Re: [Zope] Zope 2.8.4 strange behavior

Paul Winkler wrote at 2005-11-27 21:17 -0500:

... I've seen the same symptoms a number of times recently with zope 2.7.x. In our case, it seems to be related to ZEO. Zope seems to have lost its connection to ZEO but doesn't realize it somehow. My theory is that the symptom starts when all worker threads are waiting for objects that aren't in the ZEO client cache, so they're all waiting on ZEO requests.

Do you have a firewall between Zope and ZEO? Usually, the OS can inform both ends of a connection when the connection is torn down. However, some firewalls tear a connection down in a way that the endpoints do not get informed. We had to implement a keep alive mechanism to prevent our firewall from behaving in this nasty way. -- Dieter