Website and Server Administration Forum

**danifer** · 07-27-2006, 12:56 AM

I've had some complaints of a possible DNS issue on some of my sites. The chief culprit seems to be danifer.com which one time in ten will take up to 15 seconds or more to resolve. Once resolved, the pages load quickly.

Please take a moment to hit my site and report the results here. Stats for your connection speed, physical location and initial load time would all be very useful. Your help is much appreciated and suggestions to correct the issue are welcome.

http://www.danifer.com/

**Hoang** · 07-27-2006, 01:23 AM

I'm on DSL and it took me about 15 seconds to load up the page and I'm located in Louisiana. Is that what you wanted to know?

**danifer** · 07-27-2006, 01:25 AM

Yes, you rock. Much obliged.

**Sobering** · 07-27-2006, 01:59 AM

It loaded fast from the start for me.

**Tran** · 07-27-2006, 03:03 AM

Site loaded right away.. Don't know why it has been taking you 15 seconds.. I'm in Utah and on Cable

**nmau** · 07-27-2006, 08:09 AM

Site fully loaded in 5 seconds for me. I'm on ADSL in Australia

**danifer** · 07-27-2006, 11:44 AM

Quote:

Originally Posted by dave

Site loaded right away.. Don't know why it has been taking you 15 seconds.. I'm in Utah and on Cable

I'm thinking this is an intermittent issue with my nameserver. Testing it from multiple locations should give an idea as to the frequency of the problem, and if there are any other variables (like peak traffic times) that may be having an effect.

Thanks to all for your continued feedback!

**Atomm** · 07-27-2006, 03:24 PM

Danifer,

I do not think your problem is what you think. Let me explain why.

When I query a domain through FireFox, the query is sent to my local DNS server. 9 times out of 10, the domain is cached. That means I never have to contact your NameServer to get your IP. Thus, your own DNS rarely comes into play.

Even the 1 time it is not cached should not take anywhere near 15 seconds.

I have seen delays like you describe when MySQL is involved and not optimized correctly for the hardware it is running on. I have also seen problems like that when the HTTP threads were maxing out.

You might take a look at those issues.

**danifer** · 07-27-2006, 07:53 PM

Quote:

Originally Posted by Atomm

I have seen delays like you describe when MySQL is involved and not optimized correctly for the hardware it is running on. I have also seen problems like that when the HTTP threads were maxing out

Atomm, can you elaborate on these points? Where would I look for warning signs and how would I resolve them?

**Zepfu** · 07-27-2006, 08:22 PM

About 1.5 seconds to load. Not exactly the best response time by a far cry from the 15 seconds others are experiencing. cable in the south east.

**danifer** · 07-28-2006, 11:25 AM

Thanks everyone for helping me test!

Atomm - I've made some changes to the server configuration per your recommendations. Check out the blog post for the full story - I think a lot of it had to do with the Apache2 MaxClients setting.

Do you know of anyway I can see the number of HTTP requests or client connections being served at a time?

**Atomm** · 07-28-2006, 01:15 PM

Sure.

ps -aux|grep http|wc -l

That last character is a lowercase L. That will count the number of lines with http from the output of a ps. Keep in mind, running that command ads one http to the number, so subtract one.

You can drop the |wc -l to see all of the http lines. I do that sometimes to see which site is getting the most current hits. It doesn't always work because sometimes apache runs as the site user and sometimes it runs as it's designated user.

If you want to pause the list of lines, use this command:

ps -aux|grep http|less

Just hit the space bar to continue.

To see which processes are using the most resources, you can use the command top. It will show you memory, swap and CPU usage. Think of it as Task Manager for Linux.

Glad to have helped.