpenLDAP Server Tuning

For best performance, the following settings should be modified. These settings apply to both the master LDAP server and the replica servers.

• Set the threads count to an appropriate level. The ZCS default is 8, which is fine for 1 or 2 CPU servers. The general rule of thumb is 4 threads for every real core.

zmlocalconfig -e ldap_common_threads=8

• Set the toolthreads count to an appropriate level. The ZCS default is 2. It should be set to 2. The purpose of the toolthreads setting is to decrease the amount of time it takes to slapadd a database.

zmlocalconfig -e ldap_common_toolthreads=2

If you have more than 100 domains, we suggest adjusting the following local config setting:

• ldap_cache_domain_maxsize. This sets the cache of the number of domains in the server. The default is 100. If more than 100 domains are configured, you should adjust this to the lower of the number of domains you have configured and 30,000. For example, with 45,000 domains, set as this to 30000.

# Apply this to all mailbox servers!
zmlocalconfig -e ldap_cache_domain_maxsize=30000