[ZODB-Dev] Re: [Enhancement Proposal] Memory size limited Cache

[Tres Seaver]

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Jim Fulton wrote:
> Dieter Maurer wrote:
>> Jim Fulton wrote at 2006-10-6 12:21 -0400:
>>> ...
>>>> We would have a use case for this, too.
>>> We've started moving toward just using a single application thread
>>> per process
>>> (with many processes).  There isn't really much advantage in running
>>> multiple
>>> threads if you have multiple processes. 
>>
>> Apart from sharing resources, such as the cache....
> 
> That isn't a benefit of multiple threads.  It is a way to
> mitigate the cost of multiple threads.  In the presence of the
> GIL there is no throughput benefit in running multiple threads.
> The only benefit of multiple threads is that it is somewhat
> less likely that expensive requests will block inexpensive ones.

Assuming that you aren't disk or RAM constrained, I'll agree that
running multiple processes is more likely to win, especially on
multi-CPU machines.  However, most sites which have such needs might do
better to have a single, *large* cache, than many smaller ones;
swapping will kill any benefit obtained from better parallelism.


Tres.
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Tres Seaver          +1 202-558-7113          tseaver at palladion.com
Palladion Software   "Excellence by Design"    http://palladion.com
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