IGT cloud computing Workgroup

Hi
Next Monday (20-Apr-09 14:00-17:00 IDT) I am going to present a case study which will discuss the benefits of performing application load test in the cloud. My presentation will take place in IGT offices in Herzelia and will be part of a meeting of the Israeli cloud computing work group along with two other sessions of Nati Shalom CTO of GigaSpaces and Moshe Kaplan CEO of Rocketier. Registration is free just send an email to info@grid.org.il.
For more information on my session and other session in the WG meeting follow this link
http://www.grid.org.il/?CategoryID=384&ArticleID=137&Page=1

Hope to see you there....

Nice enhancement of JDK1.6.0_14

From JDK1.6.0_14 a stack trace dump is added to a hprof memory snapshot this can help profilers display thread and stack is shown for GC roots of types "Stack Local" and "JNI Local".
Yourkit 8.0.3 already utilizes this feature.
Nice!

Yet another reason to move to JDK 1.6

My first production memory leak analysis with Java 1.6 was almost a very pleasant experience.

While in previous versions of java I  needed to restart the JVM and set appropriate profiler command line option,  Java 6 comes with a built in alternative.  jmap which was not available for Windows distributions is now available for use. Taking a memory snapshot is a point and click task:

jmap -dump:format=b,file=dump.hprof

Take  the hprof dump generated and use you favorite profiler to analyze it.

If you are only interested in a short summary of memory usage by class:

jmap -histo

So, why was it only an almost pleasant experience ? Because you need to make sure that you are connected to the same windows session as the process you are trying to dump. If you are using terminal services make sure you use the /console command line option, otherwise jmap will not work. Beats me why.. 

10 People - a Billion USD revenue

I have been attending this week to the"World summit of cloud computing" which was quite an impressive conference compared to other Israeli conferences I have been to with representatives from Google,HP,Intel,Amazon,EBay, Yahoo,SUN, Salesforce, GridGain, Forrester,GigaSpaces, MerrilLynch and more. Each one of those vendor has a different definition and point of view so after those two days I am ready to give my own definition and what it means to me.
So, Cloud computing is a deployment option for your application which has the following four characteristics:

Outsourced
Your run your stuff on other people machines and infrastructures(IaaS). These resources can be conזsumed either from the the intranet for small large enterprises and government use or reside in the in the Internet for small/midsized companies. But the main issue here is that all you pay for the infrastructure in that case is money.

Economical
Using this deployment option should save you money and possibly a lot of money.

• Reduced CAPEX:, meaning money you will need to invest upfront inoder to support the expected and unexpected changes in capacity.

• Reduced OPEX: Let cloud providers do what they do the best, maintain large machine infrastructure. Hopefully (with the right amount of competition) that will reduce your IT OPEX.
  
• New financial model: All the ?aaS concept is presuming a different(and more fair) revenue model compared to what we are used to in the traditional software industry you only pay for the resources you use no payment upfront and not commitment for long term.
  

Elastic
You are able to adjust seamlessly the amount of infrastructure you consume. This helps you handle peaks more efficiently. You no longer need to choose between compromising on your SLA in peak times or let your servers rot in the cellars when you really don't need them.

SelfService
You as a developer(and I am intentionally focusing on developers) are able to allocate and deallocate resources by yourself through an API no need to sign forms no paperwork. You can write on use software which will do the job for you.


And not to my thoughts:
So I have a crazy vision regarding this new concepts what I see in my mind is a billion USD internet company with a size of 10 people which altogether bring unique (probably patented) value and all their job is to orchestrate outsourced resources to the benefit of the company.
A CEO - orchestrating vision and execution with a set of VAs
VP sales - orchestrate sales operation through an effective network affiliation
VP infrastructure - manages the application in the cloud
VP support - orchestrate outsourced call center and
VP finance
VP R&D -
4 developers - developing only core business logic consuming open source projects for the other stuff.

I know it is a bit extreem but I don't care I am sure it will happen one day.

IGT 2008 next week

The world summit of cloud computing is taking place in Israel next week.
I have big expectations toward this summit as I believe that the future is in the cloud.
This is not an affiliation link :-) you are welcome to register I'd love to see you there!
http://www.cloudcomputing.org.il/index.html

Last post Recall or why use HTTP1.1

Today I saw that Ford are recalling 1000 cars due to problems in steering wheel liquid. This makes me feel a bit more comfortable about the need to take back what I said just few days ago :-).

So why do I need to recall the post. Not because SSL connection establishment is not expensive. It is indeed. The issue is that HTTP1.1 (opposed to HTTP1.0)  can pool the connections and reuse them for later requests thus diminishing the effect of HTTPS latency).

So why the Apache web server was not behaving well (and put me into confusion)? Configuration .....

The AWS was configured to use HTTP1.0 for HTTPS connection under Internet explorer.

I did not understand yet why(an issue for a later post)  is it so, probably bugs in older versions of IE. Anyway commenting out the following lines in httpd-ssl.conf  brings back the missing .1:

BrowserMatch ".*MSIE.*" \

   nokeepalive ssl-clean-shutdown \

   downgrade-1.0 force-response-1.0

And voila after that only one roundtrip for SSL requests.....

Absolutely great :-)

Speed of light vs SSL

(Please see next post for update)

I have been trying to measure WAN efffect over an application I am working on. Due to a bug the application was running in SSL and I was quite surprised by the results.
After investigating it a little I want to share with you the following information. https (SSL) requests to the server involve two extra round trips for certificate authentication and key exchange. As a result a short HTTP request will require 3 times the network round trip time (6 times the latency). For example if latency is 90 ms and server time is 20ms https request will be 90*6+20= 560ms. While an http request will require 200ms. Quite impressive difference.
Saying that it is extremely important to reduce number of https requests to a server combining https requests is 3 times more important than regular http requests.