Sajal Kayan

4 reasons why I love my ISP

November 29th, 2011

I’ve been using True ADSL for years, and I absolutely love their service (and especially the transparent proxy). Here are some of the reasons why :-

Censorship Protecting me from bad stuff – Interwebs has a lot of “bad” things out there. My ISP takes good care of me by not letting me access things I am not supposed to see… Even sites not explicitly blocked by court-order. I don’t know what I would do without them. My head would probably explode if I saw porn, and my feelings would get hurt if I came across certain types of political messages..

Transparent proxy Web slow down machine – Buddha teaches us “The greatest prayer is patience”. A very special offering of True ISP is that it reminds us to be patient in this fast-paced world. True’s Web slow down machine sits between users’ connection to other servers. One of its features is to slow down access… It employs several brilliant methods to accomplish this :-

• Not keeping connections alive – This is the most important factor in slowing down pageloads. True does not keep connections to remote hosts alive, thus making sure you have to establish a fresh connection with each request to a server overseas. No matter how small the file, a request to the USA will take a minimum 500ms.
• Making TCP optimizations useless, since the slow down machine is the one that actually makes connections to remote hosts.
• Overriding destination IP – True doesn’t care about what IP your computer wanted to connect to, your computer could be wrong. It sees the Host header from the request, does its own DNS lookups and routes you to the correct server. Even if you wanted to override this for development, True correctly sends you to production server. True knows development/staging servers are full of bugs, so requests should always go to production.
• 512 kbps upload speed is sufficient for everyone. If you need to upload something big, why not get your lazy ass out, buy a CD and mail it!
• Sharing is caring – My ISP oversells available bandwidth by a huge margin. Teaches us the importance of sharing

Privacy People impersonator – Your life is boring? True has a solution! It will automagically log you in as someone else so you can get a glimpse into their exciting lives.

Incompetence Motivator – Living in Thailand, I am ashamed that I don’t read Thai yet, in part due to my own laziness. True gives you an incentive.

edited by Michael van Poppel

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DFP now officially supports asynchronous rendering!

October 27th, 2011

Yesterday, DFP launched asynchronous ad loading. For the past few months ive been trying to load ads in a manner where it doesn’t affect rest of the page load, this new development is like a dream come true.

(The tests above were run on webpagetest.org on IE8 at Dulles, VA)

Thank you Google! You just made my day.

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Check if you are behind a transparent proxy

October 12th, 2011

Many Asian ISPs do not provide clean internet. They route all HTTP sessions thru a transparent proxy.

Here is a simple way to check if you are behind one.

sajal@sajal-laptop:~$ ping -c 4 www.cdnplanet.com
PING www.cdnplanet.com (107.20.181.99) 56(84) bytes of data.
64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=1 ttl=42 time=314 ms
64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=2 ttl=42 time=313 ms
64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=3 ttl=42 time=312 ms
64 bytes from ec2-107-20-181-99.compute-1.amazonaws.com (107.20.181.99): icmp_req=4 ttl=42 time=312 ms

--- www.cdnplanet.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 312.195/313.229/314.137/0.889 ms

sajal@sajal-laptop:~$ ab http://www.cdnplanet.com/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking www.cdnplanet.com (be patient).....done

Server Software:        Apache
Server Hostname:        www.cdnplanet.com
Server Port:            80

Document Path:          /
Document Length:        13084 bytes

Concurrency Level:      1
Time taken for tests:   0.944 seconds
Complete requests:      1
Failed requests:        0
Write errors:           0
Total transferred:      13296 bytes
HTML transferred:       13084 bytes
Requests per second:    1.06 [#/sec] (mean)
Time per request:       943.539 [ms] (mean)
Time per request:       943.539 [ms] (mean, across all concurrent requests)
Transfer rate:          13.76 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:       21   21   0.0     21      21
Processing:   922  922   0.0    922     922
Waiting:      611  611   0.0    611     611
Total:        944  944   0.0    944     944
sajal@sajal-laptop:~$ 

My ping time to CDN Planet is 312ms, but the connection was established in just 21ms !!!!11!!1

Reasons for doing so involve : Censorship, big brother snooping, caching, hijacking users sessions , and probably more …

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Evaluating few CDN options

June 11th, 2011

Recently, I was evaluating CDN options for a client with some unique challenges. We ended up using Amazon CloudFront, but ill detail the options we looked at and what let us to this decision.

Some things to note:-

• We would serve CSS, JS, Images referred to from stylesheets and some website images thru the CDN.
• Due to the nature(trust me) of the site we expect a higher than normal miss rate. The access is spread across a wide number of urls, some may get lower hits.
• Speed is important. Website should be fast(er) from everywhere. The most important regions in order of priority are US, EU, AU and ROTW with US being most important.
• Anything on the site can change anytime, there is no build process as such. Any object anywhere can change, and change must be visible ASAP.
• Developers/designers shouldn’t be harassed to purge a file if they change something.
• CDN data usage : ~100 GB per month

The providers we looked at :-

MaxCDN: Almost sealed the deal.

Pros:-

• Cheap : $40 for first TB (must use in a year) + $99 per additional TB . On current usage rates this comes to say 0.04+ /GB.
• * Anycast/BGP routing : No way bad DNS server can mess up routing.
• Nice control panel, has a purge all option for just in case. Purges take effect almost instantly.
• Handles gzip well.
• Can have separate cache timings for caching in Browser and caching at CDN. – i.e. We can say not cache a file in browser level, but cache at CDN and purge when theres a change made.

Cons:-

• Poor global coverage. – No POP/Edge in Asia/AU – Deal Breaker
• Pages loaded same speed when testing from AU with or without CDN.

EdgeCast: Looked good at first, but poor gziping.

Pros:-

• Impressive list of networks
• Highly configurable control panel.
• Can have separate cache timings for caching in Browser and caching at CDN. – i.e. We can say not cache a file in browser level, but cache at CDN and purge when theres a change made.

Cons:-

• Gzippable files will not be gzipped for cache misses. – Deal Breaker
• Request from Edge server to origin is uncompressed.
• Expensive and wants higher commitments.
• DNS Based routing

CDNetworks: Didn’t look past price

Cons:-

• Ridiculously high price – Dealbreaker

Amazon CloudFront: WIN

Pros:-

• Testing showed our pages to be fastest from all regions when using cloudfront. YMMV
• No commitments – $0.15 – $0.2/GB (depends on where user accesses from) + negligible per request fee
• Client is already AWS user, one less account to maintain.
• No need to send gazillion emails to gazillions of people to get started. No bargaining.

Cons:-

• No POP/Edge in AU (but has in Singapore, Hong Kong and Tokyo)
• DNS based routing.
• Charges fee per request and per invalidation(purge) request.
• No control panel, invalidation requests need to be done by API only.
• Does not do gzipping, but honours Vary header and serves correct version based on what user asks.
• Can’t use querystring parameters for CDN cachebusting. CloudFront ignores querystrings.

Sidenote : Requests from CloudFront to origin are HTTP 1.0 . Nginx by default does not serve gzip to 1.0 request. gzip_http_version setting must be changed in order to use nginx as origin for CloudFront.

The system we architected adds something based on the file mtime as a part of the URL, so now we don’t need to any purges at the CDN. Also now we can have far future expires on all CDN’d objects cause if something changes, the URL would automagically change.

For us, the price and features are important, but whats more important is the results. We went with the provider with lesser features just because our pages loaded fastest with them.

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Attention skeptics: Web Performance Optimization works!

May 14th, 2011

Today, I was looking into web performance issues for a new client who wishes to remain anonymous and saw an interesting example of value provided by improving performance.

One of the first things I do when looking into a new site is look at Google Analytics to understand a little about the sites visitors. This helps in prioritizing changes which affects the majority of users.

An interesting observation :-

Pageviews for all visitors

Average Pageviews for all visitors

Adsense revenue also followed a similar path. — Screenshot not available

The reason for this effect was a simple database indexing tweak which sped up the backend performance of a very important action page on the site.

The site in question is a web application where user inputs something and gets some result. It is not a content site where pageview/user could have increased due to some interesting content being added or something. The only change was indexing of a column which should have an index right from the start.

DISCLAIMER: I did not have any role in the above improvement. This was done before my involvement. Perhaps this convinced the client to hire me. Screenshots/info shared with clients permission.

Posted in Monetizing, Webmaster Things | View Comments