I submitted a patch to the Netty project for supporting the Web Sockets protocol.

To demonstrate how to use this patch, I’ve created a little demo. This demo consists of a simple web page for sending data to the server using the Web Sockets API JavaScript API, and a simple Netty server for serving up the web page and handling the data send over the Web Socket protocol. You can download this demo from, http://people.apache.org/~mheath/websocketexample.zip. To compile it, you will need that latest version of Netty from Subversion and apply the patch I mentioned earlier.

When I ran my my original comparison, both the tests and databases were running on the same host connecting over the loopback interface. Using the loopback interface is a good way to test but the performance characteristics of going over a real network are much different. So I ran the tests again connecting to a second host over a gigabit/second Ethernet network.

I’ve also updated my tests to use the latest versions of both MINA and Netty.

Not only did I run the tests again over a real network connection, but I also added results for using Postgresql as well as the results of using plain JDBC and using JDBC with a thread-pool. Each test executes 50 SELECT statements and each test was run 100 times. Very interesting results.

An astute observer would question why JDBC is so much slower than both ADBCJ/MINA or ADBCJ/Netty. The answer to that question is the fact that ADBCJ supports pipelining which increases the performance of executing multiple queries significantly.

Netty continues to amaze and MINA is still really slow. It’s unfortunate to see the slow progress of MINA. While MINA 2.0 still hasn’t been released, Netty releases happen on a regular basis. It’s true that I’m on the MINA PMC and I could help get a 2.0 release out the door but I just don’t have the time. And honestly, why would I want to contribute to MINA when Netty is making faster progress and is frankly a better framework?

If you’re interested in participating, please let us know.

Netty is much more clever than MINA. In Netty, when you make a call to send data and the send queue is empty, Netty will just send the data. We are using non-blocking I/O so the call will still be asynchronous. If the send queue is not empty, Netty will queue up the data to be sent in much the same way that MINA does sends. The Netty approach is much faster.

Using ADBCJ I conducted a simple performance test comparing MINA and Netty. The test runs 100 simple select SQL queries against MySQL that each return a single string. Each test was run 100,000 times.

As you can see, Netty is significantly faster. In all the tests I’ve run so far, Netty has been faster.

To say I’m please with Netty would be an understatement.

This talk really puts into perspective the importance of things like distributed hash tables and other peer-to-peer technologies and shows that there’s more use for these technologies than just pirating software.

openssl s_client -connect google.com:443

Google’s server will send back some information about your secure connection at which point you can type:

GET / HTTP/1.1Host: www.google.com

(don’t forget an extra carriage return after the last line) and happily watch Google redirect you to a normal HTTP URL.openssl s_client will also let you do STARTTLS with SMTP. I wish I would have known about that when I was building my SMTP server on MINA. I implemented STARTTLS for it and and was an absolute pain to test and debug. Using openssl would have made my life much easier.

Dear Applicant,

First of all, Google and the open source organizations taking part in
Google Summer of Code would like to thank for applying to take part in
the program this year. Unfortunately, your application was not one of
those selected to take part in the program. Universally, the quality
of the submitted applications was very high, but we had a limited
number of slots available. This often difficult decision was made by
the organization you applied to, so any questions regarding
application selection should be directed at them.

We hope you'll consider applying next year.

Kind regards,
The Google Summer of Code Program Administration Team

The $4,500 stipend would have gone a long way towards a MacBook Pro and other fun toys. Oh well. I’ll just have to remain content with my employer issued Dell.

The good news is that I won’t have anything distracting me from getting my thesis done. If you can call that good news…

git svn clone --stdlayout https://svn.apache.org/repos/asf/mina/asyncweb

Git would output:

Initialized empty Git repository in .git/
Using higher level of URL: https://svn.apache.org/repos/asf/mina/asyncweb => https://svn.apache.org/repos/asf
W: Ignoring error from SVN, path probably does not exist: (175002): RA layer request failed: REPORT request failed on '/repos/asf/!svn/bc/100': REPORT of '/repos/asf/!svn/bc/100': Could not read chunk size: Secure connection truncated (https://svn.apache.org)
W: Do not be alarmed at the above message git-svn is just searching aggressively for old history.
This may take a while on large repositories

It would churn for a LONG while and finally die spewing out:

RA layer request failed: REPORT request failed on '/repos/asf/!svn/vcc/default': REPORT of '/repos/asf/!svn/vcc/default': 400 Bad Request (https://svn.apache.org) at /usr/bin/git-svn line 3813

I Googled for a solution, of course, and didn’t find anything. Git would create a project folder but it didn’t have anything in it except for the .git directory. I tried doing a ‘git svn rebase’ and it would fail. Out of desperation I tried doing ‘git svn fetch’ and voila! Git started pulling down the project and its history. It still takes a painfully long time to find the project’s history and fetch it but the flexibility and dynamics of Git make the required patience worth it.