[OpenLayers-Dev] Some of the WMS tiles not getting refreshed

[louvy.joseph at gmail.com]

Thanks Crhis, Andrea & Cameron. I still have the problem. Couple of notes.

1) Yes, I was already using the random number with mergeNewParams().
    wmsLayer.mergeNewParams({'foo': Math.random()});

And I do see that there is FOO value getting embedded in my WMS url.

2) Funny thing is that when I look at the tile in firebug by clicking 
Net->Images->wms->Response,  I see my new tile with proper image but the 
browser itself seem to display old tile. Why? Most of the tiles are okay 
except for one tile or rarely two tiles.

3) The response headers from firebug are:
 
Response Headers
Server 	Apache-Coyote/1.1
Content-Type 	image/png
Transfer-Encoding 	chunked
Date 	Wed, 05 Sep 2007 00:23:53 GMT
Request Headers
Host 	wms1.localhost:8080
User-Agent 	Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.6) 
Gecko/20070725 Firefox/2.0.0.6
Accept 	image/png,*/*;q=0.5
Accept-Language 	en-us,en;q=0.5
Accept-Encoding 	gzip,deflate
Accept-Charset 	ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive 	300
Connection 	keep-alive
Referer 	http://localhost:8080/polaris-web/edit



Do you see anything wrong in the header? I don't see "Pragma: No-Cache" 
in the header. Is that something to be worried about?


4) Andrea, are you referring to "Cache Enabled" & "Cache Time" field in 
geoserver console's under WFS feature edit screen? The "Cache Enabled" 
check box is not enabled and the "Cache Time" text field is empty.

5) The problem happens in both IE & Firefox.

6) Chris, is there anything I can debug around using the checkImagURL() 
event handler?

Thanks again
Louvy



Christopher Schmidt wrote:
> On Mon, Sep 03, 2007 at 09:24:25PM +0530, louvy.joseph at gmail.com wrote:
>   
>> Has anybody seen this behavior? I have lot of dynamic content on the 
>> server (i.e. geoserver); hence the WMS content is supposed to change all 
>> the time. When I refresh my WMS layer, 5% of the time, some of the tiles 
>> don't get refreshed. And these tiles are random. Rest of the tiles get 
>> refreshed fine.
>>
>> Has anybody seen this behavior? What could be happening? When I look at 
>> the WMS requests in my firebug, browser doesn't seem to generate the WMS 
>> tile requests in the first place (but I could be wrong on this fact).
>>
>> Any tips appreciated on how to debug? (I don't have any tilecache 
>> configured. It is plain geoserver to openlayers configuration. BTW, I 
>> don't have a public facing example to publish to the mailing list)
>>     
>
> Browsers tend to assume that the content in a given URL hasn't changed
> for longer than they should. Override your getURL function and make it
> append a random=Math.random():
> http://openlayers.org/pipermail/users/2007-January/000615.html is close,
> but if you wnat 'constant' refresh, you'll have to do a bit more
> legwork.
>
> Regards,
>