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From:Brent Baisley Date:August 29 2005 5:45pm
Subject:Re: mySQL Performance Problems - Help !!
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If you suddenly are spiking in unauthenticated connections, you may  
be the target of a network attack. This could be just a random probe,  
you may be a random target or someone may be targeting you. Although  
if someone were specifically targeting you, you would probably be down.

I would check where the connections are coming from, especially if  
this amount of traffic is not typical. Perhaps you can set a filter  
on your router to limit the number of connections from that IP range  
or deny that range altogether. Normally you don't allow direct access  
to MySQL from the outside, access is usually done through SendMail/ 
Postifx or Apache (PHP, Perl, etc), but your requirements may be  
different.

On Aug 29, 2005, at 4:58 AM, Callum McGillivray wrote:

> Hi all,
>
> I'm pretty new to the list, so please be kind :)
>
> I'm having serious problems with our core mysql server.
>
> We are running a Dell Poweredge 2850 with dual Xeon 3.0 processors,  
> RAID 5 and 1Gb memory.
>
> There are 3 main databases running on this machine, one is a  
> freeradius database, one is for vpopmail and the other is for cacti  
> (MRTG based tool).
>
> At the moment, we find the suddenly, our mail server or cacti  
> server will establish several hundred connections to the database  
> that just seem to be sit in an "unauthenticated" state.
>
> E.G.
> | 6452 | unauthenticated user | xxx.xxx.xxx.xxx:40923     |  
> NULL         | Connect | NULL | login | NULL             |
> | 6453 | unauthenticated user | xxx.xxx.xxx.xxx:40924     |  
> NULL         | Connect | NULL | login | NULL             |
>
> The server starts dragging it's heals and mail and cacti virtually  
> stop altogether.  There does not seem to be any unusual CPU / I/O  
> or memory usage when this happens.
>
> Can anyone point me in the right direction here ?
>
> I'm more than happy to provide any configuration information that  
> is required - but this is killing us and I need to know what is  
> going on.
>
> We have run this server for several years (recently we upgraded the  
> hardware without problems) and we have never experienced anything  
> like this.
>
> I am at my wits end and not having had any formal training in mySQL  
> servers, I simply don't know what I should be looking at next.
>
> Please - if anyone can give me any insight at all on this it would  
> be MOST appreciated.
>
> Warm regards,
>
> Callum
>
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>

-- 
Brent Baisley
Systems Architect
Landover Associates, Inc.
Search & Advisory Services for Advanced Technology Environments
p: 212.759.6400/800.759.0577


Thread
mySQL Performance Problems - Help !!Callum McGillivray29 Aug
  • Re: mySQL Performance Problems - Help !!Xiaodong Deng29 Aug
  • Re: mySQL Performance Problems - Help !!Brent Baisley29 Aug