Red Hat SummitChapter 4. Server monitoring information in cn=monitor
Review global read-only monitoring attributes under cn=monitor to monitor server activity and counters.
The cn=monitor entry and its children are read-only, clients cannot directly modify them. The server updates this information automatically. The only attribute that you can change is the aci attribute.
If the nsslapd-counters attribute in cn=config is set to on (the default setting), then all of the counters kept by Red Hat Directory Server instance increment using 64-bit integers, even on 32-bit machines or with a 32-bit version of Directory Server. For the cn=monitor entry, the 64-bit integers are used with the opsinitiated, opscompleted, entriessent, and bytessent counters.
The nsslapd-counters attribute enables 64-bit support for these specific database and server counters. The counters which use 64-bit integers are not configurable; the 64-bit integers are either enabled for all the allowed counters or disabled for all allowed counters.
4.1. backendMonitorDN
The backendMonitorDN attribute displays the DN for each Red Hat Directory Server database backend.
For further information on monitoring the database, see the following sections:
- Section 6.4.11, “Database attributes under cn=<attribute_name>,cn=encrypted attributes,cn=<database_name>,cn=ldbm database,cn=plugins,cn=config”
- Section 6.4.6, “Database attributes under cn=database,cn=monitor,cn=ldbm database,cn=plugins,cn=config”
- Section 6.5.4, “Database link attributes under cn=monitoring,cn=<database_link_name>,cn=chaining database,cn=plugins,cn=config”
4.2. bytesSent
The bytesSent attribute displays the number of bytes sent by Red Hat Directory Server.
4.3. connection
The connection attribute lists open connections and associated status and performance related information and values.
An open connection is displayed in the following format:
connection: A:YYYYMMDDhhmmssZ:B:C:D:E:F:G:H:I:IP_addressFor example:
connection: 69:20200604081953Z:6086:6086:-:cn=proxy,ou=special_users,dc=example,dc=test:0:11:27:7448846:ip=192.0.2.1-
A is the connection number, which is the number of the slot in the connection table associated with this connection. This is the number logged as
slot=Ain the access log message when this connection was opened, and usually corresponds to the file descriptor associated with the connection. The attributedTableSizeshows the total size of the connection table. - YYYYMMDDhhmmssZ is the date and time, in GeneralizedTime form, at which the connection was opened. This value gives the time in relation to Greenwich Mean Time.
- B is the number of operations received on this connection.
- C is the number of completed operations.
-
D is
rif the server is in the process of reading BER from the network, empty otherwise. This value is usually empty (as in the example). -
E this is the bind DN. This may be empty or have value of
NULLDNfor anonymous connections. -
F is the connection maximum threads state:
1is in max threads,0is not. - G is the number of times this thread has hit the maximum threads value.
- H is the number of operations attempted that were blocked by the maximum number of threads.
-
I is the connection ID as reported in the logs as
conn=connection_ID. - IP_address is the IP address of the LDAP client.
B and C for the initiated and completed operations should ideally be equal.
4.4. currentConnections
The currentConnections attribute displays the number of currently open and active Red Hat Directory Server connections.
4.5. currentTime
The currentTime attribute displays the current time in Greenwich Mean Time indicated by generalizedTime syntax Z notation. For example, 20220202131102Z.
4.6. dTableSize
The dTableSize attribute displays the size of the Red Hat Directory Server connection table.
Each connection is associated with a slot in this table and usually corresponds to the file descriptor used by this connection. For more information, see nsslapd-maxdescriptors and nsslapd-reservedescriptors.
4.7. entriesSent
The entriesSent attribute displays the number of entries sent by Red Hat Directory Server.
4.8. nbackEnds
The nbackEnds attribute displays the number of Red Hat Directory Server database backends.
4.9. opsInitiated
The opsInitiated attribute displays the number of Red Hat Directory Server completed operations.
4.10. readWaiters
The readWaiters attribute displays the number of connections with pending requests that are not currently serviced by a thread in Red Hat Directory Server.
4.11. startTime
The startTime attribute displays Red Hat Directory Server start time in Greenwich Mean Time, indicated by generalizedTime syntax Z notation. For example, 20220202131102Z.
4.12. threads
The threads attribute displays the number of threads Red Hat Directory Server used. The value must correspond to nsslapd-threadnumber in cn=config.
4.13. totalConnections
The totalConnections attribute displays the total number of Red Hat Directory Server connections. This number includes connections that were opened and closed since the server was last started in addition to the currentConnections.
4.14. version
The version attribute displays the Red Hat Directory Server vendor, version, and build number. For example, 389-Directory/2.0.14 B2022.082.0000.
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