Swap memory usage

newbie14 · 01-25-2015, 10:15 PM

Hi,
I have mysql server which is purely just to server mysql db. I notice my top is showing as below. The server have been running for some time now. I notice the swap memory is used is that some indication of abnormality? The resident memory of mysql is almost 2.3g is that also something to worry?

Code:

top - 12:09:46 up 455 days, 15:46,  1 user,  load average: 0.37, 0.25, 0.09
Tasks: 215 total,   1 running, 214 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.0%us,  0.1%sy,  0.0%ni, 99.8%id,  0.1%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   7990916k total,  7326968k used,   663948k free,   158608k buffers
Swap:  8126456k total,   188244k used,  7938212k free,  3920680k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
  130 root      39  19     0    0    0 S  0.3  0.0   2538:43 kipmi0
10240 root      20   0 15136 1384  984 R  0.3  0.0   0:00.02 top
31654 mysql     20   0 8306m 2.6g 4444 S  0.3 34.8   1200:13 mysqld
    1 root      20   0 19228  712  520 S  0.0  0.0   0:00.94 init

unSpawn · 01-26-2015, 03:26 AM

Quote:

Originally Posted by newbie14

I notice the swap memory is used is that some indication of abnormality? The resident memory of mysql is almost 2.3g is that also something to worry?

Please read http://www.linuxatemyram.com/. Regardless of if there is an imminent performance problem or not, do start tracking resource usage over time using Atop, Dstat, Collectl (heya Mark), Nagios or Zabbix and then look at value changes (trending) in about a week or a month. If you experience performance problems then first look at the log files for clues, start slow query logging, run mysqltuner and check the MySQL documentation about performance tuning / troubleshooting and recommendations. Do not arbitrarily change any values but ensure you have enough monitoring data to be able to see the effect of the changes you are making. If unsure provide pertinent details and ask detailed questions first.

syg00 · 01-26-2015, 03:46 AM

Quote:

Originally Posted by newbie14

I notice the swap memory is used is that some indication of abnormality?

Slightly over 2% usage - hardly cause for concern I would have thought. Especially as "The server have been running for some time now".

Quote:

The resident memory of mysql is almost 2.3g is that also something to worry?

What did you purchase the memory for, if not mysql ?

newbie14 · 02-12-2015, 04:24 AM

Dear Unspawn,
Sorry for the late reply. I was doing some read up about the list of softwares you mentioned. I dare not try those with webgui based on my previous experience where you suggest to stay away. I saw a lot of people are talking about this Collectl as a good solution. So I would like to ask must I do a installation to fully monitor it as times goes or just run it on certain interval period?

---------- Post added 02-12-15 at 06:25 PM ----------

Dear Syg
Yes the memory is purely for Mysql as its only used for mysql server nothing else.