How to troubleshoot slow LDAP queries?

Issue

My Mirapoint Directory Server seems to be under heavy load or sluggish for a seemingly low rate of lookups from the LDAP clients, what is causing this and what should I do?

Solution

If your Mirapoint Directory Server appears to be under heavy load for a seemingly low rate of lookups from the LDAP clients, it is likely that some attributes that are used by LDAP clients in search criteria (query filter) are not indexed.

Using non-indexed attributes in search criteria (involving comparison), causes the Directory Server to search through the entire LDAP database for each and every query, which is highly inefficient and causes undue load on the Directory Server.

Some symptoms on the Directory Server that are indicative of this problem are:

• CPU pegged at or near 100% all the time, but the value of LOAD is low.
• The log watch output of DIR.* events may indicate search failures due to search times exceeding the limit.

By default, Mirapoint Directory Server indexes the following attributes:

However, if the LDAP queries on the client side (Mirapoint) are using a query filter that looks like the following:

(&(objectclass=inetOrgPerson)(|(mail=$(login))(miLoginID=$(login))(mailroutingAddress=$(login))))

Then the attributes miLoginID and mailroutingAddress must be indexed on the Mirapoint Directory Server.