[Grok-dev] Re: Apache support for Grok
faassen at startifact.com
Tue Jan 16 08:59:27 EST 2007
Laurence Rowe wrote:
> Well as I have looked into this fairly recently perhaps this summary can
> PGStorage is a full ZODB storage (supporting undo and packing but not
> zodb level versions, which no one uses anyway). It also replaces the ZEO
> layer. It subclasses the connection to provide per thread connections.
> This means that it replaces ZEO and MVCC is performed by postgresql. It
> stores pickles in the database so is conceptually fairly simple. It
> depends on Postgres 8.1 or later.
> Performance considerations (this is based on gut instinct rather than
> * ZEO performs conflict resolution on the ZEO server rather than the
> ZEO client. As far as I know only ZODB BTress have conflict resolution
> code. This could be a problem for PGStorage in high concurrent write
> situations where network latency could become an issue.
> * PGStorage leverages the postgres networking layer which (according to
> pgstorage.sf.net) gives it an edge against ZEO + FileStorage in simple
> I'm not aware of any production use of PGStorage.
Cool; thanks for the summary - I only just saw it! So it looks like
PGStorage would be a good candidate to try for an Apache version of Zope
I wonder how much it depends on PostgreSQL specific features;
unfortunately most hosting setups offer MySQL.
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