question regarding memory usage

[Evert | Rooftop]

Bill Marcum wrote:
> I'm considering using memcached for our php application.  We have certain large objects we retrieve on almost every request, and I'd
> like to optimize the retrieval and the memory required to load these objects every time.  I see the following on the site:
>
>   
>> The first thing people generally do is cache things within their web processes. But this means your cache is duplicated 
>> multiple times, once for each mod_perl/PHP/etc thread. This is a waste of memory and you'll get low cache hit rates. 
>>     
>
> My question: since most requests retrieve these objects, isn't it true that I'm still going to duplicate the object multiple times, once
> for each PHP thread?  All I'm doing is replacing a mysql call with a memcached call.  
>
> I'm thinking that what I really need is a PHP module that supports synchronized read/write access to a single memory object from  
> multiple threads.  But I don't see any PHP modules out there that appear to do this.
>
> Am I missing the point here?
>
>
>   
Memcache only starts to make sense when you make use of multiple boxes. 
If you are dealing with just one box I'd absolutely recommend APC for 
caching instead.

Evert