Forum OpenACS Development: Re: Re: Re: Re: Deadlock / ShareLock fix!

content_item__new is sufficient in our cases as well, did you add in specific place?
We plan to provide a patch for HEAD (deadlocks).
Will be good if other OCT members comment on what we have discussed, then we can apply the patch to HEAD.
Also, we need a patch for dropping the use of cr_dummy in favor of the function call.
Collapse
Posted by Gustaf Neumann on
today is familiy day. this evening i'll provide a patch/update.
Collapse
Posted by Gustaf Neumann on
Here is a patch + upgrade script.

The approach with the BEGIN .. END in dml statements (mentioned earlier) lead to other problems, so i changed for the time being the few instances, where sql statements inserts directly into the TABLENAMEi view, the command from db_dml to db_0or1row. This is necessary, since the rule processor of postgres rewrites now the insert rule into a select query calling the stored procedure. This happens only in three cases (acs-content-repository, dynamic-types, xowiki). There is as well an update to the TABLENAMEi view in form-procs of dynamic types, it might be necessary to check if this is ok.

The upgrade script contains the altered rule generator which generates now a rule + a stored procedure, which uses a variable to hold the temporary result. This should be faster than the old version based on cr_dummy, which essentially allows only one insert at a time.

The code was only tested with postgresql 8.0.

This patch is not intended for the general public,
but for developers for testing purposes. so, the
patch is against CVS head.

How to use this:
- make a dump of your database
- run the .sql file with
psql -U ... < cr-deadlock-duplicate-upgrade.sql
- cd packages; patch -p0 < cr-deadlock-duplicate.patch-HEAD

http://media.wu-wien.ac.at/download/cr-deadlock-duplicate-upgrade.sql
http://media.wu-wien.ac.at/download/cr-deadlock-duplicate.patch-HEAD

If we want to proceed with the patch, it will be necessary to provide a patch for content-types.sql as well.

enjoy.

Collapse
Posted by Derick Leony on
The patch worked great for one of our development instances with PG8.0.

I tried to modify the SQL script in order to apply the patch on PG 7.4.7 but since the "new" object of the rule can't be sent as a parameter the functions have to be generated with a parameter per column. This led to another problem because there are some revision views (e.g. as_sessionsi) with more than 32 attributes and 32 is the parameter limit for PG functions.

So, the chosen approach was to apply this change to every view with 32 or less attributes. Any advice will be really appreciated, though I think upgrading to PG8.1 would be the best to do :)