Greg Swift wrote: > Dallas L. Engelken wrote: >>> -----Original Message----- >>> From: ISP Lists [mailto:[EMAIL PROTECTED] >>> Sent: Wednesday, August 24, 2005 10:21 AM >>> To: vchkpw@inter7.com >>> Subject: Re: [vchkpw] Spotty behavior authenticating: MySQL server >>> has gone away >>> >>> >>>> Something peculiar happened to mysql during a reboot and >>>> >>> now vpopmail >>> >>>> authdaemond is having trouble completing authentications.... >>>> >>>> /var/log/maillog says: >>>> >>>> Aug 24 08:36:15 hostname authdaemond: vmysql: sql error[3]: MySQL >>>> server has gone away >>>> >>>> >>>> This problem is spotty though. I have several successful >>>> authentications before this error occurs. I then have to restart >>>> mysqld before I can get any other authentications to succeed. I am >>>> still able to use the mysql client to connect to the server >>>> >>> for an interactive session. >>> >>>> What seems strange to me is that there are only two mysql >>>> >>> daemons running: >>> >>>> root 23923 0.0 0.1 5060 1108 pts/0 S 09:13 >>>> >>> 0:00 /bin/sh >>> >>>> /usr/bin/safe_mysqld --defaults-file=/etc/my.cnf >>>> --pid-file=/var/run/mysqld/mysqld.pid >>>> >>>> mysql 23956 0.0 0.5 38620 5656 pts/0 Sl 09:13 0:00 >>>> /usr/libexec/mysqld --defaults-file=/etc/my.cnf --basedir=/var/lib >>>> --datadir=/var/lib/mysql --user=mysql >>>> --pid-file=/var/run/mysqld/mysqld.pid --skip-locking >>>> >>>> >>>> Every other instance of mysql 3.23.x I've ever run has >>>> >>> about 10 child >>> >>>> threads running, so this seems strange to see only one child >>>> thread. >>>> >>>> I have not updated any packages on this box recently. None >>>> >>> at all, I >>> >>>> swear. >>>> >>>> Suggestions to investigate? Googling on the "MySQL server >>>> >>> has gone away" >>> >>>> is a wild goose chase. >>>> >>>> >>>> >>>> >>>> >>>> >>> Hrm, rebooting the box seems to have helped. Still same >>> number of mysql daemons, but they're answering now... Damned >>> strange. dmesg on reboot didn't show any ext3 errors being >>> fixed - I was wondering if this was a disk thing. >>> >>> Thoughts still welcome and appreciated on this. >>> > Well.. just for reference (cause it took me a while to figure this one > out)... if your box is running with multiple name servers configured > for resolution, and the primary stops responding, you will see this > same issue. What happens is the slight delay added to the auth > sequence as the mysql fails to the secondary resolver causes the > vpopmail to fail the connection. > > > To be more specific this will occur: > > 1: primary name server fails > 2: When authentication to DB it takes a longer time due to system > having to fail to secondary resolver. > 3: vpopmail's auth to db starts failing due to timeouts (mysql takes > to long to respond, but does respond), vpopmail tries harder to > connect to db, connection count sky rockets (I saw upwards of 1400 > connections) and in turn the connections do not close properly. > 4: db locks up hard. > 5: once you quiet down vpopmail (easiest way was to disable incoming > access sadly), test messages show that an occasional message wil lgo > through, but the rest receive the "MySQL server has gone away" > message. > 6. Trying to auth to db, albeit slightly slower than normal, responds > and allows auth. Once in runs perfectly. > 7. You realize that its primary dns server is off for whatever reason, > start it, and voila no problem. > > > Now admittedly, previously I've seen the same thing but for other > reasons, this was just the more obscure annoying one. > > Yes I realize that a local dns server make a lot of sense for this > situation, but if the named on that box stops, and it has your other > name servers as secondary, WHEN are you gonna realize that? Most > people would not add that to their monitoring. LOTS of fun. > > -Greg
Or, I would think, you could just add the server/client to the hosts file(s) and skip DNS entirely. Or use IP addresses.
