DADA

I've tested building on various i386 and x86_64 Java/Linux platforms. You will need a recent JDK and Maven (and probably JAVA_HOME and MAVEN_HOME set).

For a demo of DADA please follow the instructions below. The demo domain is whale sightings (I am fascinated by whales), however DADA is generic enough to slice, dice and aggregate pretty much anything in realtime. At the bank at which I currently work, it is being used by Treasury to project 6 month cash trade settlement ladders and highlight late amendments.

Build DADA

git clone https://github.com/JulesGosnell/dada.git
cd dada
mvn clean install

In one shell: Start DADA Whales Demo Server

cd dada/dada-demo
../bin/clj
(load-file "src/main/clojure/org/dada/demo/whales.clj")

In another shell: Start DADA Client GUI

cd dada/dada-swt
../bin/clj
(System/exit 0)
cd ..
./bin/client

You should now be looking at DADA's MetaModel - it's Model of Models.

Click on the Whales Model.

• A View of the Whales Model should open (you can open as many as you like)
• This Model contains a live feed of whale sightings
• A whale's attributes (except type) may vary from sighting to sighting

Click on the Oceans Model.

• A View of the Oceans Model should open (you can open as many as you like)
• This Model contains a live feed of Ocean samplings
• An Ocean's attributes may vary from sample to sample

Click on the WhalesAndOceans Model.

• The WhalesAndOceans Model is derived from the Whales and Oceans Models by a query
• This query demonstrates DADA's ability to join live streams/Models in real time
• Each Whale is shown joined to its current Ocean (which may change over time)
• Whale and Ocean attribute changes are reflected in realtime in the WhalesAndOceans Model

In DADA Whales Demo Server shell/repl:

;; select namespace
(ns org.dada.demo.whales)
;; run query
(? (dunion)(dsum :weight)(dsplit :ocean)(dfrom "Whales"))

• You should see a number of new Models leap into existence in the MetaModel
• These Models are derived from the inital Whales and Oceans models via the query above
• Intermediate Models are maintained so that they may also be viewed

Click on the Whales:ocean.sum(:weight).union() Model.

• This Model maintains the ultimate result of the query that you have just entered
• The Whales have been grouped by Ocean and the weight of Whales in each of these groups summed up.
• As the weight and ocean attributes of the Whales change over time, so does this Model

Click on the Whales.split(:ocean=arctic) Model.

• This is an intermediate Model contributing to the ultimate Model above.
• It maintains the real time set of all Whales currently in the Arctic.

Click on the Whales.split(:ocean=arctic).sum(:weight) Model.

• This is a intermediate Model drawing upon another intermediate Model and contributing to the ultimate Model above.
• It represents the real time sum of the weight of all Whales currently in the Arctic.

DADA is a proof of concept, allowing me to learn about Event Stream Processing in Clojure from the inside, not (yet) production software.

Clojure is an ideal platform on which to implement ESP - A functional approach, sequence comprehension, simple concurrency, persistant containers and immutable record types.

The only serious change that I have had to make to Clojure is enabling the recording of dynamically created classes on the server and their on-demand loading into a client. This allows me to run queries server-side which create new functions and types and then to have these pulled into the running client when needed to view the resultant Models.