[Geoserver-users] Enabling no-cache headers for Geoserver tiles

GeoServer GeoServer User
1

Hey, folks:

I am using Geoserver 1.6.5 + Tomcat 4 to generate map tiles for a Google
mashup. I need to _enable_ no-cache headers for the tiles being sent by
Geoserver. We are currently doing this on the browser side (adding a random
number to the tile requests), and this seems to have resulted in a pretty
bad memory leak in IE. We need to test and see if IE's behavior is better
when the server is instructing it not to cache.

I've been searching, and everything I find talks only about disabling
no-cache or enabling various types of caching, and doesn't seem applicable
to a situation where the problem is that these headers aren't being sent.
(Or, to Tomcat 4.) If someone could tell me how to do this, or point me
toward the proper documentation, I'd be grateful.

Thanks,
Dhall
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2

Hi,

I assume you've tried setting it to Cache and then time to 0 ?

If that doesn't help, it's just a cheap shot, you can proxy through Apache. If you have mod_expire installed and set the default to be no-cache then that will apply even to proxied responses.

http://geoserver.org/display/GEOSDOC/How+to+proxy+Jetty+through+Apache+on+port+80

-Arne

DHall wrote:

Hey, folks:

I am using Geoserver 1.6.5 + Tomcat 4 to generate map tiles for a Google
mashup. I need to _enable_ no-cache headers for the tiles being sent by
Geoserver. We are currently doing this on the browser side (adding a random
number to the tile requests), and this seems to have resulted in a pretty
bad memory leak in IE. We need to test and see if IE's behavior is better
when the server is instructing it not to cache.

I've been searching, and everything I find talks only about disabling
no-cache or enabling various types of caching, and doesn't seem applicable
to a situation where the problem is that these headers aren't being sent.
(Or, to Tomcat 4.) If someone could tell me how to do this, or point me
toward the proper documentation, I'd be grateful.

Thanks,
Dhall
  
--
Arne Kepp
OpenGeo - http://opengeo.org
Expert service straight from the developers

3

Unfortunately, my packet sniffing reveals that this doesn't seem to result
in the behavior I want for either IE7 or FF2. :frowning: I see the cache-control
headers on the tile response, but the tiles aren't actually being reloaded
from the WMS by either browser when the overlay.refresh() function
provided by the Google API is called.

Proxying through Apache may not be an option, either. We're pretty much
stuck with what's currently installed, and that does not include Apache.
We've been lucky in that despite being stuck using jdk1.4 and tomcat 4
here, we're seeing excellent behavior from geoserver.

Thanks,
Deirdre

-----Original Message-----
From: Arne Kepp [mailto:ak@anonymised.com]
Sent: Wednesday, December 10, 2008 4:34 PM
To: DHall
Cc: geoserver-users@lists.sourceforge.net
Subject: Re: [Geoserver-users] Enabling no-cache headers for Geoserver
tiles

Hi,

I assume you've tried setting it to Cache and then time to 0 ?

If that doesn't help, it's just a cheap shot, you can proxy through
Apache. If you have mod_expire installed and set the default to be
no-cache then that will apply even to proxied responses.

http://geoserver.org/display/GEOSDOC/How+to+proxy+Jetty+through+Apache+on+
port+80

-Arne

DHall wrote:

Hey, folks:

I am using Geoserver 1.6.5 + Tomcat 4 to generate map tiles for a Google
mashup. I need to _enable_ no-cache headers for the tiles being sent by
Geoserver. We are currently doing this on the browser side (adding a

random

number to the tile requests), and this seems to have resulted in a

pretty

bad memory leak in IE. We need to test and see if IE's behavior is

better

when the server is instructing it not to cache.

I've been searching, and everything I find talks only about disabling
no-cache or enabling various types of caching, and doesn't seem

applicable

to a situation where the problem is that these headers aren't being

sent.

(Or, to Tomcat 4.) If someone could tell me how to do this, or point me
toward the proper documentation, I'd be grateful.

Thanks,
Dhall
  
--
Arne Kepp
OpenGeo - http://opengeo.org
Expert service straight from the developers

4

Deirdre Hall ha scritto:

Unfortunately, my packet sniffing reveals that this doesn't seem to result
in the behavior I want for either IE7 or FF2. :frowning: I see the cache-control
headers on the tile response, but the tiles aren't actually being reloaded
from the WMS by either browser when the overlay.refresh() function
provided by the Google API is called.

Proxying through Apache may not be an option, either. We're pretty much
stuck with what's currently installed, and that does not include Apache.
We've been lucky in that despite being stuck using jdk1.4 and tomcat 4
here, we're seeing excellent behavior from geoserver.

Please open an improvement request in jira.codehaus.org.
We'll process it as time permits, if you want a quick solution
you'll either have to change the code yourself or look
for a commercial support provider to code it up for you
(pointers here: http://geoserver.org/display/GEOS/Commercial+Support)

Cheers
Andrea

--
Andrea Aime
OpenGeo - http://opengeo.org
Expert service straight from the developers.