[Zope-dev] Streaming Response

Johan Carlsson [EasyPublisher] johanc@easypublisher.com
Thu, 24 Apr 2003 13:15:33 +0000


At 09:04 2003-04-24 -0400, Casey Duncan said:

> >
> > Deactivating *every* block looks like a bad idea. This defeats the 
> in-memory
> > cache that will be a big win for small files.
>
>I agree.
>
> > The memory cache is only a disadvange if your files are large enough that
>they
> > have enough chunks to disrupt LRU cache policy. How about comparing the
> > number of chunks to a fraction of the cache target size?
>
>I think possibly a better solution is to have an explicit switch on the file
>like "Disable ZODB caching (recommended for large files)" so that it can be
>decided as policy on a case-by-case basis.

In the case of the explicit configuration option, wouldn't it be good to
use a file-based caching mechanism instead?
In other word write the unpickled blocks to a cache file and stream that
file to the response.

I'm not sure what the overhead for reading data from the ZODB is, but
I suspect streaming large files could be a bottle neck.

Cache-files could be removed when the database is flush or packed.

Best Regards,
Johan Carlsson



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Johan Carlsson
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