Hello,

My server receives about 10K visits per day. My load average is very
high and the web page access is very slow. Here is what the top
command is showing at this moment:

top - 18:26:35 up 39 days, 1:47, 1 user, load average: 27.78,
20.28, 16.71
Tasks: 260 total, 40 running, 220 sleeping, 0 stopped, 0 zombie
Cpu(s): 89.6% user, 10.4% system, 0.0% nice, 0.0% idle
Mem: 2059776k total, 2010388k used, 49388k free, 7328k
buffers
Swap: 522104k total, 4000k used, 518104k free, 596032k
cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2906 mysql 20 0 165m 165m 4236 R 25 8.2 0:01.13 mysqld
22769 mysql 18 0 165m 165m 4236 R 7 8.2 0:00.32 mysqld
17734 mysql 20 0 165m 165m 4236 R 7 8.2 0:00.39 mysqld
4572 mysql 20 0 165m 165m 4236 R 7 8.2 0:00.41 mysqld
3220 mysql 18 0 165m 165m 4236 R 7 8.2 0:00.30 mysqld
27183 mysql 20 0 165m 165m 4236 R 6 8.2 0:04.46 mysqld
15198 mysql 20 0 165m 165m 4236 R 6 8.2 0:00.60 mysqld
11356 mysql 17 0 165m 165m 4236 R 6 8.2 0:00.29 mysqld
25333 mysql 16 0 165m 165m 4236 R 6 8.2 0:00.29 mysqld
25410 mysql 20 0 165m 165m 4236 R 6 8.2 0:02.14 mysqld
5483 mysql 19 0 165m 165m 4236 R 6 8.2 0:01.38 mysqld
22889 mysql 17 0 165m 165m 4236 R 6 8.2 0:01.20 mysqld
32038 mysql 16 0 165m 165m 4236 R 6 8.2 0:00.27 mysqld
6988 mysql 18 0 165m 165m 4236 R 6 8.2 0:00.57 mysqld
4466 mysql 16 0 165m 165m 4236 R 6 8.2 0:00.52 mysqld
29683 mysql 16 0 165m 165m 4236 R 6 8.2 0:00.26 mysqld
26376 mysql 15 0 165m 165m 4236 R 6 8.2 0:00.35 mysqld
13625 mysql 16 0 165m 165m 4236 R 6 8.2 0:02.41 mysqld
3719 mysql 20 0 165m 165m 4236 R 6 8.2 0:02.18 mysqld
6659 mysql 20 0 165m 165m 4236 R 6 8.2 0:01.78 mysqld
4470 mysql 15 0 165m 165m 4236 R 6 8.2 0:01.12 mysqld
15762 mysql 20 0 165m 165m 4236 R 5 8.2 0:01.40 mysqld
111 mysql 20 0 165m 165m 4236 R 5 8.2 0:01.30 mysqld
23592 mysql 20 0 165m 165m 4236 R 5 8.2 0:01.29 mysqld
30569 mysql 20 0 165m 165m 4236 R 5 8.2 0:01.21 mysqld
25273 mysql 18 0 165m 165m 4236 R 5 8.2 0:00.58 mysqld
13 mysql 17 0 165m 165m 4236 R 5 8.2 0:00.38 mysqld
25768 mysql 18 0 165m 165m 4236 R 5 8.2 0:00.80 mysqld
32259 mysql 16 0 165m 165m 4236 R 5 8.2 0:00.51 mysqld
4812 mysql 16 0 165m 165m 4236 R 5 8.2 0:06.04 mysqld
17753 mysql 16 0 165m 165m 4236 R 5 8.2 0:05.33 mysqld
19635 mysql 16 0 165m 165m 4236 R 5 8.2 0:00.35 mysqld
5091 mysql 17 0 165m 165m 4236 R 5 8.2 0:03.77 mysqld
7554 mysql 16 0 165m 165m 4236 R 5 8.2 0:00.21 mysqld
2825 root 15 0 1208 1208 832 R 4 0.1 0:16.27 top
28608 nobody 10 0 15388 15m 8744 S 3 0.7 0:03.36 httpd
4920 nobody 10 0 15248 14m 8784 S 3 0.7 0:03.24 httpd
13035 nobody 9 0 15252 14m 8792 S 2 0.7 0:04.68 httpd
2021 nobody 10 0 15532 15m 8752 S 2 0.8 0:04.40 httpd
750 nobody 9 0 15444 15m 8792 S 2 0.7 0:02.71 httpd
31936 nobody 13 0 15328 14m 8780 S 2 0.7 0:05.01 httpd
32056 nobody 10 0 15308 14m 8780 S 2 0.7 0:01.79 httpd
25585 nobody 9 0 15472 15m 8780 S 1 0.8 0:03.46 httpd
7028 nobody 10 0 15140 14m 8696 S 0 0.7 0:01.49 httpd
26088 nobody 9 0 15160 14m 8736 S 0 0.7 0:01.23 httpd

Any idea what may cause this high load average and why http access is
so slow?

Thanks,

Antoni

Antoni wrote:
> Hello,
>
> My server receives about 10K visits per day.
> top - 18:26:35 up 39 days, 1:47, 1 user, load average: 27.78,
> 20.28, 16.71
> Tasks: 260 total, 40 running, 220 sleeping, 0 stopped, 0 zombie
> Cpu(s): 89.6% user, 10.4% system, 0.0% nice, 0.0% idle
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> 2906 mysql 20 0 165m 165m 4236 R 25 8.2 0:01.13 mysqld
> 22769 mysql 18 0 165m 165m 4236 R 7 8.2 0:00.32 mysqld
> Any idea what may cause this high load average and why http access is
> so slow?

I would think the SQL queries may be the cause to the high load, badly
designed queries and/or tables can cause the mysql to work hard, as you have a
high visitor numbers you will just multiply the trouble.

Without any more information it's difficult to know if there would be other
reasons too.

--

//Aho

Hello,

I tested all SQL queries and almost all respond in less than 0.02
seconds. It seems as if mysql connections live longer than what its
needed.

What more info do you need to figure out what might be the problem?

Thanks!

J.O. Aho ha escrit:
> Antoni wrote:
> > Hello,
> >
> > My server receives about 10K visits per day.
> > top - 18:26:35 up 39 days, 1:47, 1 user, load average: 27.78,
> > 20.28, 16.71
> > Tasks: 260 total, 40 running, 220 sleeping, 0 stopped, 0 zombie
> > Cpu(s): 89.6% user, 10.4% system, 0.0% nice, 0.0% idle
> > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
> > 2906 mysql 20 0 165m 165m 4236 R 25 8.2 0:01.13 mysqld
> > 22769 mysql 18 0 165m 165m 4236 R 7 8.2 0:00.32 mysqld
> > Any idea what may cause this high load average and why http access is
> > so slow?
>
> I would think the SQL queries may be the cause to the high load, badly
> designed queries and/or tables can cause the mysql to work hard, as you have a
> high visitor numbers you will just multiply the trouble.
>
> Without any more information it's difficult to know if there would be other
> reasons too.
>
> --
>
> //Aho

Antoni wrote:

> I tested all SQL queries and almost all respond in less than 0.02
> seconds. It seems as if mysql connections live longer than what its
> needed.

One time running may be ok, but if you do something 1000 times, can you then
recreate the load? Do you use a lot of joins?


> What more info do you need to figure out what might be the problem?

If you written it yourself, what language used, if you use someone else
software and what version. Version of webserver, mysql and php if you use
that. Architecture of the CPU could be good to know too (mc68k would be normal
with that load while an amd64/3000+ wouldn't).

If you are using PHP, switch from mysql_pconnect() to mysql_connect() and see
if you get it to become a bit smother.

--

//Aho

Hello,

I'm also using Wordpress, but it does not use that much joins either.

I'm using:

PHP 5
MySQL 5.0.21-log
Apache 2.0.59

Server Specs:

Linux 2.4.33grs-bipiv-ipv4-32 #1 i686 Intel(R) Core(TM)2 CPU T5500 @
1.66GHz GNU/Linux

I do not use mysql_pconnect().

Thanks!

Antoni

Antoni wrote:
> Hello,
>
> I'm also using Wordpress, but it does not use that much joins either.
>
> I'm using:
>
> PHP 5
> MySQL 5.0.21-log
> Apache 2.0.59
>
> Server Specs:
>
> Linux 2.4.33grs-bipiv-ipv4-32 #1 i686 Intel(R) Core(TM)2 CPU T5500 @
> 1.66GHz GNU/Linux
>
> I do not use mysql_pconnect().
>
> Thanks!
>
> Antoni
>

Antoni. Check out some documents on MySQL tuning. You might have too
little RAM allocated, or some other tuning information. A good place to
start would be
http://mysqldatabaseadministration.b...ing-guide.html

Good luck.