红帽全球峰会7.7. Adjusting the maximum number of file descriptors in the IdM Directory Server
A value can be defined for the DefaultLimitNOFILE parameter in the /etc/systemd/system.conf file. An administrator with root privileges can set the DefaultLimitNOFILE parameter for the ns-slapd process to a lower value by using the setrlimit command. This value then takes precedence over what is in /etc/systemd/system.conf and is accepted by the Identity Management (IdM) Directory Server (DS) as the value for the nsslapd-maxdescriptors attribute.
The nsslapd-maxdescriptors attribute sets the maximum, platform-dependent number of file descriptors that the IdM LDAP uses. File descriptors are used for client connections, log files, sockets, and other resources.
If no value is defined in either /etc/systemd/system.conf or by setrlimit, then IdM DS sets the nsslapd-maxdescriptors attribute to 1048576.
If an IdM DS administrator later decides to set a new value for nsslapd-maxdescriptors manually, then IdM DS compares the new value with what is defined locally, by setrlimit or in /etc/systemd/system.conf, with the following result:
-
If the new value for
nsslapd-maxdescriptorsis higher than what is defined locally, then the server rejects the new value setting and continues to enforce the local limit value as the high watermark value. - If the new value is lower than what is defined locally, then the new value will be used.
This procedure describes how to set a new value for nsslapd-maxdescriptors.
Prerequisites
- The LDAP Directory Manager password
Procedure
Retrieve the current value of the
nsslapd-maxdescriptorsparameter and make a note of it before making any adjustments, in case it needs to be restored. Enter the Directory Manager password when prompted.[root@server ~]# dsconf -D "cn=Directory Manager" ldap://<server_fqdn> config get nsslapd-maxdescriptors Enter password for cn=Directory Manager on ldap://server.example.com: nsslapd-maxdescriptors: 4096Modify the value of the
nsslapd-maxdescriptorsattribute. This example increases the value to8192.[root@server ~]# dsconf -D "cn=Directory Manager" ldap://<server_fqdn> config replace nsslapd-maxdescriptors=8192Authenticate as the Directory Manager to make the configuration change.
Enter password for cn=Directory Manager on ldap://server.example.com: Successfully replaced "nsslapd-maxdescriptors"-
Monitor the IdM Directory Server’s performance. If it does not improve, repeat this procedure and adjust
nsslapd-maxdescriptorsto a different value, or back to the default of4096.
Verification
Display the value of the
nsslapd-maxdescriptorsattribute and verify it has been set to your desired value.[root@server ~]# dsconf -D "cn=Directory Manager" ldap://<server_fqdn> config get nsslapd-maxdescriptors Enter password for cn=Directory Manager on ldap://server.example.com: nsslapd-maxdescriptors: 8192
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