Server become too slow

yeazas · February 18, 2008, 9:49pm

Hi,
Since last week our server become too slow when we try to run application on it. When we run top command, it show as below:

System: xxxxxx Mon Feb 18 10:56:14 2008
Load averages: 21.60, 21.56, 21.55
120 processes: 97 sleeping, 21 running, 2 zombies
Cpu states:
LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
21.60 45.4% 0.0% 54.6% 0.0% 0.0% 0.0% 0.0% 0.0%

Memory: 383576K (112220K) real, 367628K (107192K) virtual, 1138632K free Page#
1/3

TTY USERNAME PRI NI SIZE RES STATE TIME %WCPU %CPU COMMAND
? 16671 root 222 20 168K 212K run 10:56 4.94 4.93 asasd
? 16695 root 222 20 168K 224K run 10:47 4.91 4.90 asasd
? 16567 root 223 20 168K 224K run 10:41 4.89 4.88 asasd
? 16583 root 223 20 168K 220K run 10:54 4.87 4.86 asasd
? 16615 root 223 20 168K 188K run 10:55 4.86 4.85 asasd
? 16631 root 223 20 168K 212K run 10:54 4.85 4.84 asasd
? 16591 root 223 20 168K 188K run 10:56 4.82 4.82 asasd
? 16663 root 223 20 168K 224K run 9:28 4.80 4.79 asasd
? 16711 root 223 20 168K 212K run 10:49 4.78 4.77 asasd
? 16575 root 222 20 168K 212K run 10:55 4.76 4.75asd
? 16679 root 222 20 168K 220K run 10:55 4.68 4.67 asasd
? 16655 root 223 20 168K 224K run 10:50 4.66 4.65 asasd
? 16607 root 223 20 168K 188K run 10:54 4.65 4.64 asasd
? 16687 root 221 20 168K 188K run 10:52 4.64 4.63 asasd
? 19366 root 223 20 200K 220K run 1:04 4.61 4.60 asasd
? 16559 root 223 20 168K 220K run 10:58 4.61 4.60 asasd
? 16639 root 223 20 168K 212K run 10:56 4.61 4.60 asasd
? 16703 root 223 20 168K 212K run 10:50 4.58 4.57 asasd
? 16599 root 168 20 168K 224K sleep 10:45 4.00 3.99 asasd
? 16540 root 152 20 2364K 7304K run 14:33 3.96 3.95 java
? 16623 root 168 20 168K 220K sleep 10:54 3.61 3.60 asasd
? 17720 www 154 20 24404K 21592K sleep 1:18 1.98 1.98-httpd
? root 152 20 0K 0K run 0:24 0.90.92 0.92fsd
pts/tc 19888 root 168 20 3416K 648K run 0:00 0.20 0.18 top

So it's nothing to do with heavy utilization, right? Can you give some opinion on what actually had happended?

Thank you very much...

Perderabo · February 18, 2008, 10:29pm

You have 20 asasd processes running and each one is using about 5% of the system. The load average is over 20. And yet you say "it's nothing to do with heavy utilization, right?". Well that looks pretty heavy to me.

yeazas · February 19, 2008, 3:55am

Hehehe..actually I do not understand when should we decide that server is heavy utilization or not. From what I believe and understand, since the CPU LOAD average is still not reach 100%, the server is still considered ok. Hopefully you can help to expalin on how to decide that server is heavy utilize or not. Thank you...

Perderabo · February 19, 2008, 5:56am

Well, when you say (as you did in your first post) "Since last week our server become too slow" that is a pretty good clue. Pay attention when the users of a system say that they notice a difference.

Load average is the average number of processes that want a cpu (or will want want a cpu very soon) but cannot get one. But it also includes currently running processes (since they too must want a cpu). It is not a percentage. 20 is generally very high but with enough cpu's it might be ok. If you had 32 cpus, some of them would be idle and you would have no problem at all.

The percentages are indicated by this symbol % (which we call a per cent sign). Look at your idle percentage. It is zero. That means you are maxed out. Adding cpu's would probably help.

yeazas · February 19, 2008, 8:59pm

Ooo..i see.. Thanks Perderabo. I really appreciate your explanation and your help Now I understand on how to see those thing especially on resources utilization

Thanks once again...