Re: 389 LDAP Multi-threading question

Rich Megginson <rmeggins@xxxxxxxxxx> · Tue, 27 Mar 2012 15:52:42 -0600



    On 03/27/2012 03:42 PM, Justin Piszcz wrote:
    
      
        Hello,
         
        Had an inquiry regarding ns-slapd, was
          multi-threading always supported from the first public
          release?
      
    
    Yes.

    
        I’ve seen ns-slapd (an older version) sit
          pegged at or near 100% CPU utilization on a multi-core Xeon
          system.
      
    
    Would like to know if you can repeat that with 1.2.10.4.  If so,
    please provide platform and details, and a reproducer if possible.

    
        I’ve read elsewhere that someone has seen
          it hit 200% on a 2 way Xeon system (from 2007)
        http://www.mail-archive.com/fedora-directory-users@xxxxxxxxxx/msg06164.html
      
    
    Sure.  Enabling a very verbose log level will cripple the server
    performance.

    
        There are obviously other factors in terms
          of the DB, what you are doing, in terms of add or add+delete;
          however was curious if there was an a parameter or a compile
          time setting that enables/disables threads, if the default was
          always to use multiple threads(?) or is it the case that there
          are other non-optimized parameters being used that would not
          allow ns-slapd to utilize the other N number of cores?
      
    
    The directory server does not know or care about how many cpus/cores
    are in the machine.  It relies on the native threading library and
    the kernel thread schedule to allocate threads among the cpus/cores.

    
    See

http://docs.redhat.com/docs/en-US/Red_Hat_Directory_Server/9.0/html/Configuration_Command_and_File_Reference/Core_Server_Configuration_Reference.html#cnconfig-nsslapd_maxthreadsperconn_Maximum_Threads_per_Connection

    
    There is also a "hidden" attribute nsslapd-threadnumber.  By default
    this value is 30.  You might be able to achieve better throughput
    for your use case by setting this to 2*number of cores on your
    machine.  We would be interested in hearing your results if you try
    this out.

    
        Justin.
      
      
      --
389 users mailing list
389-users@xxxxxxxxxxxxxxxxxxxxxxx
https://admin.fedoraproject.org/mailman/listinfo/389-users
    
    
--
389 users mailing list
389-users@xxxxxxxxxxxxxxxxxxxxxxx
https://admin.fedoraproject.org/mailman/listinfo/389-users