Re: [basedb-devel] intermittent hibernate errors when using BASE API

[Nicklas N. <ni...@th...>]

Bob MacCallum wrote:
> Hi Nicklas,
> 
> I'll double check but I think we're sharing one DbControl across the whole
> webapp, so that will be the first place to look.

This will definitely give you a lot of problems since a DbControl is not 
thread-safe. You may also run into memory problems since every item that 
  has been loaded from the database will be stored in a cache. If you 
use one DbControl for everything you will end up with the entire 
database as  Java objects in memory.

In other words, every request to the web application needs it's own 
DbControl.

/Nicklas


> 
> Thanks for the hint.  Will post back when I have a solution.
> 
> cheers,
> Bob.
> 
> 
> Nicklas Nordborg writes:
>  > Bob MacCallum wrote:
>  > > Quick follow up to:
>  > > http://www.mail-archive.com/bas...@li.../msg00316.html
>  > > 
>  > > The problem seems to be triggered by concurrent access to our BASE-based web
>  > > application (for example, me and googlebot).
>  > > 
>  > > That doesn't bring me any closer to understanding what exactly is going on,
>  > > but I thought I would share.
>  > > 
>  > > I wonder if similar stacktraces occur on a busy multi-user BASE server?
>  > > 
>  > 
>  > Are you sharing objects (eg. an ItemQuery, DbControl, etc.) between 
>  > different threads? I think the problem can be caused by multiple threads 
>  > that are accessing the same non-threadsafe object at the same time.
>  > 
>  > /Nicklas
>  > 
>  > 
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