TYPO3 Core

http://lists.netfielders.de/pipermail/typo3-german/2009-January/054840.html
http://lists.netfielders.de/pipermail/typo3-german/2009-January/054828.html

Seems to be urgent due to many persons having unexpected breakedowns.

The main problem is that the Locking Mechanism doesn't work!

The settings in the localconf or in the class-file aren't relevant when that fault is fixed.

Disabling the locking at all isn't a good ideas since it may lead to other conflicts on concurrent requests in the frontend - e.g. in template parsing, old "page is being generated" message and duplicates on writing cached data.

Did you use other settings than "simple"? E.g. the semaphore locking works quite good on my site. However, it's true, that the locking has to be optimized in case an extension breaks and prevents the locking mechanism from releasing the lock again.

Hm... an "enhancement" of the simple lock could be to define the lock-timeout (maximum time to wait a lock gets released by another process) different...
Lock-timeout should be max. 90% of the PHP max-execution time! I guess that this is the reason of the mentioned crashes and misbehaviours on that...

The MySQL function GET_LOCK() provides very sophisticated locking (compared to the "simple" mode) and should be available to every Typo3 installation with MySQL backend. Probably this method can be used as default if a MySQL DB is used.
See: http://dev.mysql.com/doc/refman/4.1/en/miscellaneous-functions.html#function_get-lock

IMHO the "simple" function is much too .... simple. It should be substituted by "semaphore" or the MySQL GET_LOCK() function if available.

I would be happy to provide a patch adding the MySQL locking if you want.

Sorry for delay, forgot to monitor the issue.

Oliver,

No I didn't try another mode than "simple".
I deactivated it only after having problems over 1-2 month.

In the Mailingist problems have to do with it often, here is a newer one from someone who verified a bit more than me:

http://lists.netfielders.de/pipermail/typo3-german/2009-February/055600.html

Leonhard,

I would be happy to provide a patch adding the MySQL locking if you want.

I don't know really much about locking, so I prefer letting other persons solve the problem. But if you're able to create a better solution, i'd be interested in it.

TYPO3 4.2.8:
The description of [SYS][lockingMode] should be updated. The last sentence says: "Default is disable".

But the current default setting is "simple".

The settings in the install-tool still are

'lockingMode' => 'simple'

Furthermore I don't know if or what has changed under the hood concerning the locking-mechanism. So even the default setting is 'simple' as default-mode the function itself maybe different.

The most confusing was that documentation and description in install-tool about the default-mode have been / are? different than reality, but sure it would be nice having a working default setting too - just improvable by admins who know what it is about.

The documentation in install tool still says "Default is 'disable'".