Re: Re: Reasonably accurate timing

Normally that would be a good solution. Unfortunately, this script does the following:

Read in a (possibly) very large file and process it.
Process and plot data every minute.

The data from phase 1 is needed in phase 2. I actually plan on running the script from init...

Comment on Re: Re: Reasonably accurate timing

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Re (tilly) 3: Reasonably accurate timing by tilly (Archbishop) on Jul 24, 2001 at 08:51 UTC
I recommend mixing solutions. Run the script from a cron. However have the script first try to grab a lock, if it can then it is the only copy running so proceed. If it cannot then exit immediately. Basically the same idea as Highlander - allow only one invocation at a time of an expensive CGI script however exiting is to be expected. I believe that you will find this approach significantly better for dealing with sporadic problems (lost network connections, unexpectedly high load killing a script, needing to move the script and not losing fact of the detail that it is still in init, etc). It does not solve the problem at hand though.	[reply]

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Re (tilly) 3: Reasonably accurate timing
by tilly (Archbishop) on Jul 24, 2001 at 08:51 UTC

Run the script from a cron.

However have the script first try to grab a lock, if it can then it is the only copy running so proceed. If it cannot then exit immediately. Basically the same idea as Highlander - allow only one invocation at a time of an expensive CGI script however exiting is to be expected.

I believe that you will find this approach significantly better for dealing with sporadic problems (lost network connections, unexpectedly high load killing a script, needing to move the script and not losing fact of the detail that it is still in init, etc). It does not solve the problem at hand though.

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