[Tres Seaver]
... A minutes-long startup is likely due to the client's need to verify a large persistent disk cache; one workaround would be to turn off persistent caches; a longer-term solution would be to work with the folks on zodb-dev to land a set of improvements to the cache verification code (they live on a branch somewhere, I think).
All the cache verification speedups we had were released in ZODB 3.2 (see primarily "What's new in ZODB3 3.2 alpha 1" in http://zope.org/Products/ZODB3.2/NEWS ). There aren't any more of those hiding on a branch. There are other kinds of optimizations hiding in assorted branches, though. Having a "large" persistent ZEO cache has opposing effects: (a) possibly better steady-state performance; (b) guaranteed longer cold-start verification time. That tradeoff is unavoidable with the current design. A possible future direction may be to use much larger ZEO caches, but to weaken the meaning of "persistent" by simply giving up after verification has consumed N seconds (throwing away all cached objects that haven't managed to get verified by then). There's no code anywhere to do that now, though.