Re: [PATCH 0/8] Domain Groups: Introduction

["Daniel P. Berrange" <berrange@redhat.com>]

On Tue, Feb 20, 2007 at 02:55:33PM -0500, Chris wrote:
> This patchset allows the user to define and manage groups of domains.
> The patch augments the xm utility with the following commands:
> grp-create, grp-shutdown, grp-destroy, grp-reboot, grp-pause,
> grp-unpause, grp-save, grp-restore, grp-join, and grp-migrate.
> 
> A goal during development of group operations was to match support for
> common domain operations: create, shutdown, destroy, reboot, pause,
> unpause, save, restore, and migrate.  Their group-specific counterparts
> do what you would expect, but operate on a group of domains instead of
> on a single domain.

What is the error handling policy ? eg, if 'save' fails will it just
skip over that domain and save the rest, or will it abort and restart
the ones it had saved upto that point, or just abort ? Likewise for
the other group operations

> 2. Operation ordering: it is advantageous to guarantee the order of
> group operations.  A practical example is to ensure that the group's
> database server is always running before and after the group's web server.

This somewhat ties into my question on error handling above, but also
raises the question of how do you know whether the DB server has completed
booting far enough to be able to start the web server. The latter seems a
pretty much impossible question to answer reliably unless you've got
some notification from the app inside the guest to say it is ready to
serve. 

Regards,
Dan.
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