Administrators can use various means to monitor the servers through SNMP, the Administrative Console, JConsole, LDAP command-line tools, and the Stats Logger. The Monitor Backend contains an entry per component or activity being monitored. The list of all monitor entries can be seen using the ldapsearch command as follows:
$ bin/ldapsearch --hostname server1.example.com \
  --port 1389 \
  --bindDN "uid=admin,dc=example,dc=com" \
  --bindPassword secret \
  --baseDN "cn=monitor" "(objectclass=*)" cn

Monitoring Components

The following table lists a subset of monitor entries.

Component Description

Active operations

number of active persistent searches.

Backends

Provides general information about the state of a server backend, including the entry count. If the backend is a local database, there is a corresponding database environment monitor entry with information on cache usage and on-disk size.

Client connections

Provides information about all client connections to the server including a name followed by an equal sign and a quoted value, such as connID="15", connectTime="20100308223038Z".

Connection handlers

Provides information about the available connection handlers on the server including the LDAP and LDIF connection handlers.

Disk space usage

Provides information about the disk space available to various components of the server.

General

Provides general information about the state of the server, including product name, vendor name, and server version.

Index

Provides information on each index including the number of preloaded keys and counters for read, write, remove, open-cursor, and read-for-search actions. These counters provide insight into how useful an index is for a given workload.

HTTP/HTTPS Connection Handler Statistics

Provides statistics about the interaction that the associated HTTP connection handler has had with its clients, including the number of connections accepted, average requests per connection, average connection duration, total bytes returned, and average processing time by status code.

JVM stack trace

Provides a stack trace of all threads processing within the JVM.

LDAP Connection Handler Statistics

Provides statistics about the interaction that the associated LDAP connection handler has had with its clients, including the number of connections established and closed, bytes read and written, LDAP messages read and written, and operations initiated, completed, and abandoned.

Processing time histogram

Categorizes operation processing times into a number of user-defined buckets of information, including the total number of operations processed, overall average response time (ms), and number of processing times between 0ms and 1ms.

System information

Provides general information about the system and the JVM on which the server is running, including system host name, operation system, JVM architecture, Java home, and Java version.

Version

Provides information about the server version, including build ID, and revision number.

Work queue

Provides information about the state of the server work queue, which holds requests until they can be processed by a worker thread, including the requests rejected, current work queue size, number of worker threads, and number of busy worker threads.

The work queue configuration has a monitor-queue-time property set to true by default. This logs messages for new operations with a qtime attribute included in the log messages. Its value is expressed in milliseconds and represents the length of time that operations are held in the work queue.