Messages in this thread | | | Subject | Re: System resource useage abnormalities | Date | Thu, 1 May 1997 13:22:51 +0300 (EET DST) | From | Matti Aarnio <> |
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> Qmail was running just fine on my P133, but that machine had to go away > and I installed qmail and SmartList on my 266Mhz UDB Alpha. The kernel is > 2.0.27 and distrib RedHat 4.1. This machine isn't one of those great > powerhouse Alpha's, but it should be a little better than a P133. Instead, > I am finding that the load average is unusually high and the system > somewhat slow in delivering mail for no good reason. Here's a typical view > from top.
It is not about your host performance... ... > A very dead system. Nothing unusual happening. Minimal interrupts/second > and context switching. But there's a high load average with 60% cpu idle > time. The top just didn't happen to catch the cpu while waiting on disk, > it's averaging 60%. I'm sending lots of mail through the mailing list. > It's on cablemodem now as opposed to T1 when I had the list on the P133. > Not sure how this would cause such a high load with low cpu useage.
The cablemodem has fairly fast channel from the network to your machine, but SLOW link the other way. (64-200 kbps)
Part of the problem is that Qmail sends all smtp sessions in parallel, which effectively kills your already meager outbound bandwidth (and your machine). "In parallel" meaning: For each recipient address on EACH message it runs individual smtp transporter process. You have 10 messages with 20 addresses --> you have 200 smtp transporters running...
> Anyone have any ideas?
You need to have a T1 connected service provider that is willing to do the actual distribution of the smtp messages. Then you define message routing so that all non-local traffic is sent to that server.
> ---------- > Tracy Reed > http://www.ultraviolet.org
/Matti Aarnio <matti.aarnio@tele.fi> For resource conscious mailer, look at the ZMailer: ftp://ftp.funet.fi/pub/unix/mail/zmailer/
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