[Zope-dev] Making a ZSQL.DA fully multi-threaded?

sathya zope2 at zeomega.com
Fri Jul 16 14:09:45 EDT 2004


sqlrelay seems to hold some promise for connection pooling although I am
not sure if theres support for sapdb
Brad Clements wrote:

>On 16 Jul 2004 at 8:57, Chris Withers wrote:
>
>  
>
>>This often means that many more database connections are opened than are
>>actually necessary. And if you start timing out inactive database
>>connectiosn on the database side, you're in for a world of pain and
>>suffering.
>>
>>I branched ZOracleDA some time ago to move away from this model for that
>>very reason...
>>
>>What's the actual problem you're experiencing?
>>    
>>
>
>I have set the SAPDB timeout to 32400 seconds. However when running with more than 1 
>thread I still get "mysterious segfaults" in the sapdbapi component.
>
>The SAP  folks say their adapter is "multi-thread capable", but I've come to believe that only 
>means that it's ok to open a connection in one thread and use it in another, but NOT to have 
>2 threads make requests on the same connection at the same time.
>
>Also, two threads can' t open a connection "at the same time" because their connection table 
>management isn't "thread safe".
>
>What I need, I suppose, is a DB connection pool mechanism of some kind. I also have 
>Python extensions that need a connection as well. Getting the actual database connection 
>from a DA stinks (ie, it's not really possible). I'd like to see an API extension to ZopeDA's to 
>allow Pythonscripts, Products and external methods get an actual db connection. But that I 
>suppose is a problem to solve later.
>
>I think I will take a look at ZOracleDA to see what you did. 
>
>
>  
>






More information about the Zope-Dev mailing list