Results 1 to 6 of 6
  1. #1
    Join Date
    Mar 2004
    Location
    Singapore
    Posts
    6,984

    Definitions and Advice on Qmail Queuelifetime

    Quelifetime defines the amount of seconds a message stays in the queue. Standard default is 604800s. Can I know if we set longer or shorter, will it affect CPU, Bandwidth, Memory I/O utilisation?

  2. #2
    Join Date
    Apr 2003
    Location
    Los Angeles, CA
    Posts
    800
    Qmail has a "quadratic" retry schedule, meaning that old messages are retried less often. So if you increase your queuelifetime, the messages will just stay longer in the queue and will be tried more times before they are finally bounced.

    Does it use:
    1) Bandwidth -- yes, a bit, because on each retry qmail tries to establish the connection and send the message. Adds up when you have 1000s of messages. TCP overhead is counted at the switch by your DC.

    2) CPU -- somewhat, because the more messages there are queued, the more overall attempts will be required and each attempt uses some CPU. Again, if you have 100 messages queued, not a problem. If you have 100K, it makes a difference.

    3) Memory I/O -- related to CPU, really. Queued messages do not stay in RAM, but the I/O increases because of re-reading the messages on delivery attepts, and due to writing the log files. A delivery attempt is just another thing to do for your server.

    4) Disk space -- i-nodes and space are consumed by messages in the queue. Only something to worry about if you have a small drive or full drive.

    Hope this helps...
    Last edited by luki; 04-28-2004 at 10:25 PM.
    Pings <1 ms, Unlimited Transfer, Lowest Price: http://localhost/

  3. #3
    Join Date
    Mar 2004
    Location
    Singapore
    Posts
    6,984
    Yes thanks , really need the point format of your explanation really clears up my mind. Prob is what is the Optimium, I read Dave Sil book but he doesnt really have a real figure......I am afraid if I put the time as too long , the msg may be delivered far too late. Would be a prob if it is time critical, rather than it bounce earlier to the sender so that they can attempt again......

  4. #4
    Greetings:

    We have ours set to two days. That has worked well for us for over a year now.

    Thank you.
    ---
    Peter M. Abraham
    LinkedIn Profile

  5. #5
    Join Date
    Mar 2004
    Location
    Singapore
    Posts
    6,984
    But 2 days my queue will be about 1k plus. Would that be too many?

  6. #6
    Greetings:

    The default quelifetime is seven days.

    If you are using the default and change to two days, then you will lower your queue by five days.

    Too many, there are too many unknowns to answer. I can only state that if you are using the default, two days will be better presuming most of your clients have services which are not down for more than two days.

    Thank you.
    ---
    Peter M. Abraham
    LinkedIn Profile

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •