Erik A. Dahl wrote at 2005-10-21 15:43 -0400: >> The ZODB cache lives in RAM and is a Python object cache. >> It is a per connection cache. >> >> The ZEO client cache lives on disk and is a pickle cache (it >> caches the object states not the objects themselves). >> It is shared by all connections to a single storage (in one process). >> >How do these two relate to each other?
You see a cache hierarchy: application world ZODB cache ZEO Client Cache ZEO Server (Python objects) (Python objects) object states object states The "ZEOClientStorage" fetches an object's state from its cache. In case of a cache miss, it fetches it from the ZEO server. The ZEO Client Cache can save you the network interaction. > Do I really need the disk >cache? I do not know... The ZEO developpers were convinced it were essential. They spent considerable time to optimize and tune it... Do you really care? Do you need to live with 1 GB disks (wide spread a decade ago)? > Can it be turned off? Sure, when you change the code. Otherwise, you can make it small but not turn it off. > I don't have "client" set so that each >process makes its own cache file. (When I set this I have problems >if two processes us the same zope.conf file). Is there a doc >somewhere explaining all of this?? "ZConfig" based software components (such as Zope and ZEO) provide valuable information in the configuration schema (usually found in files named "schema.xml" or "component.xml"; the Zope configuration schema is in ".../Zope/Startup/zopeschema.xml") A further valuable documentation source are the "docstring"s embedded in the source code. There are also documents around about the ZODB and ZEO (but I will not search them for you). -- Dieter _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev