[Qgis-developer] MTR and Postgis - lots of crashes

[Denis Rouzaud]

QGIS allows 5 max I think
So whenever QGIs reaches the max number of connections, it can't fetch 
the requested layer but still waits for it...

On 06.11.2014 11:01, Andreas Neumann wrote:
> Hi Denis,
>
> Thanks for the hint.
>
> I had a check on the nr of open connections on our PostgreSQL server.
>
> The results of
>
> SELECT sum(numbackends) FROM pg_stat_database;
>
> are always in the 20ies.
>
> I allow 100 connections on the PostgreSQL server. So this does not 
> explain the problems.
>
> The crashes always happen directly after project load. Once its loaded 
> without a crash I never have subsequent crashes.
>
> So something critical seems to happen on project load.
>
> Andreas
>
>
> On 06.11.2014 10:48, Denis Rouzaud wrote:
>>
>> On 06.11.2014 10:43, Andreas Neumann wrote:
>>> Hi,
>>>
>>> Am I the only one that still gets a lot of crashes with complex 
>>> projects when the data sources are on Postgis and MTR (parallel 
>>> rendering in multiple cores) is turned on? I get most crashes on 
>>> Windows, hardly any on Linux, but this may be due to the fact that 
>>> Linux accesses Postgis locally, whereas the Win QGIS clients access 
>>> Postgis remotely. Turning off MTR --> no more crashes.
>>>
>>> Is MTR and Postgis working flawlessly for everyone?
>>>
>>> These crashes really annoy me and I have to turn off MTR until these 
>>> problems are fixed.
>>>
>>> Thank you for any hints / sharing your experiences with Postgis and 
>>> MTR.
>> I experienced freezes with MTR when I used joined attributes for 
>> symbology/labelling. The joins being not cached.
>> My interpretation was that the number of allowed connections to 
>> postgres reached its maximum, and hence no connection is available to 
>> fetch the layers used for labeling/symbology.
>>
>> Caching all my joins saved the problem on my side.
>>
>>
>> I don't experience any trouble either on win or linux, and I suppose 
>> I can say I have complex projects ;)
>>
>> Denis
>>
>>
>