[CentOS] [Fwd: Server is overloaded, any tips?]

Tue Dec 12 19:01:09 UTC 2006
Administrator <administrator at insurancejournal.com>

I apologize for being vague and demanding, I have an earnest desire to 
learn, and I hope that my learning will benefit others.

Let me try to approach this problem again:

I was hoping that someone could point me in the direction of some 
helpful ways to analyze this (Centos 4.3) system. It was acting very 
strangely yesterday. I received emails complaining that:
- none of the links were working (it was a vague complaint)
- the javascript version of our RSS feed had a 14 second load time
( http://www.insurancejournal.com/newsfeed/feed.php )

I have never had to track down a problem like this and i have spent a 
good deal of the morning looking into options for the 'top' command, 
(because i had read in a Novel book that it was useful for diagnosing 
bottlenecks). I saw that there were a lot of mysql and httpd processes 
going, but i figured that was just lots of people visiting the site, or 
editors working on stories.

After not being able to find anything helpful (that i could take action 
on), I ended up trying the vmstat command (got the idea here: 

The websites are set up to have their own log files, which are quite 
numerous so I ran the command:

find . -type f -printf '%TY-%Tm-%Td %TT %p\n' | sort |less

from the logfiles directory to see which one has been modified last, 
then I looked at the most recent logfile with a 'tail -f' and saw that 
it was being written incredibly fast.

the repeating error was:
File does not exist: /var/www/www.insurancejournal.com/web/news

it was my understanding that this was not a directory and it was just 
done through some sort of URL re-write.

Continuing to try to trouble shoot the issue i created the news 
directory. The error then changed to:
File does not exist: /var/www/www.insurancejournal.com/web/news/east
File does not exist: /var/www/www.insurancejournal.com/web/news/west
and so on.
Part of the reason for re-writing URLS (at least one reason I like it) 
it that you can make one PHP file look like a ton of HTML files. I could 
see that something is likely to be wrong with the re-write system, but I 
am wondering what suggestions (tools) some of the 'more seasoned' system 
admins might have to help me track down this issue or even a better 
approach to problem solving.

Any tips would be greatly appreciated.

Many Thanks

Walt Reed wrote:
> On Tue, Dec 12, 2006 at 09:36:08AM -0800, Administrator said:
>> Yesterday our website was acting a little odd, and i received a few
>> email complaints. Running 'top' showed that we had a very high load
>> average, today the load average is even higher!
>> load average: 13.18, 12.49, 10.48
>> It is pretty unlikely that our site grew in popularity that quickly, and
>> taking a look at the log file it was saying that a certain directory was
>> not found, when in fact it was just a mod-re-write rule and was not
>> supposed to exist. The website works fine... i am stumped and the error
>> log is getting quite big! Does anyone have any tips on how to find the
>> problem and address it accordingly (quickly)?
>> Many thanks
> Patient: Doctor, I am ill, but I can't tell you any details. What can I
> do to feel better?
> Doctor: Well, it would be helpful if you give me some more details, or
> I could ask you about 10,000 questions and we can be here all month...
> Seriously, please read:
> http://linuxmafia.com/faq/Essays/smart-questions.html
> Then look at your log files. The contents will probably give you your
> answer anyway.
> Thanks.
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos

Noah Spahn
Tech Manager/Systems Administrator
Wells Publishing Inc
(619)584-1100 ext.122