postgis cyclic performance hit

[Romolo Manfredini]

The informations are very few, but such a behaviour may depends on several
factors like:
Few postgres connections
then  if you are using apache
bad configuration of apache (few childs)
fast recycling of  servers (respaning child too often)
are you using the cgi directly or some interface ?
on my developer machine using winxp / apache / php / postgres / postgis /
phpmapscript and persistent connections never had cyclic performance hits
and response times are rather good with very large layers.
BTW I had to patch tcpip.sys for half-open connection issues (1000
connections allowed) as I had issues while testing with firefox configured
for maximum performances.

----- Original Message ----- 
From: "Richard Duivenvoorde" <rdmailings at DUIF.NET>
To: <MAPSERVER-USERS at LISTS.UMN.EDU>
Sent: Thursday, April 19, 2007 5:00 PM
Subject: [UMN_MAPSERVER-USERS] postgis cyclic performance hit


> Hi List,
> I'm running a developer machine windows, postgis/mapserver.
>
> It contains one small layer (50 points).
>
> If I run a ogc-mapserver request (in a browser) for an image of those
> points, the performance behaves strange:
> - about 10 responses ok: about a few hundred milliseconds
> - then one VERY slow one: about 4 seconds
> repeating that every 9-14 requests
>
> created gist index on geometry layer
> created btree index on id column
> gave postgresql some more memory
>
> still the same result.
>
> QUESTION:
> - any people running mapserver/postgis on a windows machine and having
> good response times
> - somebody a clue to this cyclic 'bad response time' behaviour?
>
> Thanks
>
> Richard Duivenvoorde
>