[Zope-dev] Zope Head (2.8) breaks "refresh"

[Jeremy Hylton]

On Sun, 2003-12-14 at 16:53, Chris McDonough wrote:
> > We still use ZODB 3.1 and at least there, the cache verification
> > protocol seems quite stupid. We will soon switch to ZODB 3.2
> > and when cache validation still needs minutes, I will need
> > to look into this...
> 
> Apparently, the ZEO in 2.7 and the HEAD is better about doing as little
> work as possible for cache verification at startup than older versions
> were.

Specifically, the server saves the list of invalidated objects for the
last N transactions and the client keeps track of the last transaction
id it received an invalidation for.  One restart, if the last txn the
client saw was within N of the current transaction, the server just
sends the list of invalidated objects.  For a large cache, this is much
cheaper than having the client send the oid and serialno of every object
in the cache to the server.

N is configurable.  I think the default value is 100.

Jeremy