Up to version 6.12.0 we were not seeing any session being established
when static resources were being requested - which is desirable because
often search engines will hit thousands of times a day and most don't
use cookies or session rewriting so we end up creating a new session for
every static resource request that a search engine makes and that just
blows out the number of sessions.
We use:
// Use message digest over resource content for resource caching
// cache the version information for the lifetime of the application
IResourceVersion resourceVersion = new CachingResourceVersion(new
MessageDigestResourceVersion());
// cache resource with a version string in the filename
IResourceCachingStrategy cachingStrategy =
new
FilenameWithVersionResourceCachingStrategy("-ver-static-",
resourceVersion);
resourceSettings.setCachingStrategy(cachingStrategy);
and this worked fine up to version 6.12.0 where the code for
FilenameWithVersionResourceCachingStrategy.decorateReponse was:
/**
* set resource caching to maximum and set cache-visibility
to 'public'
*
* @param response
*/
@Override
public void
decorateResponse(AbstractResource.ResourceResponse response,
IStaticCacheableResource resource)
{
response.setCacheDurationToMaximum();
response.setCacheScope(WebResponse.CacheScope.PUBLIC);
}
Unfortunately in 6.13.0+ this code became:
/**
* set resource caching to maximum and set cache-visibility
to 'public'
*
* @param response
*/
@Override
public void
decorateResponse(AbstractResource.ResourceResponse response,
IStaticCacheableResource resource)
{
String requestedVersion =
RequestCycle.get().getMetaData(URL_VERSION);
---- > String calculatedVersion =
this.resourceVersion.getVersion(resource); < ------------
if (calculatedVersion != null &&
calculatedVersion.equals(requestedVersion))
{
response.setCacheDurationToMaximum();
response.setCacheScope(WebResponse.CacheScope.PUBLIC);
}
}
So the line marked above calls code that always creates a new session.
You can see the stack of this scenario below:
at
com.sas.av.ui.wicket.templates.WicketModelExposerApplication.newSession(
WicketModelExposerApplication.java:157)
at
org.apache.wicket.Application.fetchCreateAndSetSession(Application.java:
1569)
at org.apache.wicket.Session.get(Session.java:171)
at
org.apache.wicket.request.resource.PackageResource.getCurrentStyle(Packa
geResource.java:192)
at
org.apache.wicket.request.resource.PackageResource.getCacheableResourceS
tream(PackageResource.java:398)
at
org.apache.wicket.request.resource.PackageResource.getCacheKey(PackageRe
source.java:230)
at
org.apache.wicket.request.resource.caching.version.CachingResourceVersio
n.getVersion(CachingResourceVersion.java:100)
at
org.apache.wicket.request.resource.caching.FilenameWithVersionResourceCa
chingStrategy.decorateResponse(FilenameWithVersionResourceCachingStrateg
y.java:200)
PackageResource.getCurrentStyle() seems to be the culprit.
Does wicket really need to create a session when a static resource is
requested?
I hope the answer is no because I think the 6.12.0 approach worked well
because it did not create a new session for each static request from a
search engine.
Regards,
Chris
