Hi
From a thread found on the net it also suggests that it might be network
or DNS related.
The connections building up is the following:
*************************** 1346. row
***************************
Id: 903175
User: unauthenticated user
Host: <ip>:51798
db: NULL
Command: Connect
Time: NULL
State: login
Info: NULL
The servers however only uses ip connections and no DNS
related lookups.
From what I could find on the web though it seems that there
is one session that is unable to authenticate and the authentication process
does not complete causing it to get "stuck"
This then causes all other requests to wait for the
transaction to complete.
Everyone who replied to these threads with the same issue
stated that when they kill that one problem connection it brings everything
back to normal again, however the problem happens regularly and if not
picked up immediately eventually causes an inability to access the database
to even kill processes, etc...
So what I know now is that the problem is caused by a
connection / transaction not completing. However what I need to find out now
is why and how to resolve this.
Machiel Richards
MySQL DBA
Relational Database Consulting
RDC_Logo
From: Rob Wultsch [mailto:wult...@gmail.com]
Sent: 02 July 2010 9:42 AM
To: Machiel Richards
Cc: mysql@lists.mysql.com
Subject: Re: Mysql connections not released
On Thu, Jul 1, 2010 at 11:58 PM, Machiel Richards <machi...@rdc.co.za>
wrote:
Good morning all
A few days ago i posted some questions relating to mysql
threads running out and not being able to restart the database.
We had the same again this morning however this time I had a
bit of a heads up and managed to get into the database before it went down
(so to speak).
What I found was the following:
. When running ' show processlist', the amount of processes were
increasing the whole time.
. From the details, it seemed that all the connections were coming
from the website and were trying to make connections to the database,
however the statuses never changed from connect to anything else, and yet
the amount of connections kept on rising.
. From what I could gather, the incoming processes were trying to
connect to the database but the connections could not be released causing
havoc.
I have tried to find clues in log files, etc... but nothing turned up. I
suspected that it could perhaps be php however this could not be verified
yet.
Can someone please provide me with some thoughts as to why this could be
happening? I am fairly new to MySQL and not sure where else to go from here
to find the root cause.
Generally everything works fine, however , every now and then things
suddenly seem to be going wrong... L
Any help would be appreciated.
Machiel Richards
MySQL DBA
Relational Database Consulting
Error! Filename not specified.
My first guess would be a networking problem. If you run ifconfig repeatedly
do you notice the number of errors increasing? It would be good to look at
both the database server and the web server. Also, until you figure the
issue out you should be able to mitigate it by setting the connect timeout
to a more aggressive value.
--
Rob Wultsch
wult...@gmail.com
