Database error

I am getting database error few times a day for last few weeks and I can't find the problem. Forum stays down about hour and half and then it comes online unless I restart mysql before. Yesterday I upgrade vbseo to 3.6 but nothing changed, error still showing up.
It happening even in the early morning when traffic is 10%-15% of what I get in the evening.
When I look in whm, memory used go to 65%-70%, mysql is still up, but database error show if you try to open forum. Server has 12GB RAM and it is very strong.


Here are some lines :

Code:

Warning: mysqli_get_server_info() [function.mysqli-get-server-info]: invalid object or resource
mysqli in .../public_html/vbseo/includes/functions_vbseo_db.php
on line 145

Warning: reset() [function.reset]: Passed variable is not an array or object in
.../public_html/vbseo/includes/functions_vbseo_createurl.php on
line 528

Warning:  mysqli_get_server_info() [function.mysqli-get-server-info]: invalid object or resource mysqli  in .../public_html/vbseo/includes/functions_vbseo_db.php on line 148

Warning: Variable passed to each() is not an array or object in .../public_html/vbseo/includes/functions_vbseo_createurl.php on line 530

Warning: Cannot modify header information - headers already sent by (output started
at .../public_html/vbseo/includes/functions_vbseo_db.php:145) in
/home/serbian1/public_html/404.php on line 2

Warning: Cannot modify header information - headers already sent by (output started
at .../public_html/vbseo/includes/functions_vbseo_db.php:145) in
/home/serbian1/public_html/404.php on line 3

Thanks

What is the exact database error are you receiving ?

I don't understand what is exacts database error. When you try to open some of the pages you see standard message for it and above information.


http://i51.tinypic.com/1z4bmkh.gif

You need to view-source of that error page to get the full html comment of the DB error.

<!--
Database error in vBulletin :

mysqli_real_connect() [&lt;a href='function.mysqli-real-connect'&gt;function.mysqli-real-connect&lt;/a&gt;]: (08004/1040): Too many connections
/home/serbian1/public_html/includes/class_core.php on line 1317

MySQL Error :
Error Number :
Request Date : Thursday, October 20th 2011 @ 01:19:12 AM
Error Date : Thursday, October 20th 2011 @ 01:19:12 AM
Script : http://serbianforum.org/forumdisplay.php?f=0
Referrer :
IP Address : 188.2.113.12
Username :
Classname : vB_Database_MySQLi
MySQL Version :
-->

That error is directly related to your MySQL configuration. You need to increase MySQL max_connections value and restart MySQL

I already have max_conections set to 500. I change it now to 800 but I think this is to much for 30k visits per day.

It's possible your wait_timeout is set to high, there by tying up the connections for X time period. 180 is generally recommended

I don't even have wait_timeout in my.cnf. After setting max_conections to 800 I have new mysql error with max_user_connections which is set to 500.


Database error in vBulletin : mysqli_real_connect() [&lt;a href='function.mysqli-real-connect'&gt;function.mysqli-real-connect&lt;/a&gt;]: (42000/1203): User serbian1_zems already has more than 'max_user_connections' active connections /home/serbian1/public_html/includes/class_core.php on line 1317


Should I add wait_timeout=180 ?

Edit 1:
-------------------------------------

I looked in variables in phpmyadmin and I saw I have wait_timeout set to 28,800 but I still can't find it in my.cnf file.
Where should I look for it?

This is my my.cnf file:

query_cache_type=1
max_user_connections=500
max_connections=500
thread_cache_size=256
table_cache=16384
key_buffer=64M
max_connect_errors=20
max_allowed_packet=128M
join_buffer=2M
record_buffer=1M
sort_buffer_size=2M
read_buffer_size=2M
read_rnd_buffer_size=1M
thread_concurrency=16
myisam_sort_buffer_size=64M
local-infile=0
concurrent_insert=2



Edit2:
------------------------------------
OK, I added wait_timeout=180 and restarted mysql but they I got warning and fatal error:

Warning: require_once([path]/includes/adminfunctions_template.php) [function.require-once]: failed to open stream: Too many open files in system in [path]/includes/class_bootstrap.php(537) : eval()'d code on line 71

Fatal error: require_once() [function.require]: Failed opening required '/home/serbian1/public_html/includes/adminfunctions_template.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/serbian1/public_html/includes/class_bootstrap.php(537) : eval()'d code on line 71

my.cnf will only over-ride defaults. If it's not set, it will run oem/default configuration.

This is my file in my 8gb machine serving about 600 at once average.

Note, I do NOT use mysqli, and you may have better luck using the default mysql engine instead.

Code:

[mysqld]
back_log = 50
skip-innodb
max_connections = 1024
key_buffer_size = 32M
myisam_sort_buffer_size = 64M
join_buffer_size = 2M
read_buffer_size = 2M
sort_buffer_size =42M
table_cache = 1024
thread_cache_size = 384
wait_timeout = 190
connect_timeout = 10
tmp_table_size = 64M
max_heap_table_size = 64M
max_allowed_packet = 64M
net_buffer_length = 16384
max_connect_errors = 10
thread_concurrency = 16
concurrent_insert = 2
table_lock_wait_timeout = 30
read_rnd_buffer_size = 786432
bulk_insert_buffer_size = 8M
query_cache_limit = 4M
query_cache_size = 64M
query_cache_type = 1
query_prealloc_size = 262144
query_alloc_block_size = 65536
transaction_alloc_block_size = 8192
transaction_prealloc_size = 4096
default-storage-engine = MyISAM

[mysqldump]
quick
max_allowed_packet = 128M

[myisamchk]
key_buffer = 64M
sort_buffer = 64M
read_buffer = 16M
write_buffer = 16M

How can I change mysqli to mysql?
Should I do it in config.php file of vbulletin?

$config['Database']['dbtype'] = 'mysql';

Thanks for your help.

Actually i always suggest mysqli over mysql . Mysqli always serves faster for me.

Ok, I added wait timeout to 190, increase max_connections to 1024 and delete max_user_connections but I still getting database error for to many connections.
I don't know what to do any more to fix this.

You may want to check with your host to see if you are beeing DDoS'ed