Thanks - I'll give these a try should it happen again.
Jeff
On 9/17/2017 3:10 PM, Eric Broch wrote:
And, here's another one:
mysql -u root -ppassword -BNe "select host,count(host) from
processlist group by host;" information_schema
Explanation:
Display the number of connections to a MySQL Database
Count the number of active connections to a MySQL database.
The MySQL command "show processlist" gives a list of all the active
clients.
However, by using the processlist table, in the information_schema
database, we can sort and count the results within MySQL.
On 9/17/2017 11:33 AM, Jeff Koch wrote:
Eric - thanks ! Jeff
On 9/17/2017 11:14 AM, Eric Broch wrote:
Hi Jeff,
Here are some commands you can run to determine the number of
connections (to determine if this is the issue) to the MariaDB in
the event that this happens again:
1) echo "show full processlist" | mysql -u root -ppassword
2) doveadm who
3) ps aux | grep vpopmail | grep dovecot
Eric
On 9/15/2017 4:02 PM, Jeff Koch wrote:
I raised it to 300 but we're a little concerned about all these
root sessions. Could they be a form of break-in attempt and why
would they affect mysql to the point that dovecot could not
connect. And what the heck is a 'user-89.slice. vpopmail is usually
user 89.
Jeff
On 9/15/2017 5:57 PM, Eric Broch wrote:
I think I'd try upping the connection count, what's it at 151?
On 9/15/2017 3:25 PM, Jeff Koch wrote:
Nope.
But I did see this strange series of entries in /var/log/messages
- which started at 12:03 and continued to 12:15. This was the
same period that dovecot was complaining that it couldn't connect
to mysql
Sep 15 12:04:01 vid systemd: Started Session 208671 of user root.
Sep 15 12:04:01 vid systemd: Starting Session 208671 of user root.
Sep 15 12:04:01 vid systemd: Started Session 208670 of user root.
Sep 15 12:04:01 vid systemd: Starting Session 208670 of user root.
Sep 15 12:04:01 vid systemd: Started Session 208672 of user root.
Sep 15 12:04:01 vid systemd: Starting Session 208672 of user root.
......
..........
Sep 15 12:15:01 vid systemd: Starting Session 208707 of user root.
Sep 15 12:15:01 vid systemd: Started Session 208709 of user root.
Sep 15 12:15:01 vid systemd: Starting Session 208709 of user root.
Sep 15 12:15:01 vid systemd: Started Session 208708 of user root.
Sep 15 12:15:01 vid systemd: Starting Session 208708 of user root.
Sep 15 12:15:01 vid systemd: Created slice user-89.slice.
Sep 15 12:15:01 vid systemd: Starting user-89.slice.
Sep 15 12:15:01 vid systemd: Started Session 208710 of user vpopmail.
Sep 15 12:15:01 vid systemd: Starting Session 208710 of user
vpopmail.
Sep 15 12:15:17 vid clamd: SelfCheck: Database status OK.
Sep 15 12:15:18 vid systemd: Removed slice user-89.slice.
Sep 15 12:15:18 vid systemd: Stopping user-89.slice.
Jeff
On 9/15/2017 4:09 PM, Eric Broch wrote:
Any entries in /var/log/mariadb/mariadb.log ?
On 9/15/2017 1:21 PM, Jeff Koch wrote:
For about a 15 minutes period users couldn't receive emails -
emails were bouncing back saying the users did not exist. We
traced the problem to the dovecot log where we saw this:
Sep 15 12:16:23 auth-worker: Error: vmysql: sql error[3]: Table
'vpopmail.users' doesn't exist
Sep 15 12:16:23 auth-worker: Error: Attempting to rebuild
connection to SQL server
Sep 15 12:16:23 auth-worker: Error: vmysql: connection rebuild
failed: Table 'vpopmail.users' doesn't exist
Shortly thereafter dovecot was able to connect and emails began
being received normally again.
Any thoughts on how to prevent this in the future? Should we
raise the number of mysql connections - we're using the default.
Regards, Jeff Koch
--
Eric Broch
White Horse Technical Consulting (WHTC)
--
Eric Broch
White Horse Technical Consulting (WHTC)
--
Eric Broch
White Horse Technical Consulting (WHTC)
