18. Monitoring
slapd(8) supports an optional LDAP monitoring interface you can use to obtain information regarding the current state of your slapd instance. For instance, the interface allows you to determine how many clients are connected to the server currently. The monitoring information is provided by a specialized backend, the monitor backend. A manual page, slapd-monitor(5) is available.
When the monitoring interface is enabled, LDAP clients may be used to access information provided by the monitor backend, subject to access and other controls.
When enabled, the monitor backend dynamically generates and returns objects in response to search requests in the cn=Monitor subtree. Each object contains information about a particular aspect of the server. The information is held in a combination of user applications and operational attributes. This information can be access with ldapsearch(1), with any general-purpose LDAP browser, or with specialized monitoring tools. The Accessing Monitoring Information section provides a brief tutorial on how to use ldapsearch(1) to access monitoring information, while the Monitor information section details monitoring information base and its organization.
While support for the monitor backend is included in default builds of slapd(8), this support requires some configuration to become active. This may be done using either cn=config or slapd.conf(5). The former is discussed in the Monitor configuration via cn=config section of this of this chapter. The latter is discussed in the Monitor configuration via slapd.conf(5) section of this chapter. These sections assume monitor backend is built into slapd (e.g., --enable-monitor=yes, the default). If the monitor backend was built as a module (e.g., --enable-monitor=mod, this module must loaded. Loading of modules is discussed in the Configuring slapd and The slapd Configuration File chapters.