Agile Bengaluru 2010

31 01 2010

Its been a week since agile bengaluru 2010. It was a really nice experience to meet J. B. Rainsberger, Jeff Patton, David Hussman, Naresh Jain and many more people all in one place. I liked the venue even though there was no wifi :P. More than anything else I really appreciate the “go green” theme. This is not a complete experience report, apologies for my laziness when comes to writing long posts.

Being a “Post Agile Conference”,  most topics were aimed at reflecting on how agile has helped us in the past and where are we going. Below are some of the sessions that I enjoyed.

Discovery and Delivery – Redesigning agility – Keynote by David Hussman. A great start to the conference.

Monkey See Monkey Do – by Naresh Jain and Sandeep Shetty – A very interesting talk that looked at some of the agile practices that have become dogma. It would have been great if we had some more time.

Outside the code – Using agile practices to drive product success – by Jeff Patton – It was nice to hear about the “Discovery” part of the agile software development. Go check out the slides.

Using Theory of Constraint and Just in time approach to coach agile teams – a workshop by J. B. Rainsberger and Naresh Jain.

Stop it or I will Bury you alive in a box – by J. B. Rainsberger – J.B. spoke about the 10 things we should stop doing in 2010.

Captain planet (Saurabh Arora) talks – Very inspiring talk on global warming. Keep up the good work dude.

Apart from this I got an opportunity to talk to Jeff Patton some time between the sessions. Spoke about how words like requirements, customers etc do not go well with software development.

I had to rush before all the lightning talks got over. Managed to listen to a some talks like “Agile Deployment”. Just before I left I spoke about “Developer + Tester + Operations = DevTestOps”.

Programming with the stars – A very entertaining session. The participants had to impress the audience to get selected to the next round. The winners would pair four accomplished developers (stars) and come up with a five minute coding exercise that they have to present to a panel of judges (J. B. Rainsberger, Jeff Patton). Very entertaining. Really appreciate the participants and the stars for live coding in front of a sizable audience. The winners got a life time e-learning license from Industrial Logic.

Last but not the least enjoyed speaking about Breaking the monotony with Sai Venkat. Liked the way the talk went. Agility we seek is from the code we write and systems we build and not just from processes and practices we follow. This was the theme of our talk. Got great constructive feedback from the audience.

The conference ended with an open Q and A session.

Kudos to the organizers. The slides are available and the videos should be available soon.

Looking forward to see if we can get the Dogma out of agile and build great software. Feel free to add any comments about topics that I have miss out.





Building java projects on runcoderun.com

26 01 2010

RunCodeRun is a hosted Continuous integration environment developed by Relevance. Thanks to the Relevance team and their effort to provide this service free for opensource projects.

I wanted to build rapa on RunCodeRun. I was trying to setup my project on RunCodeRun using instructions in a blog post. It is a very useful blog and easy to follow. But I was having trouble getting code to compile on runcoderun box. Here are the problems and their solutions.

I guess there is no real jdk on runcoderun, so my compile task on ant would not work.

I checked in tools.jar as a part of my project libraries. Then I added it as part of the classpath when invoking ant from rake.

classpath = [File.join(".","lib","ant.jar"), File.join(".","lib","tools.jar"), File.join(".","lib","junit.jar"), File.join(".","lib","ant-junit.jar"), File.join(".","lib","ant-launcher.jar")].join(File::PATH_SEPARATOR)
system "java -cp #{classpath} org.apache.tools.ant.Main -emacs dist"

Even after I fixed that the build would always go green even if there was failure from ant

I guess the exit status returned by rake was always zero irrespective of what ant returned. I changed the rakefile as shown below.

system "java -cp #{classpath} org.apache.tools.ant.Main -emacs dist"
exit $?.exitstatus

This seemed to fix all the issues with the build.

Along with these issues I was also facing an issue with ant-junit task with junit 4. Basically standard distribution of ant does not understand the annotations of junit4 and requires the test class to extend TestCase. I had to checkout the latest source from ant subversion trunk and build it. I am currently using these jars.

Have a look at the project in github.

http://github.com/harikrishnan83/rapa

Continuous integration on.

http://runcoderun.com/harikrishnan83/rapa





Mnesia Quickstart

5 01 2010

Basic introduction on Mnesia

Mnesia is a RDBMS. But it belongs to the nosql category of RDBMS. Reason being the query language is not sql but Erlang. That makes it very easy to store and retrieve without having to go through Object Relational Mapping. So we can actually call Mnesia an object relational database.

Why and where would one want to Mnesia?

Erlang in general is used to program highly distributed and fault tolerant systems. Even though it has its roots in the telecommunication industry, it has proven useful in several other sites like ejabbered, Facebook chat etc. Mnesia is just a part of Erlang and is built with Erlang.

Hence it gives you configurable degree of Fault-tolerance (by means of replication).

Another important feature of mnesia is the Dirty read interface. It is possible to read, write and search Mnesia tables without protecting the operation inside a transaction.

Quickstart

The below steps should get you started on mnesia, if you are using it for the first time.

Required Software – Erlang

I use ubuntu as my OS. But that should not make it much different on any other OS.

Now lets start with some code. It is useful to install the table-viewer (erlang-tv).

The goal of this exercise is to create table called person, insert few records and read them.

create a file called Person.hrl

-record(person, {name,      %% atomic, unique key
age,        %% age
married_to, %% name of partner or undefined
children }).%% list of children

create a file called Person.erl

-module(person).
-include("<path_to_person.hrl>/person.hrl").
-export([init/0]).
-export([insert/0]).
-export([read/1]).
init() ->
mnesia:create_table(person,[{attributes,record_info(fields,person)}])
.
insert() ->
T = fun() ->
X = #person{name=john,
age=36,
married_to=ana,
children=[josh,kelly,samantha]
},
mnesia:write(X)
end,
mnesia:transaction(T)
.
read(Name) ->
R = fun() ->
mnesia:read(person,Name,write)
end,
mnesia:transaction(R)

Start command line erlang. Type in the below command from the directory which contains the above two files

erl mnesia dir .

The above command conveys that the current directory will be used to store Mnesia files.

Compile the person.erl

>c(person).

{ok,person}

Start mnesia

>mnesia:start().

Create person table.

>person:init().

Insert a record.

>person:insert().

Use table viewer to check if the record has been inserted.

>tv:start().

This will launch table view application. By default the table viewer shows the ETS tables. To look at the table we just created go to view menu and select Mnesia tables.

Read the record using Mnesia:read()

>person:read(klacke).
{atomic,[{person,john,36,ana,[josh,kelly,samantha]}]}

In my next post I will cover Mnesia queries as List Comprehension.








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