Feedback on Tag Support
dormando
dormando at rydia.net
Fri May 9 18:07:53 UTC 2008
On skimming the code it looks like tag invalidating loops over all items
and removes them from a linked list, then removes the tag from the splay
tree.
-Dormando
Jonathan Ariel wrote:
> It doesn't seems to be a loop, it says "We use hash and splay tree, make
> the tag_add and tag_delete commands very quickly, and save memory as
> much as possible."
>
> On Fri, May 9, 2008 at 2:44 PM, Dustin Sallings <dustin at spy.net
> <mailto:dustin at spy.net>> wrote:
>
>
> On May 9, 2008, at 9:52, John Kramlich wrote:
>
>> Is anyone using the variant of memcached v 1.2.4 that supports
>> tagging found at the following
>> URLhttp://code.google.com/p/memcached-tag/ ? I am in the planning
>> stages of major feature additions to my web application and would
>> really like to use this version. I'm looking for feedback from
>> others who have used it. Is it stable enough for production use?
>> Any issues?
>
> I think tagging is a generally useful feature, but we honestly
> haven't put a lot of effort into reviewing the tag code.
>
> In particular, we want tagging to be cheap on both setting and
> invalidating. If either operation has to perform more than a single
> lookup, then it may not be desirable. In particular, deleting by
> tag is a loop (within a lock and with another nested loop within
> it), which may cause the server to hang for long periods of time
> when invalidating a widely-used tag. It *should* be possible to do
> this without such a loop.
>
> --
> Dustin Sallings
>
>
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