Re: Mass Mailout Performance Tips - The Diigo Meta page

• 06 Mar 08
  

  Joel Liu

  mass performance qmail

  • There is a qmail patch (big concurrency) that will allow running more remotes. The default kernal in RedHat 6.1 limits you to 512 total processes and half that per user. I have recompiled the kernel for 2560 total processes and 2048 per user. See the file /usr/src/linux/include/linux/tacks.h.
  • I can get about 50K emails per hour using 400 remotes. That would take 10 hours with your list. The qmail queue size seems to stabilaze between 10K and 15K during the run. There is usually between 300-400 remotes running.
  • I am currently experimenting with bypassing qmail altogether. Using shared memory I fork off 1000 child processes to chew on a list in parallel. Each child will call qmail-inject only if its direct attempt fails. My testing is still rough but it looks like I can get a 5 to 10 fold improvement.

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