[ckan-dev] Caching

Wed Mar 30 15:25:16 UTC 2016

I'm not sure why caching is disabled when variables are passed to the
templates. Seems like an oversight. Would you like to submit a patch
to remove that check?

On Wed, Mar 30, 2016 at 6:18 AM,  <Florian.Brucker at mb.karlsruhe.de> wrote:
> I did some further research in the caching logic in `render` in
> `lib/base.py`. It seems that in my case caching is always disabled due to
> the `extra_vars` being passed via parameter. These extra variables contain
> the data to be filled into the templates (e.g. the package information when
> displaying a dataset), and hence a change in these variables would
> invalidate a cached version of the template for the same URL (if we would
> allow caching in that case). From my research this kind of content-based
> cache invalidation (e.g. using an ETag-header) seems hard to do on the
> Nginx-level and should rather be done in the application (i.e. CKAN) itself.
> Although there seems to be some kind of page-caching built into CKAN (cf.
> the `ckan.page_cache_enabled` configuration option) it seems to respect the
> CKAN_PAGE_CACHABLE setting set by `lib.base.render`, which, as discussed,
> won't allow caching of pages when extra variables are set.
>
> So I guess my questions boils down to the following:
>
> - Does CKAN support caching of rendered templates? If not, are there any
> plans to add such a feature?
>
> - What benefit do I have from using Nginx in front of Apache + CKAN if Nginx
> will only cache static content?
>
>
> Regards,
> Florian
>
>
> "ckan-dev" <ckan-dev-bounces at lists.okfn.org> schrieb am 29.03.2016 17:20:56:
>
>> Von: Florian.Brucker at mb.karlsruhe.de
>> An: ckan-dev at lists.okfn.org,
>> Datum: 29.03.2016 17:21
>> Betreff: [ckan-dev] Caching
>> Gesendet von: "ckan-dev" <ckan-dev-bounces at lists.okfn.org>
>
>>
>> Hello everybody,
>>
>> I'm using Nginx as a caching proxy in front of Apache serving our
>> CKAN instance, as described in the CKAN docs [0]. Most things work
>> fine, however I've noticed that CKAN seems to add a "Cache-Control:
>> private" HTTP-header to all responses except static files, even if
>> the request does not come from a logged-in user. I do understand why
>> one might want to bypass the cache for logged-in users (as it's done
>> in the Nginx config example in the CKAN docs [1]), but why disable
>> (public) caching for the generated HTML for not-logged-in requests?
>> In my tests without a cache, page generation took much longer then
>> downloading all the static content, so caching the generated HTML
>> would make a lot of sense in my opinion.
>>
>>
>> [0] http://docs.ckan.org/en/latest/maintaining/installing/deployment.html
>> [1] http://docs.ckan.org/en/latest/maintaining/installing/
>> deployment.html#create-the-nginx-config-file
>>
>>
>> Regards,
>> Florian_______________________________________________
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>
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