Red Hat Summit7.7. 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
'%20d='M201.5%20305.5c-13.8%200-24.9-11.1-24.9-24.6%200-13.8%2011.1-24.9%2024.9-24.9%2013.6%200%2024.6%2011.1%2024.6%2024.9%200%2013.6-11.1%2024.6-24.6%2024.6zM504%20256c0%20137-111%20248-248%20248S8%20393%208%20256%20119%208%20256%208s248%20111%20248%20248zm-132.3-41.2c-9.4%200-17.7%203.9-23.8%2010-22.4-15.5-52.6-25.5-86.1-26.6l17.4-78.3%2055.4%2012.5c0%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.3%2024.9-24.9s-11.1-24.9-24.9-24.9c-9.7%200-18%205.8-22.1%2013.8l-61.2-13.6c-3-.8-6.1%201.4-6.9%204.4l-19.1%2086.4c-33.2%201.4-63.1%2011.3-85.5%2026.8-6.1-6.4-14.7-10.2-24.1-10.2-34.9%200-46.3%2046.9-14.4%2062.8-1.1%205-1.7%2010.2-1.7%2015.5%200%2052.6%2059.2%2095.2%20132%2095.2%2073.1%200%20132.3-42.6%20132.3-95.2%200-5.3-.6-10.8-1.9-15.8%2031.3-16%2019.8-62.5-14.9-62.5zM302.8%20331c-18.2%2018.2-76.1%2017.9-93.6%200-2.2-2.2-6.1-2.2-8.3%200-2.5%202.5-2.5%206.4%200%208.6%2022.8%2022.8%2087.3%2022.8%20110.2%200%202.5-2.2%202.5-6.1%200-8.6-2.2-2.2-6.1-2.2-8.3%200zm7.7-75c-13.6%200-24.6%2011.1-24.6%2024.9%200%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.1%2024.9-24.6%200-13.8-11-24.9-24.9-24.9z'/%3e%3c/svg%3e){kind=small}