[wpkg-users] frequency of wpkgservice checking for new installs

[Brad Langhorst]

On Tue, 2007-06-12 at 22:24 +0200, Tomasz Chmielewski wrote:
> Brad Langhorst schrieb:
> > On Mon, 2007-06-11 at 21:36 +0200, Tomasz Chmielewski wrote:
> > ...
> >>>>> okay - maybe i could add a feature to have it check periodically
> >> the
> >>>>> wpkg directory for a flag file telling it to initiate a sync?
> >>>>>
> >>>>> that way one could install software everywhere without having to reboot
> >>>>> or restart the service remotely.
> >>>> What do you mean by a "flag file"?
> >>> i mean a special file that an administrator could create to trigger a
> >>> sync.
> >>> eg: \\rococo\wpkg\FORCE_SYNC
> >>>
> >>> if the file is present when the service  polls the service could start a
> >>> sync.
> >> Well, it's not enough.
> >> So we create a file there, and don't remove it... What happens? We could 
> >> read some timestamps - what if the clocks are out of sync?
> >>
> >> So, we would have to check and remember timestamps - but what if WPKG 
> >> starts, and the file is already there?
> >>
> >> Yes, lots of "if"s :)
> > 
> > I'm thinking that if that file is there then the service will try to do
> > a sync every X minutes (which could be bad on a big network, but then
> > again a power outage could be bad too).
> > 
> > If the service just keeps syncing every X minutes then there are no
> > worries about timestamps etc.  If you wanted to do only a single forced
> > sync, I guess the service could keep track of whether it had synced or
> > not until it sees that the FORCE_SYNC file has disappeared (at which
> > point it could clear its already synced state and be ready to watch for
> > a new FORCE_SYNC file)
> 
> So, how do we determine X value?
> 
> Isn't a file which needs to be created an extra complication for the 
> administrator? Also, what if we want to synchronize only some selected 
> clients periodically?

> Maybe, just make an option in WPKG Client setup: do a synchronization 
> every X hours, or every day at HH:MM? Wouldn't it be duplication of a 
> System Scheduler?

The advantage of having a file on the server is that the admin does not
have to touch every machine (or use psexec) to get them all to sync up.
You bring up a good point about sets of machines...  That would be a
PITA to deal with using psexec too.

Maybe it's better to put this feature in the profiles.xml where it could
enabled be on a per group basis.

The value of X could be included as an attrib of the force_sync element
(or in the file) and could default to never.

I bet you could use the mac address of the nic to randomize the time
they sync up so you don't end up with bursts of activity. 

Brad


-- 
Brad Langhorst
CTO - CoopMetrics