Tollef Fog Heen
tfheen at linpro.no
Thu Jan 8 11:29:31 CET 2009
a short while before Christmas, I wrote up a small document pointing to
what I would like to get into 2.1 and when I'd like milestones to
happen. This is a suggestion, I'm open to ideas and comments on both
feature set as well as if my guesstimates for dates is completely off:
Varnish 2.1 release plan
The theme for Varnish 2.1 is "scalability", particularly trying to
address the needs of sites like finn.no which has a lot of objects and
where priming the cache takes a long time, leading to long periods of
higher load on the backend servers.
The main feature is persistent storage, see
for design notes. Another important scalability feature is a new
lockless hash algorithm which scales much better than the current
one. Poul-Henning already has an implementation of this in the tree,
but it's still fresh.
Minor features which would be nice to get in are:
* Web UI, showing pretty graphs as well as allowing easy configuration
of a cluster of Varnish machines.
* Expiry randomisation. This reduces the "lemmings" effect where you
end up with a many objects with almost the same TTL (typically on
startup) which then expire at the same time. The feature will allow
you to set the TTL to plus/minus X %.
* Dynamic, user-defined counters that can be read and written from VCL
* Forced purges, where a thread walks the list of purged objects and
- 2009-01-15: New hash algorithm working
- 2009-02-15: Web UI
- 2009-03-15: Persistent storage
- 2009-04-01: Feature complete
- 2009-05-20: Release candidate
- 2009-05-01: No release critical bugs left
- 2009-05-10: Release
Tollef Fog Heen
Redpill Linpro -- Changing the game!
t: +47 21 54 41 73
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