Just following up on my own question a bit... I'm trying to figure out how many mysql hits a single incoming message can generate to arrive at a max_connections setting for mysql.
Worst case, I assume it would look like this: -initial chkusr check (is it a valid address?) -smtp-auth (possible if it's a local user sending to another) -vdelivermail (look up where to deliver) -spamc (if user has spamassassin enabled, prefs fetched via mysql) Am I missing anything on the delivery side? These obviously aren't all concurrent, but the hits are all pretty rapid-fire. So if I am allowing a max of 100 concurrent qmail-smtpd's, what would be a "safe" number of concurrent mysql connections when the box is maxed out? Multiply 100 by 2, 3, 4? For mail retrieval, I can measure a bit more easily... Thanks, Charles On Tue, 11 May 2004, Charles Sprickman wrote: > Howdy, > > I've seen a few people complaining that their mail is getting bounced. > Not good, needless to say. On examing the bounces, I see that it's the > chkusr error message that the user does not exist. > > At this point my best guess, by looking at overall server activity is that > this is happening when the machine really gets swamped (all incoming smtp > connections chewed up with spam runs - this server and a backup server). > I have mysql set to 500 max connections, and just bumped that up to 800. > > I was surprised a bit by how chkusr behaves if the mysql server goes away > - rather than erring on the side of caution and trying to deliver the > mail, it bounces it. I verified this on a test box. > > FWIW, this is the Shupp chkusr patch, there's no version info in the > patch, but it looks like it was made 3/16/2003. > > Is this how chkusr is "supposed" to operate? If so, I need an > alternative, as most other parts of vpopmail survive a brief database > outage without dumping good mail. > > Are there any other tested "chkusr" type patches out there? Please share! > > Thanks, > > Charles >
