Diagnosing Page load Issues

**thecoalman** · 11-20-2010, 04:22 AM

I have an issue where I get extremely long page loads intermittently, 15 to 30 seconds or might just not load at all.

Looking over the http, mysql and other logs I don;t see anything to indicate any problems.

Previously the server I was on the load hovered around .1. I believe the server load shown in top is entire server and not just my VPS? On this one it appears to be constantly at .2 or above, I've seen it spike to 5.2.

What I observe while watching top is the CPU will steadily increase and once it gets around 1.2 I'll see issues with slow page loads. There doesn't appear to be anything abnormal in the process list.

This was actually after it spiked to about 2.0, what will happen is I'll see all processes listed at 0% and then a whole bunch of http process will open up simultaneously presumably to fill the requests backed up?

CPU issue? Bandwidth issue? Where to look next.

I'm assuming if I disable the domain I could observe top to see if these spikes continue?

**Ron** · 11-20-2010, 02:12 PM

In the top output, ALL of your load is in wait I/O.
Since MySql is showing at the top, I would look first at disk resources; test the theory by down loading the same flat file repeatedly to rule in/out NIC bandwidth issues.

Assure your own dbs are in order with the MySql optimize function. Time MySql dumps. All to get a picture of what takes longer when you're seeing the issue.

Once you're done, then you can present your findings to support, and stick to your guns. But unfortunately on a VPS YOU don't have the ability to see what it going on at the server level and will need to depend on support to diagnose issues caused by other customers.

**Vin DSL** · 11-20-2010, 11:10 PM

Originally Posted by Ron

Assure your own dbs are in order with the MySql optimize function. [...]

Personally...

I would use the 'check' function in phpMyAdmin, first. If the dbs are ralphed, then I would use the 'repair' function.

Otherwise, you crystallized my thoughts, exactly...

**Ron** · 11-21-2010, 01:31 AM

I thought optimize did an automagic repair if necessary...? I dunno where I heard that. Anyway, I seem to think that optimize rewrites the entire table to new disk space, so if there was a problem with a sector, you might get lucky that way too.

**thecoalman** · 11-21-2010, 12:53 PM

Since MySql is showing at the top, I would look first at disk resources; test the theory by down loading the same flat file repeatedly to rule in/out NIC bandwidth issues.

I have top sorted by CPU usage and in this case mysql was just finishing. I'm thinking it might be bandwidth problem as you are suggesting. I get very inconsistent download speeds for large files and I'll see it drop from an initial 300kbps to 30kbps and stay there in lot of cases. I get timeouts on large files too.

I already optimized all tables with overhead before I posted this, there was only a few. Overhead is fragmented tables ?

I'll run the check function.

The thing is there isn't anything I've changed in months and I'm not seeing anything out of the ordinary for traffic usage.

**thecoalman** · 11-21-2010, 02:25 PM

I ran the check function and didn;t see any problems.

I also ran the optimize function on every table, I'm guessing now my original assumption about the overhead was wrong?

I'll see what happens...

**thecoalman** · 11-22-2010, 07:43 AM

Didn't help.

Can somebody test this for speed , I'm getting 30 to 100KB/s tops.

http://nepacrossroads.com/download/file.php?id=18951

**JPC-NickO** · 11-22-2010, 07:44 PM

Hi,

I downloaded this using my home connection (located in Canada) which maxes out at 768 KiB/s.

$ wget http://nepacrossroads.com/download/file.php?id=18951
--2010-11-23 02:36:01-- http://nepacrossroads.com/download/file.php?id=18951
Resolving nepacrossroads.com... 69.73.146.169
Connecting to nepacrossroads.com|69.73.146.169|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 24947646 (24M) [application/octet-stream]
Saving to: “file.php?id=18951”

100%[======================================>] 24,947,646 338K/s in 77s

2010-11-23 02:37:19 (315 KB/s) - “file.php?id=18951” saved [24947646/24947646]

**thecoalman** · 11-22-2010, 08:01 PM

I'm getting 200KB/s right now but I'll go to try it some other time and it's going to drop. I get speeds all over the place from one file I observed that slowed to 20KB/s to another that maintained 275KB/s. I've had them timeout too and I'll have truncated download.

This also applies to regular files not served through PHP script so that is not the issue either. As I pointed out in my ticket Google shows significant increase in download time over the last week and I have a bunch of people complaining about the slow and no page loads. It's not just me.

**Ron** · 11-22-2010, 08:17 PM

For what it's worth, Google has been lightly complaining about increasing load time on my site from more than 1,000 data points....

**Ron** · 11-22-2010, 08:20 PM

Do you have a flat file I can try? I have a very fast connection.

Edit: I got 1.04 mB/Sec on my netbook over wifi on my 20mbps connection.

NEPAdownloadTest.jpg

**thecoalman** · 11-22-2010, 08:46 PM

Originally Posted by Ron

For what it's worth, Google has been lightly complaining about increasing load time on my site from more than 1,000 data points....

I have had a pretty flat line for 2 years except the occasional spike, the bot downloads about 2000 pages a day so it's a very good sample amount. The traffic at the end of October is about the same it is now. This is download speed in milliseconds.