MySQL Bugs: #8945: unauthenticated user and server crash

Bug #8945	unauthenticated user and server crash
Submitted:	4 Mar 2005 12:53	Modified:	9 Apr 2005 12:38
Reporter:	Marek Wylon	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	MySQL Server: MyISAM storage engine	Severity:	S1 (Critical)
Version:	4.1.7	OS:	Linux (Linux Enterprise)
Assigned to:		CPU Architecture:	Any

Description:
Each day exactly at 12:05 my sql server hangs up for 5-10 minutes or crashes.
At process list I have something like this:

| 3436942 | unauthenticated user | 192.168.0.52:49607 |                | Connect     |        | login                                                          |                       |
| 3436943 | unauthenticated user | 192.168.0.52:49608 |                | Connect     |        | login                                                          |                       |
| 3436944 | unauthenticated user | 192.168.0.52:49609 |                | Connect     |        | login                                                          |                       |
| 3436945 | unauthenticated user | 192.168.0.52:49610 |                | Connect     |        | login                                                          |                       |
| 3436946 | unauthenticated user | 192.168.0.52:49611 |                | Connect     |        | login                                                          |                       |
| 3436947 | unauthenticated user | 192.168.0.52:49612 |                | Connect     |        | login                                                          |                       |
| 3436948 | unauthenticated user | 192.168.0.2:41049  |                | Connect     |        | login                                                          |                       |
| 3436949 | unauthenticated user | 192.168.0.52:49613 |                | Connect     |        | login                                                          |                       |
| 3436950 | unauthenticated user | 192.168.0.52:49614 |                | Connect     |        | login                                                          |                       |
| 3436951 | unauthenticated user | 192.168.0.52:49615 |                | Connect     |        | login                                                          |                       |
| 3436952 | unauthenticated user | 192.168.0.52:49616 |                | Connect     |        | login                                                          |                       |

Sometimes there is 300 such processes,
sometimes there is 800 or 1000.

Server load doesn't increase, processor load, memory useage is the same during problem. sometimes server need 10 minutes to come back and to work normally, sometimes many hours.

I have log files with:
- top results reported each 5 minutes
- processlist from mysqladmin reported each 5 minutes,
- all sql query log,
- all sql query in binlog format,
- all details about machine load in rrd format,

If it can be helfull I can email it.

machine replacates data to other machine - replication server works fine and don't generate any problems.

At the evening, when there is 2-3 x more queries to server problem never appears. It is something connected with hour 5:00AM. I restarted server many times at many hours and problem always return at the same time.
I checked queries that come to server - nothing special come at 5:00.

Mark

How to repeat:
Don't know. I observe it at my machine each day at 5:05.

Hi!

Do you have any cron-tasks at 12:05?

I had a similar situation on my setup where the database lived on a different host than the webserver.  I found the "unauthenticated users" were connections from the webserver that were hanging on DNS lookups.  Don't know if this is a mysql bug or a bug with my firewall / other setup, but a couple of fixes I found were...

1) start mysql with --skip-name-resolve (you may have to change your mysql permission tables to have the host's IP instead of hostname, including localhost)

or 2) add the connecting host to your /etc/hosts file.

Hope that helps.

I am also experiencing this "unauthenticated user" business. Just noticed it today. And yes, the IP address in the process list is our webserver.

And yes, we have several cron jobs that connect to it.

All of the entries in 'show processlist' are showing IP addresses so I don't understand the problem. And we don't use hostnames in any of the mysql tables either.

I'm using 4.1.10 on RH9

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

Hello;

who can help you. i have a problme.

| 10116 | unauthenticated user | 66.90.xxx:48359 |                   | Connect |      | Reading from net |                                                                                                      |
| 10117 | unauthenticated user | 66.90.xxx:48360 |                   | Connect |      | Reading from net |                                                                                                      |
| 10118 | unauthenticated user | 66.90.xxx:48361 |                   | Connect |      | Reading from net |  

i have every time this problem. how can i fix this problem ? 

please write with command. because i am beginner.

Thx

Akif

ok took me awhile to figure out as everytime I had this problem it was caused to not having skip-name-resolve

so if you have this problem and you have skip-name-resolv in your my.cnf, make sure you have it in the [mysqld] section if you use mysql as a daemon.

stupid and obvious you will say but little mistakes causes headaches and thought this might help as skip-name-resolv did fix this on over 30 servers I've encountered over my "career".