Mac OS X Server AFP high CPU load problem

This discussion thread over on Apple’s forums documents a large number of system administrators who have their AFP (Apple File Protocol) creating a high CPU load and thus making the server unusable for their users.

Suggested workarounds which have anecdotally provided varied success (including none 🙁 ) include:

  • Turning off Spotlight on client machines
  • Turning off Spotlight indexing on the shared volumes
  • Executing

    defaults write /Library/Preferences/ -dict-add afp_wan_threshold -int 1000
    defaults write /Library/Preferences/ -dict-add afp_wan_quantum -int 131702

    on all 10.5.x client Macs.

  • Installing Security Update 2009-001 which states

    Description: A race condition in AFP Server may lead to an infinite loop. Enumerating files on an AFP server may lead to a denial of service. This update addresses the issue through improved file enumeration logic. This issue only affects systems running Mac OS X v10.5.6.

The problem was originally posted with respect to Mac OS X 10.5.4 on 29th of August 2008, and still seems unresolved for many people. And people wonder why it’s hard to argue that Mac OS X Server belongs in the data centre.