Tickets :: [#2913] memcached session locking

6.0.0-beta1

7/15/25

Summary	memcached session locking
Queue	Horde Framework Packages
Queue Version	HEAD
Type	Enhancement
State	Resolved
Priority	1. Low
Owners	Horde Developers (at)
Requester	adrieder (at) sbox (dot) tugraz (dot) at
Created	11/03/2005 (7194 days ago)
Due
Updated	02/22/2007 (6718 days ago)
Assigned	11/03/2005 (7194 days ago)
Resolved	12/02/2005 (7165 days ago)
Milestone
Patch	No

02/22/2007 04:35:22 PM	Jan Schneider	Comment #10	Reply to this comment
Wouldn't it make more sense to store a lock key in the memcache server instead of relying on a shared file system for locking?

12/06/2005 04:25:12 PM	adrieder (at) sbox (dot) tugraz (dot) at	Comment #9	Reply to this comment
There is still a bug in the driver: the function _unlockSession() should not take a parameter at line 233

12/05/2005 07:58:33 PM	Chuck Hagenbuch	Deleted Original Message

12/05/2005 04:09:18 PM	kevin_myer (at) iu13 (dot) org	Comment #8	Reply to this comment
I'd propose a slightly different fix - if you call _unlockSession without an $id, it's doing nothing. I think this patch would be desired behaviour - remove the flock, then remove the file itself. Argh, except, close() isn't setup to take $id as an argument, so that call to _unlockSession fails.. I missed the introduction of the $_fp resource. In which case, the original patch is more or less correct.

12/05/2005 03:56:47 PM	kevin_myer (at) iu13 (dot) org	Comment #7 New Attachment: memcached.php[2].patch	Reply to this comment
Cool. I've cleaned it up and committed it to HEAD and FRAMEWORK_3. Thanks! I noticed that you cleanups introduced a small bug. The close() function doesn't have an argument. I attached a patch which should deal with this problem, I'd propose a slightly different fix - if you call _unlockSession without an $id, it's doing nothing. I think this patch would be desired behaviour - remove the flock, then remove the file itself.

12/02/2005 08:57:10 PM	adrieder (at) sbox (dot) tugraz (dot) at	Comment #6 New Attachment: memcached.php[1].patch	Reply to this comment
Cool. I've cleaned it up and committed it to HEAD and FRAMEWORK_3. Thanks! I noticed that you cleanups introduced a small bug. The close() function doesn't have an argument. I attached a patch which should deal with this problem,

12/02/2005 06:03:38 PM	Chuck Hagenbuch	Comment #5 State ⇒ Resolved	Reply to this comment
Cool. I've cleaned it up and committed it to HEAD and FRAMEWORK_3. Thanks!

12/02/2005 03:26:14 PM	adrieder (at) sbox (dot) tugraz (dot) at	Comment #4	Reply to this comment
Is this patch stable/in use? I'm not clear exactly which versions the people having trouble with memcached are using. We use it since I posted it. 4 servers 10000 users. It works, which means we do not see the "message not found" problem anymore. One thing is which I had do do additionally: Clean the tmp dir from stale session locks from time to time. Cronjob: find /tmp/lock_* \( -type f -amin +120 \) -exec rm -f {} \;

12/02/2005 05:09:10 AM	Chuck Hagenbuch	Comment #3 State ⇒ Feedback	Reply to this comment
Is this patch stable/in use? I'm not clear exactly which versions the people having trouble with memcached are using.

11/03/2005 08:15:56 PM	Jan Schneider	Assigned to Horde Developers State ⇒ Assigned

11/03/2005 08:01:19 PM	adrieder (at) sbox (dot) tugraz (dot) at	Comment #2	Reply to this comment
Forgot to mention: The idea and solution is based on Gary Windham's <windhamg@email.arizona.edu> memcached_flock driver. He kindly provided the code.

11/03/2005 07:04:22 PM	adrieder (at) sbox (dot) tugraz (dot) at	Comment #1 Priority ⇒ 1. Low Type ⇒ Enhancement Summary ⇒ memcached session locking Queue ⇒ Horde Framework Packages New Attachment: memcached.php.patch State ⇒ New	Reply to this comment
The attached patch helps to get around the "requested message not found" issue, which is due to no serialization of concurrent session access.