[Fwd: Re: broken forwarder?]
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I thought this would intrest the "how does that work" folks on the list. Besides being a very good freind, and hosting both my site and e-mail, Tom is one of the people responsible for getting me to switch from MS to linux. I had come up with a hypothisis based on what info i had, and reported the broken forwarder. but I'd also asked if he was using sendmail or postfix, so I could learn more, so next time I could say " it is doing (this), therefore, i belive (this) is the problem. after all saying I can't get e-mail is about as useful as saying water is wet. ~ both are true, and both are useless statements. so anyhow, here's a look at how a sendmail server works. oh, and if perchance you do live in Helena, I highly reccomend using his ISP (tmcom.com) for your service. at the very least you'd know you were connected to a linux machine :-) u - -------- Original Message -------- Subject: Re: broken forwarder? Date: Thu, 8 May 2003 10:08:54 -0600 (MDT) From: Tom Mandera < Reply-To: To: nqs@dialup.tmcom.com References: <3EB3ED7A.7040206@tmcom.com> | -----BEGIN PGP SIGNED MESSAGE----- | Hash: SHA1 | | Tom, | | I didn't recive any mail this morning, which is un usual, as the Suse | list is very active, although of course not unheard of. I tried first | sending myself a test message, but didn't see it. however a message to | tigger.tmcom.com did show up. so it looks to me like the forwardetr is | broken. I'm running Sendmail on all of my machines. Here's the scoop. The Sendmail daemon on "tmcom.com" died over the weekend. Lots of mail backed up on "tigger" waiting for delivery to "email.tmcom.com" (aka tmcom.com). I became aware of the problem late on Sunday (spent Saturday putting in Guardrail at the rally site) and fixed it. So then the mail queued up on Tigger started heading to "email" for processing. A lot of it was SPAM, and "email" rejected it, and then "tigger" started trying to send the messages back to the sender.. being spam, most of the "from" addresses were fictitious. The result, was the mail to "tmcom.com" went in, but there were SEVENTY THOUSAND messages backed up on "tigger" to get sent back to the sender.. which kept failing. So your email first got queued on "tigger" for delivery to "nqs@tmcom.com".. then I got "tmcom.com" up, so your mail went there.. and got forwarded to "nqs@tigger.tmcom.com".. BUT.. since "tigger" was busy trying to send out all of this junk, the server utilization spiked.. and I had more than 12 processes running at once (more like 25-30).. after 12 processes, Sendmail stops accepting incoming email.. so "tigger" sent your mail to "tmcom.com", but wouldn't accept incoming mail BACK from "tmcom.com".. I spent a lot of time this week trying to get the mail spool cleaned out of "bogus" spam messages and get the #s down to a manageable level.. among other things, you can't even do an "ls *5*" on 70,000 messages because the result is 50,000 messages, and LS won't take that many parameters.. after about 4,000 files it starts to die, so any scripts I found to clear out "bounced" mail puked.. I ended up moving files off into sub-dirs and processing them as well as I could and then merging things back.. before I finally remembered a program called "xargs" that let me start churning through all 70,000 files.. which cut it down to 40-50k This morning, I'm down to 16k. Somewhere along the line, I also managed to screw up the permissions on "tigger" such that even when the server utilization wasn't high, it couldn't take in new mail.. I fixed that yesterday afternoon. As of this morning, things are looking better and processing "normally".. and I've been re-investigating additional spam-blocking measures. I'm already using a few black-lists and rejecting a ton of mail (which, in this case, almost hurt me more than helped).. Other good news - I have cable at my new house now, so I can keep my finger on things better again. It was hard to do with just dialup.. and this week's been a busy one for me, getting home at 10pm most nights anyhow.. That help explain it? I did see a bunch of mail going through for you yesterday afternoon/evening.. - -Tom -- SuSE Linux 8.1 (i386) Kernal: 2.4.19-4GB i686 Posted from: Miverna ~ 9:40am up 2 days, 12:16, 4 users, load average: 0.12, 0.17, 0.28 The abortion rights and gun control debates are twin aspects of a deeper question --- does an individual ever have the right to make decisions that are literally life-or-death? And if not the individual, who does? - -- Eric S. Raymond nqs@tmcom.com | Blog: http://tigger.tmcom.com/~nqs/blogger.html GPG key can be found at: http://pgpkeys.mit.edu:11371/ | Geek Code: http://tigger.tmcom.com/~nqs/geek_code.html
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Joe Dufresne