How to modify ldap.conf to switch to the secondary ldap server more quickly.

Solution Verified - Updated -


  • Red Hat Enterprise Linux 4
  • Red Hat Enterprise Linux 5

  • nssldap


  • It takes long time to switch from primay LDAP server to the secondary LDAP server when the primary ldap server has trouble.
  • Are there some tunings to improve it?


  • Normally "getent passwd" can reproduce this issue. "strace getent passwd" can help to troubleshoot the cause of the delay.
  • Values are in seconds so adjust this to the needs of the environment.  In this example we use 20 seconds.
  • If the delay is caused by doing search. specify a timeout value for search by editing the file /etc/ldap.conf
    timelimit 20

  • If the delay is caused by binding from client to LDAP server, for example, 1, if the primary server is unreachable, 2, if the LDAP daemon hangs, then "bind_timelimit" can be set to control the seconds of timeout by doing setup "bind_policy soft" and "bind_timelimit" in /etc/ldap.conf
    bind_policy soft
    bind_timelimit 20

Please see the man page (man nss_ldap) for details.

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