Good question! In my opinion, invalidating cache entries is an essential operation of a cache. Varnish already supports HTTP PURGE without a separate process, so invalidating entries is supported in Varnish directly. What is not supported directly is invalidating entries across a cluster. This requires listening on a separate port, but that doesn't seem like a very strong reason for breaking the functionality into a separate program.
It also seems as though keeping the code for HTCP alongside the rest of Varnish will promote maintainability. Adding this to Varnish proper should lead to a good start for supporting the other operations in HTCP, specifically the ability for a server to query its peers to determine whether they have a cached representation available. Furthermore, Squid supports HTCP out of the box, so feature parity in this area will make it easier to gain market share. Thoughts? -Benjamin On Jul 6, 2011, at 10:44 AM, Per Buer wrote: Hi, Why should this be in Varnish directly? Whats wrong with having it in a separate program? Per. On Wed, Jul 6, 2011 at 4:38 PM, Ben Truitt <[email protected]<mailto:[email protected]>> wrote: I was able to find the location of the source code for the HTCP plugin I referred to in the below email (thanks, Artur Bergman): https://svn.wikia-code.com/utils/varnishhtcpd/ I'm still curious to know whether there are any plans to incorporate this or similar functionality for purging a clustered cache into Varnish going forward. Thanks, Benjamin On Jul 5, 2011, at 4:56 PM, wrote: > Hi - > Thanks for the great work on Varnish! > > My team at Rackspace is considering adopting Varnish for some RESTful > services we're creating. We're planning to have a cluster of reverse proxy > cache servers in front of our origin servers. One of the issues that is > important to us is the ability to keep the cache consistent with the origin > server's data store as much as possible. > > I realize that Varnish supports HTTP PURGE operation, but we'd prefer to use > something like HTCP's CLR operation for a multicast purge. I came across a > fairly old varnish-dev mailing list item related to this: > > http://www.mail-archive.com/[email protected]/msg00315.html > > That post indicates that HTCP CLR would be incorporated into Varnish, but I > don't see that it has been. > > I'd love to know: > 1) Are there plans to include HTCP CLR in Varnish any time soon? > 2) Is there a plugin (such as the one Artur Bergman created) available that I > can use today? > > Thanks in advance for your time! > > Best, > Benjamin Truitt This email may include confidential information. If you received it in error, please delete it. _______________________________________________ varnish-misc mailing list [email protected]<mailto:[email protected]> https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc -- [http://www.varnish-software.com/sites/default/files/varnishsoft_white_190x47.png] Per Buer, CEO Phone: +47 21 98 92 61 / Mobile: +47 958 39 117 / Skype: per.buer Varnish makes websites fly! Whitepapers<http://www.varnish-software.com/whitepapers> | Video<http://www.youtube.com/watch?v=x7t2Sp174eI> | Twitter<https://twitter.com/varnishsoftware> This email may include confidential information. If you received it in error, please delete it.
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