[SOLVED] We'd like your help

jeremy · 06-29-2009, 01:27 PM

As you may know, LQ has utilized a CDN (content distribution network) to speed static content delivery for some time. We're considering switching, however, and would like to see which CDN is the fastest for LQ members. Below I've included three pages that load multiple images from each CDN. We'd like your feedback on which images load the fastest and are cached the best from your location. I've also included a page that loads all images from a local LQ URL as a reference point. Thanks for the feedback.

CDN
http://images.linuxquestions.org/cdntest/cdnl.html
http://images.linuxquestions.org/cdntest/cf.html
http://images.linuxquestions.org/cdntest/front.html

local to LQ
http://images.linuxquestions.org/cdntest/local.html

--jeremy

johnsfine · 06-29-2009, 01:50 PM

Any particular test you suggest we try?
Simply clicking on them, each of the four loads too fast for me to see the difference.
Do you know a good tool for timing how very fast a tiny image loads? Or are you just worried about people in odd corners of the internet where those don't all load fast? Or should you have provided harder test images? Or am I totally missing the point?

jeremy · 06-29-2009, 01:54 PM

Realistically, all four should be similar if you're in the USA and on broadband. The benefits of a CDN come in pushing the content closer to the user and more aggressive caching. It's possible that this test is a bit too simple. If that's the case I'll create a page that loads a bunch of images from each CDN - which is closer to how things actually work at LQ in the real world.

--jeremy

mdg · 06-29-2009, 01:57 PM

url 1 - 0.36 sec
url 2 - 0.37 sec
url 3 - 1.33 sec
url 4 - 1.12 sec

Using Fasterfox page loading timer

cmnorton · 06-29-2009, 01:58 PM

If an eye blink determines speed, then cachefly was the slowest. I could barely tell, though.

samnjugu · 06-29-2009, 02:01 PM

I think we might need a bigger image, they all load too fast to notice any difference.

jeremy · 06-29-2009, 02:06 PM

I've updated the first post with a page that loads multiple images from each. Thanks for the feedback so far.

--jeremy

win32sux · 06-29-2009, 02:06 PM

Code:

win32sux@candystore:/tmp$ wget http://http.cdnlayer.com/lq/images/questions/images/LinuxQuestions.png
--2009-06-29 14:02:43--  http://http.cdnlayer.com/lq/images/questions/images/LinuxQuestions.png
Resolving http.cdnlayer.com... 69.88.152.250
Connecting to http.cdnlayer.com|69.88.152.250|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 20870 (20K) [image/png]
Saving to: `LinuxQuestions.png'

100%[===================================================================================================================>] 20,870      56.9K/s   in 0.4s    

2009-06-29 14:02:44 (56.9 KB/s) - `LinuxQuestions.png' saved [20870/20870]

win32sux@candystore:/tmp$ wget http://linuxquestions.cachefly.net/images/questions/images/LinuxQuestions.png
--2009-06-29 14:02:56--  http://linuxquestions.cachefly.net/images/questions/images/LinuxQuestions.png
Resolving linuxquestions.cachefly.net... 205.234.175.175
Connecting to linuxquestions.cachefly.net|205.234.175.175|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 20870 (20K) [image/png]
Saving to: `LinuxQuestions.png.1'

100%[===================================================================================================================>] 20,870      48.8K/s   in 0.4s    

2009-06-29 14:02:57 (48.8 KB/s) - `LinuxQuestions.png.1' saved [20870/20870]

win32sux@candystore:/tmp$ wget http://d1d4g485pex8zi.cloudfront.net/images/questions/images/LinuxQuestions.png
--2009-06-29 14:03:09--  http://d1d4g485pex8zi.cloudfront.net/images/questions/images/LinuxQuestions.png
Resolving d1d4g485pex8zi.cloudfront.net... 216.137.33.55, 216.137.33.166, 216.137.33.213, ...
Connecting to d1d4g485pex8zi.cloudfront.net|216.137.33.55|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 20870 (20K) [image/png]
Saving to: `LinuxQuestions.png.2'

100%[===================================================================================================================>] 20,870      51.4K/s   in 0.4s    

2009-06-29 14:03:10 (51.4 KB/s) - `LinuxQuestions.png.2' saved [20870/20870]

win32sux@candystore:/tmp$ wget http://images.linuxquestions.org/CDN/images/questions/images/LinuxQuestions.png
--2009-06-29 14:03:26--  http://images.linuxquestions.org/CDN/images/questions/images/LinuxQuestions.png
Resolving images.linuxquestions.org... 208.101.3.245
Connecting to images.linuxquestions.org|208.101.3.245|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 20870 (20K) [image/png]
Saving to: `LinuxQuestions.png.3'

100%[===================================================================================================================>] 20,870      62.6K/s   in 0.3s    

2009-06-29 14:03:26 (62.6 KB/s) - `LinuxQuestions.png.3' saved [20870/20870]

win32sux@candystore:/tmp$

I do think it's tough to get an accurate representation with an image this small, though.

Could you make one that is one or two megabytes?

jeremy · 06-29-2009, 02:10 PM

win32sux, I updated the test to include multiple images. The reason I didn't put up a single large file is that in the real world, that's not how we use the CDN. A single large file is going to test throughput, which we really don't care about much. Latency on a bunch of smaller files is a better indicator for our usage pattern.

--jeremy

win32sux · 06-29-2009, 02:12 PM

Quote:

Originally Posted by jeremy

win32sux, I updated the test to include multiple images. The reason I didn't put up a single large file is that in the real world, that's not how we use the CDN. A single large file is going to test throughput, which we really don't care about much. Latency on a bunch of smaller files is a better indicator for our usage pattern.

Roger that.

custangro · 06-29-2009, 02:15 PM

Quote:

Originally Posted by jeremy

As you may know, LQ has utilized a CDN (content distribution network) to speed static content delivery for some time. We're considering switching, however, and would like to see which CDN is the fastest for LQ members. Below I've included three pages that load multiple images from each CDN. We'd like your feedback on which images load the fastest and are cached the best from your location. I've also included a page that loads all images from a local LQ URL as a reference point. Thanks for the feedback.

CDN
http://images.linuxquestions.org/cdntest/cdnl.html
http://images.linuxquestions.org/cdntest/cf.html
http://images.linuxquestions.org/cdntest/front.html

local to LQ
http://images.linuxquestions.org/cdntest/local.html

--jeremy

http://images.linuxquestions.org/cdntest/cdnl.html

^ Was the fastest for me.

-C

SkyEye · 06-29-2009, 02:18 PM

Loading in the browser wasn't quite effective as the 1st image in the link is already cached (it's the LQ.org logo I see at the top of the page). On a second test the first one seemed the fastest. I checked with wget and cloudfront link was faster than cdnlayer. And cachefly was usually the slowest in the tests.

Here are rough values after multiple runs of wget. The values changed a lot. These are just the values with the highest frequency. (For the earlier posted image links)

cdnlayer - 0.7s
cachefly - 1.1s
cloudfront - 0.6s
LQ local - 0.8s

EDIT: After jeremy updated the links, I checked again. The values changed, but the patterns remained same.

I'm from Sri Lanka, BTW.

jeremy · 06-29-2009, 02:24 PM

I'll update the cdnlayer (which we currently use) page to not load images that may already be cached.

--jeremy

win32sux · 06-29-2009, 02:26 PM

Quote:

Originally Posted by SkyEye

Here's are rough values after multiple runs of wget. The values changed a lot. These are just the values with the highest frequency. (For the earlier posted image links)

cdnlayer - 0.7s
cachefly - 1.1s
cloudfront - 0.6s
LQ local - 0.8s

What command line options are you giving wget?

I'm using "wget -p" but it only downloads the images on the local test.

jeremy · 06-29-2009, 02:37 PM

You'll need to use wget -pH (since the links span multiple hosts when not using the "local" link).

--jeremy