Solving “connection refused” issues on Debian Sid

Posted by Gabriel Falcão - 05/01/10 at 11:01:27 pm

Some weeks ago I started to experiment some network issues on my debian sid:

• The selenium-remote-control was not running:

I could even try to do a: “telnet localhost 4444″, it just did not work.

• My Apache-Solr was not capable to subscribe to apache-activemq

When reading the log, I saw:

javax.jms.JMSException: Could not connect to broker URL: tcp://localhost:61616. Reason: java.net.ConnectException: Connection refused
 at org.apache.activemq.util.JMSExceptionSupport.create(JMSExceptionSupport.java:35)
 at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:280

Could not connect to broker URL: tcp://localhost:61616. Reason: java.net.ConnectException: Connection refused

Suddenly I noticed something weird in my netstat:

tcp6       0      0 :::8983                 :::*                    LISTEN      3865/solr-globocom
tcp6       0      0 :::8161                 :::*                    LISTEN      3901/activemq-globo
tcp6       0      0 :::61616                :::*                    LISTEN      3901/activemq-globo
tcp6       0      0 127.0.0.1:41879         127.0.0.1:61616         ESTABLISHED 3865/solr-globocom
tcp6       0      0 127.0.0.1:61616         127.0.0.1:41879         ESTABLISHED 3901/activemq-globo

Everything is being bound as IPv6… humm, that doesn’t have a good smell….

Looking for solutions I’ve found this file:

/etc/sysctl.d/bindv6only.conf

interesting, huh?!?

Openning up that file, I saw a full description of it, then I just needed to change its property from this:

net.ipv6.bindv6only = 1

to this:

net.ipv6.bindv6only = 0

Well, if you have the same problem, jsut change that, restart your PC, and be happy!

New projects + agile = releases

Posted by Gabriel Falcão - 05/07/09 at 05:07:31 pm

When I lived in Belo Horizonte/MG, I used to make hack parties with some friends of mine (nothing to say about all those pizzas and beer).

The hack parties had no specific goal, but a main idea: Hack some free software, and share the knowledge.

Many of us, but specifically Lincoln and I, used to create new projects in every hack party,but only a handful of those were actually released. It was often matter for jokes like: “Oh, you are up to raise the “too many projects” exception”.

I have two words for that fact: “not agile”.

Our projects were often POCs, and we had no culture of TDD, short releases and so on.

But since I started to work at Globo.com, I learned so much about agile, specially Scrum. And some months ago I’ve just accomplished what I call as “agile feeling”.

I mean, it’s a feeling that I can deliver software with quality in a short period of time.

But how ?

The idea is quite simple, you just have to follow some principles:

Think simple

This basically means focusing at the problem at hand, never trying to solve future problems you don’t have. Most of the time the problems your foresaw will never happen, yet you spent a lot of time preparing for them.

Test before programming

Write tests for small parts of your software, they will be very modular, and you will get a trust-able software, and I can assure you that you will be 100% able to embrace the changes.

Release fully functional versions, with simple features

As human beings, we want to embrace all possibilities and solve all possible problems at once.

But this is not agile at all. Talk to your client, be pragmatic, he will like to listen the truth: “You can not ship a full-featured final version of software within the term. But you can totally ship a primary version, fully functional, with all the basic needs of the client. Keep improving the software in next releases”

I tried to summarize those thoughts, but I need blog posts for each one.

Applying those thoughts to personal projects

As I said, I have unfinished projects, and they are still unfinished, mostly because were started with a non-agile approach, and I can’t get interested to finish them.

But there are a few projects I worked in, and others I am the creator. For instance:

• Dead Parrot, a pythonic RESTFul framework django-based. Is on release 0.1-hellopolly, being used within some globo.com projects.
• Ma-Chérie, a simple filesystem-based web application to navigate through pictures. Current release: 0.1
• Sponge, a tiny web framework built on top of CherryPy and used Genshi as default template language. Sponge is the base of Ma-Chérie. Current release: 0.1
• Pyccuracy, s BDD acceptance testing tool. Heynemann started that project, as a comitter, I worked in the biggest refactoring. Current release 1.0.3-viagra
• Sleepy, is a crude, slow and rough template language, 100% based in regular expressions (which mades sleepy so slow). Actually I do not plan release it by now,  I am just having some proofs of concept of how possible is to write a template language 100% regex based, just with TDD.

All projects above, except Sleepy, were released as well, all them were developed with TDD and have  a good code coverage.

But the big deal is that, actually they will never get finished, for a simple reason. They will be in continuous development and continuous released as well.

By the way, if you want to contribute, just go to my github profile and check them out.

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