I have a perl based mail filter that runs on one account (that gets a ton of spam). I would like to keep the # of concurrent runs of this filter down.

I do not want to do this in the qmail since it would restrict the rest of the site for # of concurrent deliveries.

What I'm thinking about is some way to check how many copies of the script are running and if it is > x then wait until it is <= x and then continue to process.

Some possibilities are checking the process list (but that could cause multiples to still start running at the same time) or writing a file out at start of processing and deleting it at the end (but what if the removal fails, then maybe check a timestamp).

People do this with pid files quit often, but I'm not sure of the best way to process them.

Has anyone ever had to restrict # of concurrent processing copies of a program? What have you done? What has worked? What hasn't? Did you setup queues?

Thanks for any ideas.

W

In reply to Maximum # of concurrent runs by warthurton

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