rack-cache Google Group

Using Rack::Cache to serve static versions of dynamic pages (ala rails page caching)

bod...@gmail.com (Mike) — Thu, 07 Jun 2012 20:25:19 UT

Im using ruby 1.9.2, rails 3.1.3 on Heroku Cedar.

I want to use Rails page caching and Im looking for a technology that
will look for the cached version of a page and serve it directly if it
exists (in the cache) or otherwise forward to the rails component.

To do this I need a way to tell rack::cache to map the incoming URL

Re: Meta-cache Performance

mailing_li...@bengreenberg.net (Ben Greenberg) — Sat, 28 May 2011 18:54:47 UT

Thanks for the replies. This is on Amazon EC2 with the stores on an
EBS volume. So EBS itself is probably a bottleneck. I think that you
nailed it with the tmpfs suggestion; this will allow me to move my
meta-cache into RAM without having to regenerate everything.

Thanks
Ben

Re: [rack-cache] Meta-cache Performance

r...@tomayko.com (Ryan Tomayko) — Fri, 27 May 2011 05:30:45 UT

Yes. The metastore cache will need to fill in but the disk cache
should not be rewritten.
I think it would result in each of the cached URLs being generated by
the app in full once, even though the response won't need to be
written to disk. It's hard to say how much this will impact your app's
performance. If a relatively small percentage of URLs are being hit

Meta-cache Performance

schna...@gmail.com (Ben Greenberg) — Fri, 27 May 2011 04:50:54 UT

Hi all,

I'm using rack-cache in front of an image generation server. My cached
files are large (images) so I currently write both caches to disk. I
read that I can increase performance by putting the meta cache onto
memcached. The problem is that I already have many gigabytes cached;
the meta cache is currently about 1GB and I expect it to grow quite a

Re: [rack-cache] Storage instances

r...@tomayko.com (Ryan Tomayko) — Thu, 26 May 2011 21:35:48 UT

Yes. I'd definitely like to support custom stores at some point. Right
now you can achieve this by adding a constant to
Rack::Cache::MetaStore::REDIS and Rack::Cache::EntityStore::REDI S
pointing to the implementation classes. I'd like to add a cleaner API
sometime in the future.
Also, I'd accept a patch to add Redis meta and entity stores for sure.

Storage instances

twarl...@gmail.com (Travis Warlick) — Thu, 26 May 2011 20:58:29 UT

I would like to use a Redis::Distributed instance for the metastore;
however, since rack-cache.metastore only supports URIs, I'm wondering
if this was an intentional design decision and if a concept like this
could be successfully merged into that design:

use Rack::Cache, :metastore =>['redis://redis1/0', 'redis://

Re: [rack-cache] cache cleanup

aidan.feld...@gmail.com (Aidan Feldman) — Mon, 23 May 2011 14:52:27 UT

Sorry, I mean tmpreaper<[link]>
(which
is similar).

Re: [rack-cache] cache cleanup

aidan.feld...@gmail.com (Aidan Feldman) — Mon, 23 May 2011 14:12:36 UT

For anyone else who is interested, we ended up using
tmpwatch<[link]>,
which allowed us to remove the least-recently accessed files.

Re: [rack-cache] cache cleanup

r...@tomayko.com (Ryan Tomayko) — Wed, 18 May 2011 03:46:46 UT

The metadata and blob's timestamps can get out of sync but if you
remove a blob, the next cache hit will detect that it's gone and treat
it as a miss, cleaning up the metadata along the way. It's not a
perfect system (you can end up with blobs or metadata files that have
aren't paired properly) but it's very simple and should work fine for

Re: [rack-cache] cache cleanup

aidan.feld...@gmail.com (Aidan Feldman) — Wed, 18 May 2011 03:04:33 UT

Wow, that is so much simpler than the script I was writing (reading the
metadata and deleting the N oldest files...) So the metadata file doesn't
get updated on access, right? Therefore this would delete both the metadata
and the blob?

Re: [rack-cache] cache cleanup

r...@tomayko.com (Ryan Tomayko) — Mon, 16 May 2011 20:19:52 UT

Sorry for the late response!
This currently requires a manual / external process. I'd recommend
setting up a cronjob that runs something like:
find /var/cache/rack -type f -mtime +5 | xargs rm -f
That will delete any entries that have not been served for more than five days.
The disk stores are designed to allow individual files to be removed

cache cleanup

aidan.feld...@gmail.com (Aidan Feldman) — Thu, 28 Apr 2011 22:00:59 UT

Hi all-
So I am using a rack-cache Disk store in an image processing application I
built <[link]>, which creates new cached
resources based on URL query params. As there are a potentially infinite
number of combinations and values of these params, the cache can grow
without bound and leave lots of potential abandoned resources. I would like

Change caching for a specific page

avl...@gmail.com (Andrew vonderLuft) — Thu, 14 Apr 2011 18:53:09 UT

In rails, how would you override the max-age for a specific page?

Re: [rack-cache] quastion about keys

r...@tomayko.com (Ryan Tomayko) — Sun, 20 Feb 2011 09:18:25 UT

That value is typically set when you use the Rack::Cache middleware in
your config.ru:
use Rack::Cache do |options|
options.set :cache_key do |request|
...
end
end
The full list of options is defined here:
[link]

quastion about keys

jsilva.jc...@gmail.com (tonio) — Mon, 07 Feb 2011 22:12:05 UT

Hello everyone,
I loved rack-cache from the very first time that I used it, but now I
have a more complex requirement...
My app has a cookie with two important values: lang and country_code.
This values are similar to many people, but I need to cache
separately, because if I don't do it all the visitors see the site in