[Ovirt-devel] Re: [PATCH] Use multiple processes to check host status

[Ian Main]

On Fri, 13 Jun 2008 14:38:16 -0700
Ian Main <imain at redhat.com> wrote:

> This patch causes host-status to fork() up to node_count/5 times to
> connect out to hosts via libvirt.  This guarantees that that it takes at
> most 5 timeouts in a row to verify all nodes.  This should help with the
> bottleneck we were seeing with libvirt connect timeouts.  Testing with 105
> nodes, almost all of which were down, it took 27s to query all of them.

Hmm, I got to thinking.. with all of the nodes on that system it was already established that there was 'no route to host' so the timeouts were quick.  A freshly killed node would take longer to timeout.  We could set the process count higher to help eliviate this.  However, I see that it can take up to 10 minutes to timeout a connection under certain circumstances.. 

It's clear we should move to having the status pushed from the node to the wui, then timeouts will only be a problem for operations in taskomatic etc.  We may want to add a timeout to the libvirt API to deal with this at some point..

    Ian