Forum LAMS for Tech-Heads - General Forum: Problem with administration


 
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1: Problem with administration
10/10/07 02:23 AM
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I have problem with administration and I don't get it.
Sometimes when I add new user to the group, I can't do that
and I see error report:

org.springframework.orm.hibernate3.HibernateSystemException: org.jboss.cache.lock.TimeoutException: read lock for /org/lamsfoundation/lams/usermanagement/UserOrganisation/org.lamsfoundation.lams.usermanagement.UserOrganisation#84 could not be acquired by Thread[http-0.0.0.0-8090-49,5,jboss] after 15000 ms. Locks: Read lock owners: [] Write lock owner: Thread[http-0.0.0.0-8090-30,5,jboss] , lock info: write owner=Thread[http-0.0.0.0-8090-30,5,jboss] (org.jboss.cache.lock.LockStrategyReadCommitted@e3e40a); nested exception is org.hibernate.cache.CacheException: org.jboss.cache.lock.TimeoutException: read lock for /org/lamsfoundation/lams/usermanagement/UserOrganisation/org.lamsfoundation.lams.usermanagement.UserOrganisation#84 could not be acquired by Thread[http-0.0.0.0-8090-49,5,jboss] after 15000 ms. Locks: Read lock owners: [] Write lock owner: Thread[http-0.0.0.0-8090-30,5,jboss] , lock info: write owner=Thread[http-0.0.0.0-8090-30,5,jboss] (org.jboss.cache.lock.LockStrategyReadCommitted@e3e40a)

Then when I try to add new lesson or to add/remove users from the group I can't do that and I see similar report...

Does Anybody know what is going on ??

Posted by Adam Stecyk

2: Re: Problem with administration
In response to 1 10/10/07 02:26 AM
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One more thing:
When I try to edit student account (Administration - Find user - edit) I still can't do anything and I see error report as above.

It seems that one operation (adding new user) made the whole group impossible to manage...

Posted by Adam Stecyk

3: Re: Re: Problem with administration
In response to 2 10/10/07 05:32 PM
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Adam,

I'm looking into this.

I'm not sure why you are getting the problem repeated when you do Administration - Find user - edit. You could try clearing the user cache - in SysAdmin go to "Cache Management" and click on the "Remove" link. This will attempt to clear any user details out of the cache.

If people are logged in, then their details will be recached again pretty quickly, but its worth a try.

Fiona

Posted by Fiona Malikoff

4: Re: Re: Re: Problem with administration
In response to 3 10/11/07 01:51 AM
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I can't reproduce the problem, but we have heard of other users having this problem. But because I can't reproduce it, we might just have to try a few things to see if we can track down the problem.

Could you check your transaction isolation setting for MySQL? Can you try to find your mysql.ini file (under Windows) or my.conf (on Unix/Linux/Mac).

The mysql.ini (Windows) is usually in either your MySQL Server directory (e.g. C:\Program Files\MySQL Server 5.0) or in your Windows directory (e.g. C:\Windows).

The my.cnf (*nix/Mac) is usually in \etc.

Find the entry "transaction-isolation". It should be set to READ-COMMITTED:

transaction-isolation=READ-COMMITTED

What is it set to?

We have the cache (which is what is throwing the exception) set to match READ-COMMITTED.

I'm also looking into whether we can use a newer version of the caching software, as that has some different options.

Fiona

Posted by Fiona Malikoff

5: Re: Re: Re: Re: Problem with administration
In response to 4 10/11/07 02:25 PM
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Adam,

Note that after changing the transaction-isolation in the mysql.ini, you will need to restart mysql to take effect. So first stop LAMS, then MySQL. Start MySQL and then LAMS again and that should do.


Ernie

Posted by Ernie Ghiglione

6: Re: Re: Re: Re: Re: Problem with administration
In response to 5 10/15/07 06:16 AM
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I have checked the MySQL configuration.
We have 5.0.38 version and there is no
transaction-isolation entry at all in my.conf file
do you suggest to add it ?

Posted by Adam Stecyk

7: Re: Re: Re: Re: Re: Re: Problem with administration
In response to 6 10/15/07 01:59 PM
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> do you suggest to add it ?

Yes.

Have a look at this page in the wiki regarding MySQL configuration for LAMS.

Thanks,

Ernie

Posted by Ernie Ghiglione

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