[mod_cluster-dev] Session temporarily unavailable
paul.ferraro at redhat.com
Wed Jul 22 09:53:04 EDT 2009
On Wed, 2009-07-22 at 09:37 -0400, Brian Stansberry wrote:
> If you shut down node 1 cleanly, it should be telling httpd itself that
> it's gone.
Or, if using HAModClusterService, and node2 was the HA singleton master,
node1 will tell node2 to tell httpd that node1 is gone...
> Bela Ban wrote:
> > When I have 2 nodes (node1, node2), and a session which is created on
> > node1 (and replicated to node2), the following can happen:
> > * I shut down node1 (CTRL-C)
> > * node1 terminates cleanly
> > * I access the webapp, but get a "Session temporarily unavailable"
> > failure message (I guess a 500)
> > * When I check mod-cluster-manager, information about node1 is still
> > there !
> > * Ca 5 seconds later, mod-cluster-manager doesn't show node1 anymore
> > * When I now access the webapp, I get the proper failed over session
> > on node2 and all my data is still there
> > So my question is why doesn't node2 immediately tell httpd/mod-cluster
> > that node1 is gone ? It seems that httpd *itself* only learns about this
> > when it pings the socket to node1...
I should be. Do you see the appropriate STOP_APP, REMOVE_APP messages
in your httpd access log?
> > I recall Paul once telling me we hadn't implemented that functionality,
> > but I guess by now this is surely implemented ?
I never said that, but I think I know of the conversation to which you refer...
If you are running mod_cluster via HAModClusterService and node1 crashed
(instead of a clean shut down), node2 will not send any MCMP messages to
httpd on behalf of node1 when it receives a view change.
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