[Server-devel] [UKids] Server Backup on HaitiOS

[James Cameron]

On Tue, Jun 17, 2014 at 03:52:05PM -0400, Richard Smith wrote:
> On 06/16/2014 06:46 PM, James Cameron wrote:
> >
> > (In my opinion a more correct solution is to change ds-backup to
> > not need ping, but instead attempt the backup anyway.  This would
> > avoid failing a backup if ping could not be run.)
> 
> I have a vague memory of Martin telling me why the ping test was
> there but I can't quite pull it up.  Perhaps there are some issues
> with rsync when the machines are not reachable like a long timeout
> or something?

Quite a long history there, goes back to 8.2.1 and earlier, when Ivan
was ds-backup maintainer.

Yes, there were such issues, but they were in the tools, not in
ds-backup.  They were since fixed, but we haven't gone back to test,
to force the various scenarios of network loss.

Network actions by ds-backup are an HTTP GET first, then an rsync.

The HTTP GET had no timeout coded, so Python's urllib2 would have been
to blame.

The rsync had a data timeout coded, but had a very long connect
timeout once upon a time.

The need for caution was because this script was to be run every time
the interface comes up, and every 30 minutes.  Laptops on the boundary
of coverage would run the script repeatedly.  Now it is only run every
15 minutes as a systemd task.

While the sudo looks fine, in my experience it is a heavy cost, which
an "strace sudo true" exhibits.  It is suddenly not lightweight.

And, irritatingly, still no GUI for a user to start a backup?  ;-)

Your fixed RPM for 12.1 was released on server-devel@ on 1st April 2013,
http://dev.laptop.org/~rsmith/ds-backup-client-0.15-1.fc17.noarch.rpm
and perhaps that is what the HaitiOS guys could use in their next spin?

-- 
James Cameron
http://quozl.linux.org.au/