Re: [BackupPC-users] killing backuppc job after client disconnects

Hi,

Marcelino Mata wrote on 2009-09-18 13:47:03 -0400 [[BackupPC-users] killing 
backuppc job after client disconnects]:
> I have been testing backuppc for a few weeks with a dozen Windows
> laptops.  I have chosen smb over rsync protocol for it's setup
> simplicity and it's working well for what I need. [...]
>  
> One outstanding problem is that when a Laptop user disconnects from the
> network, backuppc never terminates the backup job. [...]
>  
> Is the preferred solution to change the ClientTimeout value or is there
> another solution to address this?

Yes :-). Yes, you should change the ClientTimeout value - that's what it's
there for (to abort "hung" backups).

> If this is the preferred solution, it seems to me that 20 hour timeout
> is very long time.  I would like to change it to 4-6 hours hours but I
> would think the 20 hour value was chosen for good technical reason?

The default used to be 2 hours, but there were frequent problems for new users
caused by erroneously aborted backups. The problem about ClientTimeout is that
it is not strictly a timeout in the sense of "when nothing happens for X
seconds ...". It's more like "when the process monitoring the timeout doesn't
get any progress reports for X seconds ...", and that depends on XferMethod.
If I'm not completely mistaken, for rsync, there are *no progress reports* for
the whole of the backup, meaning ClientTimeout must accommodate for the longest
backup. For tar/smb backups, I believe there's a progress report for each file
received, meaning ClientTimeout needs to accommodate for the transfer time of
the largest file. That might be difficult to anticipate ahead of time, but it
may give you a lot of room for decreasing ClientTimeout (and you can set it on
a per-host basis).

The rationale behind raising the default value of ClientTimeout to 20 hours
is probably that keeping hung backups around for a long time is inexpensive,
which obviously doesn't apply in your case:

> As the smbclient process jumps to 100% when this condition occurs, [...]

I'm not sure why that happens, but it doesn't tend to be something you *like*
happening for a long time (even 15 minutes). You would be better off to fix
that problem (has anyone got a tip on that?). You might still want to lower
ClientTimeout, but you'll run into problems with large files if you set it
too low, and you'll be forced to set it as low as possible if you can't fix
the smbclient problem.

Regards,
Holger

------------------------------------------------------------------------------
Come build with us! The BlackBerry&reg; Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay 
ahead of the curve. Join us from November 9&#45;12, 2009. Register now&#33;
http://p.sf.net/sfu/devconf
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List:    https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki:    http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/