invalidating (ban) a cache problematically, real life maximum?

Per Buer perbu at
Wed Oct 10 14:59:04 CEST 2012


On Wed, Oct 3, 2012 at 9:31 PM, S Ahmed <sahmed1020 at> wrote:

> I was reading:
> My main question is, what sort of # of ban requests can one realistically
> send to varnish to invalid caches? (individual items, not ranges etc.)

I would limit bans to maybe 10-30 per second, no more. Make sure they are

Say a site like tumblr is using varnish, which has thousands and thousands
> of blogs, and so many blog entries are being updated via comments etc.  How
> realistic would sending 1K ban's be to varnish?

Sending 1k purges to Varnish would be no problem at all. Bans - I'm not
sure that is a good idea.

> Maybe I have misunderstood this, but I'm guessing their are ruby/java
> client libraries that when content gets updated in a web application, I
> could then send a request using the ruby/java client library to ban a
> specific item from cache right?
> If there are client libraries, where can they be found?  I'm looking for
> both ruby and java.

It might make sense to implement it yourself. It is dead simple and you
don't need the complexities of a generic library.

Per Buer
Phone: +47 21 98 92 61 / Mobile: +47 958 39 117 / Skype: per.buer
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