[wpkg-users] creative ideas to spread out the running of wpkginstalls?

[Mark Cooke]

-----Original Message-----
Sent: Thursday, July 19, 2007 9:46 AM
To: wpkg-users at lists.wpkg.org
Subject: [wpkg-users] creative ideas to spread out the running of
wpkginstalls?

<snip>

> One of the traps is that in order to make sure the wpkg installs get
> pushed out inside a reasonable timeframe, I opted to setup a scheduled
> task that restarts the wpkg service every two hours. Turns out that can
> be more problematic than I was expecting.

<snip>

Hi Urs,

The most obvious thing to me would be to use different offsets in your task
scheduling.  This could be done either with manually setting up different
groups of machines, or programmatically from inside wpkg.js

Example:

Divide your 2hr window into 4 30 minute sections, and configure a quarter of
the machines to synchronize every 30 minutes.  If your server doesn't cope
with 25% at once, then sub-divide further.

Take the last octet of the machine IP address and calculate:

 Delay = (last-octet % 4) * 30 minutes

Of course, you need to check that the IP addresses are well spread and that
it does balance the load sufficiently for your need.

To access the local IP from WSH, there's a sample function that parses up
ipconfig's output:
  http://www.jensign.com/JavaScience/www/wsh/IPInfo/getipname.html


Another option instead of basing the delay on the IP would be to just use a
random offset - on average your machines would spread the load.  However,
I'm not convinced that you could use Randomize/Rnd from WSH, because it
seeds itself from the current system time, and you're presumably using NTP
to keep your stations timestamps accurate.

Cheers,

Mark



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