mysql lost without dead. strange!

[lukeot]

Hi
sorry for my english.

I've a server with 2xquad core 2.55 with 7Gb RAM + 8 Swap
and External Storage

from 1 months i work on mysql to optimize.
I read a lot, i change a lot, i used tuning-primer and mysqltuner.pl too. NO FIX
MySql work only in localhost (i ping localhost and don't loose packets)
My .my.cnf i think is good (tuning and mysqltuner answer= all perfect)
I Change a lot of time wait_timeout= (from 10 to 100)
I add variable, i delete variable
Load is perfect = 0.1% (only when there is upcpc and backup go up = 1.10%)
IDLE is perfect (98% - 99%)
Mytop is perfect. No persistent connection, nothing....BUT I'VE A BIG PROBLEM!

sometimes i receive (me and others customer) "lost connection mysql", "lost connection 2006"

example: i open a site, a click a link (php + query mysql) and in less 1 second i receive that error.
I refresh and all is OK

MyTop too lost connection without error
example:
i open Mytop, after 5,7, 8, 3, 10 minutes something kill Mytop
Immediatly i re-open Mytop and all is OK

Into mysql-error files, i've no informations.


This is a big problem. right?


PLEASE can you help me?



my.cnf (last my.cnf. . I change it a lot of time)

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-locking
skip-networking
safe-show-database
query_cache_limit=4M
query_cache_size=224M
query_cache_type=1
max_user_connections=50
max_connections=300
interactive_timeout=20
wait_timeout=40
connect_timeout=20
thread_cache_size=128
key_buffer=512M
join_buffer_size=2M
max_connect_errors=9999
max_allowed_packet=32M
table_cache=4096
tmp_table_size=256M
max_heap_table_size=256M
record_buffer=2M
key_buffer_size=256M
sort_buffer_size=6M
read_buffer_size=6M
read_rnd_buffer_size=4M
thread_concurrency=8
#myisam_sort_buffer_size=64M
server-id=1
log-slow-queries=/var/log/mysql-slow-queries.log
long_query_time=3
collation-server=latin1_general_ci

#[mysql.server]
#user=mysql
#basedir=/var/lib

[safe_mysqld]
err-log=/var/log/mysqld.log
pid-file=/var/lib/mysql/mysql.pid
open_files_limit=8192

[mysqldump]
quick
max_allowed_packet=32M

[mysql]
no-auto-rehash
#safe-updates

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


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

[mysqlhotcopy]
interactive-timeout=120

---
total used free shared buffers cached
Mem: 7862100 7754560 107540 0 543656 5791728
-/+ buffers/cache: 1419176 6442924
Swap: 8385920 65196 8320724

----

Thanks a lot

[lukeot]

Hi
sorry for my english.

I've a server with 2xquad core 2.55 with 7Gb RAM + 8 Swap
and External Storage

from 1 months i work on mysql to optimize.
I read a lot, i change a lot, i used tuning-primer and mysqltuner.pl too. NO FIX
MySql work only in localhost (i ping localhost and don't loose packets)
My .my.cnf i think is good (tuning and mysqltuner answer= all perfect)
I Change a lot of time wait_timeout= (from 10 to 100)
I add variable, i delete variable
Load is perfect = 0.1% (only when there is upcpc and backup go up = 1.10%)
IDLE is perfect (98% - 99%)
Mytop is perfect. No persistent connection, nothing....BUT I'VE A BIG PROBLEM!

sometimes i receive (me and others customer) "lost connection mysql", "lost connection 2006"
Into var/log/mysqld.log i don't find error, only my restarts

example: i open a site, a click a link (php + query mysql) and in less 1 second i receive that error.
I refresh and all is OK

MyTop too lost connection without error
example:
i open Mytop, after 5,7, 8, 10 minutes something kill Mytop
Immediatly i re-open Mytop and all is OK

Into mysql-error files, i've no informations.


This is a big problem. right?


PLEASE can you help me?



PHP.ini= memory changed in 64Mb

my.cnf (last my.cnf. . I change it a lot of time)

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-locking
skip-networking
safe-show-database
query_cache_limit=4M
query_cache_size=224M
query_cache_type=1
max_user_connections=50
max_connections=300
interactive_timeout=20
wait_timeout=40
connect_timeout=20
thread_cache_size=128
key_buffer=512M
join_buffer_size=2M
max_connect_errors=9999
max_allowed_packet=32M
table_cache=4096
tmp_table_size=256M
max_heap_table_size=256M
record_buffer=2M
key_buffer_size=256M
sort_buffer_size=6M
read_buffer_size=6M
read_rnd_buffer_size=4M
thread_concurrency=8
#myisam_sort_buffer_size=64M
server-id=1
log-slow-queries=/var/log/mysql-slow-queries.log
long_query_time=3
collation-server=latin1_general_ci

#[mysql.server]
#user=mysql
#basedir=/var/lib

[safe_mysqld]
err-log=/var/log/mysqld.log
pid-file=/var/lib/mysql/mysql.pid
open_files_limit=8192

[mysqldump]
quick
max_allowed_packet=32M

[mysql]
no-auto-rehash
#safe-updates

[isamchk]
key_buffer=64M (i changed 256 but no fix)
sort_buffer=64M (i changed 256 but no fix)
read_buffer=16M
write_buffer=16M


[myisamchk]
key_buffer=64M (i changed 256 but no fix)
sort_buffer=64M (i changed 256 but no fix)
read_buffer=16M
write_buffer=16M

[mysqlhotcopy]
interactive-timeout=120


---
total used free shared buffers cached
Mem: 7862100 7754560 107540 0 543656 5791728
-/+ buffers/cache: 1419176 6442924
Swap: 8385920 65196 8320724




THANKS