That's interesting. Let me follow up with the team to try to understand how
this is supposed to work.

On Tue, Feb 2, 2010 at 12:05 AM, phraktle <[email protected]> wrote:

>
> Plus, it's working okay in the development server :)
>
> V.
>
> On Feb 2, 9:03 am, phraktle <[email protected]> wrote:
> > Hi,
> >
> > In this case grabTail would be quite useless, as one cannot really
> > construct queues with it (ie. it would just force removing items from
> > all namespaces that wouldn't even expire otherwise). The documentation
> > also implies that there's a separate LRU list per namespace, which
> > does make sense, but is not what's happening in production:
> >
> > http://code.google.com/appengine/docs/java/javadoc/com/google/appengi..
> .)
> >
> > "Grabs (atomically get and delete) items off the tail of LRU list.
> > This can be used to implement queue system with high throughput and
> > low latency, but low reliability. Current namespace should be set and
> > not empty for the service. For each namespace memcache maintains a
> > separate LRU list."
> >
> > Regards,
> >   Viktor
> >
> > On Feb 1, 9:22 pm, "Ikai L (Google)" <[email protected]> wrote:
> >
> >
> >
> > > I'll raise the issue with some other members of the team, but it seems
> like
> > > this is working as expected. A memcache namespace is nothing more than
> a
> > > prefix applied to a memcache key. There's no true partitioning
> mechanism
> > > within memcache. grabTail simply returns the item that would be expired
> by
> > > the LRU mechanism if memcache needed more space. There isn't a
> different
> > > "queue" per namespace, only a "queue" for global expirations.
> >
> > > On Mon, Feb 1, 2010 at 4:29 AM, phraktle <[email protected]> wrote:
> > > > Hi,
> >
> > > > On production, grabTail returns objects from other namespaces. This
> is
> > > > a significant problem that
> > > > makes grabTail (thus queue-like usage) unusable.
> >
> > > > I filed this as a bug, with a very simple example here:
> > > >http://code.google.com/p/googleappengine/issues/detail?id=2706
> >
> > > > Can you please look into this? I don't even see a workaround that I
> > > > can implement in the meantime...
> >
> > > > Thanks,
> > > >  Viktor
> >
> > > > --
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> [email protected]>
> > > > .
> > > > For more options, visit this group at
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> >
> > > --
> > > Ikai Lan
> > > Developer Programs Engineer, Google App Enginehttp://
> googleappengine.blogspot.com|http://twitter.com/app_engine
>
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>


-- 
Ikai Lan
Developer Programs Engineer, Google App Engine
http://googleappengine.blogspot.com | http://twitter.com/app_engine

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