[opencms-dev] Problem for (re)starting OpenCms

Niklas Eklund niklas at curalia.se
Mon Jul 14 13:47:02 CEST 2003


Brendon et al,

I've had the same, or similar maybe, problem (with Oracle 9) as well and 
traced it to some sort of deadlock in the java.sql.DriverManager. The 
system frooze with a couple of threads waiting in 
DriverManager.getConnection() and another in DriverManager.getDrivers(). 
The call to getDrivers() is done by the Oracle driver in it's connect() 
method()...
After searching (for "DriverManager") at Sun's Java bugparade it was 
clear that there is a problem with the DriverManager class and that Sun 
treats this as "Not a bug", and the only workaround seems to be to use 
the new DataSource paradigm instead.
Since the pool already seems to be thrown out in the development branch, 
this will be resolved in the future. I ended up replacing the calls (all 
239 of them ;) to DriverManager.getConnection() with another static 
method call that uses a DataSource type pool configured in tomcat. This 
seems to work for us, but haven't yet been thorougly tested...

Regards,

  Niklas

Brendon Price wrote:
> Hi all,
> 
> We had also encountered this problem previously and had spent several days
> trying to resolve the issue. In the end we added extensive debug code to the
> connection pool code of opencms. It appeared that the code hangs on the
> re-establishment of the connections in the connection pool. This is the
> point at which it times out the connections and re-estabilshes them. We
> could get the product to break every 2 minutes by reducing the timeout of
> connections down to 2 minutes.
> 
> In the end it was it appeared that the code fails within the JDBC connection
> creation. In the end we found an article that suggested we increase the
> number of file handles available to the Oracle 9i process (our DB). Once we
> did this our problem disappeared, however I think there is something else at
> work here that means we may have just hidden the symptoms of the real
> problem.
> 
> We made a changes to the
> /etc/sysctl.conf
> file and increased the number of file handles by adding the line
> 
> fs.file-max=32768
> 
> After a restart of the whole machine, the problem did not occur again, even
> with our previous test case (that failed every 2 minutes).
> 
> I hope this helps.
> 
> Regards
> Brendon
> 
> 
> -----Original Message-----
> From: Nicolas Delsaux
> To: opencms-dev at opencms.org
> Sent: 11/07/2003 9:40 p.m.
> Subject: Re: [opencms-dev] Problem for (re)starting OpenCms
> 
> On Fri, 11 Jul 2003 10:23:54 +0200 (CEST), Joachim Arrasz
> <info at arrasz.de> 
> wrote:
> 
> 
>>Hy Nicolas,
>>
>>what was your solution to this crazy thing?
>>How we can configurate Opencms to do that NOT?
> 
> 
> I've not yet found any kind of solution; In fact, the problem is
> currently 
> being corrected by a Tomcat restart each night.
> But, if anybody can have any idea on that problem, I'm willing to apply
> it 
> as soon as possible.
> 
>>thanx in advance
>>
>>Achim
> 
> 
> 





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