On Sat, 3 Apr 2010 17:02:38 +0400
Raghavendra G <
address@hidden> wrote:
> On Fri, Apr 2, 2010 at 5:49 PM, Stephan von Krawczynski <
address@hidden>wrote:
>
> > On Fri, 02 Apr 2010 14:41:36 +0100
> > Gordan Bobic <
address@hidden> wrote:
> >
> > > On 02/04/2010 12:32, Olivier Le Cam wrote:
> > >
> > > > Following to a recent talk on the IRC channel, it came to my mind that
> > > > caching lookups could (in this particular situation) greatly improve
> > the
> > > > performances.
> > >
> > > Maybe some of the devs can explain whether this is plausible, but I
> > > somewhat doubt it. You would lose the integrity guarantees.
> >
> > If you're talking of data integrity here I doubt that it is there at all.
> > Yesterday I checked a configuration with 2.0.9 replication and 3 clients
> > with
> > iocache. I found out that if I edit an ascii file on one client and save it
> > back being the same size as before, another client still sees the old file
> > content. I checked the servers and found that they all contained the
> > correct
> > new file version. So the data integrity is broken anyway when using iocache
> > on
> > clients
> >
>
> This is quite expected, since the client on which the data is being read has
> cached the data. io-cache has cache-timeout option which can be tuned to
> force the clients to check whether the file has changed on server after
> configured time intervals.
>
> However also please note that, if the file is being modified and read from
> the same client, this issue would/should not have happened.