Memory usage on Ubuntu Desktop 12.04 64 bits

[icaka92]

Stop work mean that when i try to load the site with browser, I can't. It takes too long to respond.

Type of site: Dynamic content with a database behind it.
Database: Mysql
Webserver: Apache

When i run command:

top

i receive this:
top - 15:52:05 up 11:21, 1 user, load average: 9.16, 6.43, 5.89

Tasks: 195 total,   8 running, 187 sleeping,   0 stopped,   0 zombie
Cpu(s): 89.8%us,  9.2%sy,  0.0%ni,  0.3%id,  0.0%wa,  0.0%hi,  0.7%si,  0.0%st
Mem:   8161688k total,  7344168k used,   817520k free,   117612k buffers
Swap:  8370172k total,        0k used,  8370172k free,  6308200k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  515 mysql     20   0 2464m 105m 7444 S  174  1.3  16:16.88 mysqld
13888 www-data  20   0  161m  31m 5472 R   99  0.4 377:15.31 ffmpeg
12936 www-data  20   0  153m  23m 5040 R   98  0.3 399:06.39 ffmpeg
 1910 www-data  20   0  152m  21m 5228 R   60  0.3   0:04.11 ffmpeg
 1828 www-data  20   0  166m  38m 5772 R   47  0.5   1:13.89 ffmpeg
 1909 www-data  20   0  133m 6592 4496 R   39  0.1   0:03.21 ffmpeg
 1836 www-data  20   0  158m  26m 5264 R   37  0.3   1:04.56 ffmpeg
 1603 www-data  20   0  134m 8372 4904 S   32  0.1   0:39.91 ffmpeg
 1898 www-data  20   0  134m 8004 4896 S   11  0.1   0:02.67 ffmpeg
  741 www-data  20   0  471m  13m 4388 S    0  0.2   0:00.06 apache2
  794 root      20   0     0    0    0 S    0  0.0   0:00.13 kworker/1:1
 1892 www-data  20   0  469m  14m 4308 S    0  0.2   0:00.03 apache2
 1923 www-data  20   0  471m  13m 4232 S    0  0.2   0:00.01 apache2
 1924 www-data  20   0  470m  13m 3852 S    0  0.2   0:00.01 apache2
    1 root      20   0 24440 2424 1356 S    0  0.0   0:01.22 init
    2 root      20   0     0    0    0 S    0  0.0   0:00.00 kthreadd
    3 root      20   0     0    0    0 S    0  0.0   0:00.44 ksoftirqd/0

No erros in mysql error log.
In apache log there are only information about ffmpeg converstion.

[CharlesA]

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  515 mysql     20   0 2464m 105m 7444 S  174  1.3  16:16.88 mysqld
13888 www-data  20   0  161m  31m 5472 R   99  0.4 377:15.31 ffmpeg
12936 www-data  20   0  153m  23m 5040 R   98  0.3 399:06.39 ffmpeg
 1910 www-data  20   0  152m  21m 5228 R   60  0.3   0:04.11 ffmpeg
 1828 www-data  20   0  166m  38m 5772 R   47  0.5   1:13.89 ffmpeg
 1909 www-data  20   0  133m 6592 4496 R   39  0.1   0:03.21 ffmpeg
 1836 www-data  20   0  158m  26m 5264 R   37  0.3   1:04.56 ffmpeg
 1603 www-data  20   0  134m 8372 4904 S   32  0.1   0:39.91 ffmpeg
 1898 www-data  20   0  134m 8004 4896 S   11  0.1   0:02.67 ffmpeg

Is apache supposed to be running ffmpeg?

[jerome1232]

also a load average of 9 how many cores do you have, sounds like your CPU is pegged and that's why your site is unresponsive.

[CharlesA]

also a load average of 9 how many cores do you have, sounds like your CPU is pegged and that's why your site is unresponsive.

From their OP, it looks like it's a hex core CPU.

I have a feeling the load is that high because ffmpeg is running 8 times, all as www-data, which shouldn't be launching ffmpeg, as far as I know...

[icaka92]

CPU : AMD FX-6200 /3.8G/X6/BOX AM3+
Many users use ffmpeg to convert at same time. This can be the problem or no ? And if this is the problem how to correct it ?

Thanks !

[CrucifiedEgo]

CPU : AMD FX-6200 /3.8G/X6/BOX AM3+
Many users use ffmpeg to convert at same time. This can be the problem or no ? And if this is the problem how to correct it ?

Thanks !

Yes, this would be the problem. I assume your site is calling ffmpeg to convert video. Video conversion is very, very CPU and RAM intensive and what's most likely happening is that there are too many conversions happening at once. If there are more than 6, then your CPU can't really keep up and will stop responding while it tries to chug through all the video data. You'll either need to reprogram the site to queue video conversions and limit them to 4 or 5 at a time, or add more CPU cores to your server (though there are very diminishing returns on that as the highest you'd be able to go with that platform is 8 cores with an FX-8xxx CPU.

EDIT: perhaps this will be helpful in reorganizing your application: http://ffmpeg.org/trac/ffmpeg/wiki/U...0PHP%20scripts

[sandyd]

Small explanation in order.

Immagine each CPU is a checkout line at the supermarket.

Each = represents full processor utilization, and is equal to 1.0 load in linux.


So, if you have two lines, it looks like this


------------------
==================
------------------
==================
------------------

And if you have more lanes, and so on.

Now, If you have four processors, and a load of 8, it will look something like this


------------------
==
------------------
==
------------------
==
------------------
==
------------------

The second = (after the first) shows that there is exactly 4.0 loads waiting to process ( one on each processor due to SMP).

That means that there are tasks queued to run on the processor, but cannot due to the fact that the processors are still processing the first =. Those tasks will be queued until some of the tasks in the first '=' finish running.

As a result, you are experiencing very slow response times- your query is queued somewhere in the line

[icaka92]

Hello,

Thanks you for help ! I try

http://ffmpeg.org/trac/ffmpeg/wiki/Using%20FFmpeg%20from%20PHP%20scripts

, but it is the same. I don't know how to correct it to work okay

[icaka92]

Any ideas ?

[CrucifiedEgo]

Any ideas ?

Yes, fix your code and buy more hardware, your site is taxing the server and it can't handle the load.