[CentOS] MySQL ERROR - UNKNOWN_MYSQL_USER

Wed Jul 20 21:41:09 UTC 2011
Ljubomir Ljubojevic <office at plnet.rs>

Keith Roberts wrote:
> On Wed, 20 Jul 2011, Ljubomir Ljubojevic wrote:
> 
>> To: CentOS mailing list <centos at centos.org>
>> From: Ljubomir Ljubojevic <office at plnet.rs>
>> Subject: Re: [CentOS] MySQL ERROR - UNKNOWN_MYSQL_USER
>>
>> Keith Roberts wrote:
>>> This is strange behavior because as soon as I start mysqld
>>> with a clean error log, I get the following messages:
>>>
>>> 110720 21:38:47 [Note] /usr/libexec/mysqld: ready for
>>> connections.
>>> Version: '5.5.14-log'  socket: '/var/lib/mysql/mysql.sock'
>>> port: 2500  MySQL Community Server (GPL) by Remi
>>>
>>> 110720 21:38:48 [Warning] Access denied for user
>>> 'UNKNOWN_MYSQL_USER'@'localhost' (using password: NO)
>>>
>>> The strange things is, AFAIK there are no clients trying to
>>> connect to mysql. I shutdown a mysql CLI monitor I had
>>> running, and did the restart again.
>>>
>>> So I'm just wondering why I get this message, when AFAIK
>>> there is nothing that should be trying to connect to mysql -
>>> unless it's a server daemon running somewhere?
>>>
>>> Has anyone else come across this funny error message?
>>>
>> There must be some service that does uses MySQL but does 
>> not have user set. Website like CMS? Try getting more logs 
>> to see what app/script uses it.
> 
> Hi Ljubomir.
> 
> It might be collectd that can use mysql. The man page is 
> over 5,000 pages for the config file. I seem to remember 
> seeing a message at boot time about collectd not being 
> configured properly to use mysql.
> 
> I installed collectd recently, so I could monitor my HDD 
> temperatures using GKrellM, which it's doing OK.

Then all you need to do is "service collectd stop; service mysqld start" 
and check the logs.

-- 

Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

Google is the Mother, Google is the Father, and traceroute is your
trusty Spiderman...
StarOS, Mikrotik and CentOS/RHEL/Linux consultant