[pmwiki-users] PmWiki scalebility questions (newbie)

[Tom Lederer]

Thanks for the enlightenment. Assuming that indeed a recipe causes  
the locks: can anybody tell me how to look for the right terms to  
find the recipes that use the flock?

I.e. is it a special php function that i can grep for?

Best Regards,
Tom
-- 

Tom
http://www.celok.de


Am 19.10.2006 um 14:52 schrieb Patrick R. Michaud:

> On Thu, Oct 19, 2006 at 02:16:00PM +0200, Tom Lederer wrote:
>> i kinda re-open this thread. Having a relatively large wiki (wiki.d:
>> 33 MB in 5000 pages, Version 2.1.11 (Doh!)) running and facing some
>> performance issues lately, we think we discovered a problem with the
>> flock file. So i would like to know if we are correct and how to
>> improve.
>>
>> From what we learned the situation seems to be like this:
>>
>> Every page access process sets a read lock (with flock). Now if a
>> page should be changed, the writing process needs to wait for all old
>> reading processes to end, and does not allow any new reading
>> processes to set a lock.
>
> While PmWiki once worked this way a very long time ago (April 2005,
> prior to 2.0.0), it doesn't any longer.  Simply reading or
> accessing a page doesn't require a lock -- locks are set only
> when writing a page.
>
> So, if a page should be changed, the writing process only needs to
> wait for any other writing processes to end, and none of the
> read processes are blocked.
>
> (Of course, a recipe might be misusing the lock file and setting
> a read lock on every page access, but the PmWiki core doesn't
> do this.)
>
>> Is it possible that this results in page request times of several
>> seconds (1-30)?
>
> Not likely.  There must be something else that is causing the delay.
>
>> Can performance be improved by introducing per-group lock files?
>
> Per-group lock files don't really help here -- whenever a page
> is saved, we're actually writing pages across several groups
> (e.g. Site.AllRecentChanges, .pageindex, .notifylist), and this
> will only increase once we add some of the commenting and
> blogging features.
>
> Pm
>