[ZODB-Dev] what's the latest on zodb/zeo+memcached?

[Jim Fulton]

On Tue, Jan 15, 2013 at 2:08 PM, Claudiu Saftoiu <csaftoiu at gmail.com> wrote:
> On Tue, Jan 15, 2013 at 2:07 PM, Leonardo Santagada <santagada at gmail.com>
> wrote:
>>
>>
>>
>>
>> On Tue, Jan 15, 2013 at 3:10 PM, Jim Fulton <jim at zope.com> wrote:
>>>
>>> On Tue, Jan 15, 2013 at 12:00 PM, Claudiu Saftoiu <csaftoiu at gmail.com>
>>> wrote:
>>> > Hello all,
>>> >
>>> > I'm looking to speed up my server and it seems memcached would be a
>>> > good
>>> > way to do it - at least for the `Catalog` (I've already put the catalog
>>> > in a
>>> > separate
>>> > zodb with a separate zeoserver with persistent client caching enabled
>>> > and it
>>> > still doesn't run as nice as I like...)
>>> >
>>> > I've googled around a bit and found nothing definitive, though...
>>> > what's the
>>> > best way to combine zodb/zeo + memcached as of now?
>>>
>>> My opinion is that a distributed memcached isn't
>>> a big enough win, but this likely depends on your  use cases.
>>>
>>> We (ZC) took a different approach.  If there is a reasonable way
>>> to classify your corpus by URL (or other request parameter),
>>> then check out zc.resumelb.  This fit our use cases well.
>>
>>
>> Maybe I don't understand zodb correctly but if the catalog is small enough
>> to fit in memory wouldn't it be much faster to just cache the whole catalog
>> on the clients? Then at least for catalog searches it is all mostly as fast
>> as running through python objects. Memcache will put an extra
>> serialize/deserialize step into it (plus network io, plus context switches).
>
>
> That would be fine, actually. Is there a way to explicitly tell ZODB/ZEO to
> load an entire object and keep it in the cache? I also want it to remain in
> the cache on connection restart, but I think I've already accomplished that
> with persistent client-side caching.

You can't cause a specific object (or collection of objects) to stay
ion the cache, but if you're working set is small enough to fit in
the memory or client cache, you can get the same effect.

Jim

-- 
Jim Fulton
http://www.linkedin.com/in/jimfulton
Jerky is better than bacon! http://zo.pe/Kqm