Overview:

This example shows a simple pricing gateway set up that demonstrates the following:

• A trivial implementation of a gateway with command line client, backend pricing engine and asynchronous gateway listeners.

• The gateway and the pricing engine are written in Scala for its async behaviours and use OSGi declarative services as the component model.

• There is a simple blueprint persistence gateway listener written in Java that takes quotes/requests and writes them to disk

• The command line is a Java OSGi bundle

• The remote communications are pluggable via RSA but the demo will default to using SLP for discovery and EssenceRMI for the transport.

• Systems and repositories used to deploy the components on the fabric.

Source:

The source is split up into the following directories:

• gateway.api - shared Java api for components
• gateway.persistence - blueprint persistence component
• gateway.cli - simple osgi shell
• gateway.pricer - scala pricing engine using declarative services
• gateway.scripts - scripts to launch components in nimble
• gateway.system - systems to deploy components in fabric

Build:

All the dependencies are packaged with this example so just run ant from the top level gateway directory

$ cd $examples $ ant -f gateway.build/build.xml

Single JVM:

The following example shows how to setup the components so that they run in a single framework with no remote communication. First launch posh in the gateway example directory.

$ $fabric/bin/posh

Now build the repositories that nimble will use to install the artifacts

% sh gateway.scripts/repos/makeRepos.osh % sh gateway.scripts/repos/loadRepos.osh

Install the parts of the example, note that Nimble will download the dependencies from the repository.

% nim add osgi.active.bundle/gateway.cli % nim add msf/com.example.gateway id=foo % nim add msf/com.example.pricer#f type=firm % nim add msf/com.example.pricer#i type=indicative

Now use the gateway cli to connect and request some quotes

% gateway login demo % gateway request paremus ibm oracle microsoft yahoo % gateway testbatch --batchSize=10000 --batchCount=10 --requestTimeout=60000

Multi JVM:

This example launches several nimble instances and installs components in each using slp and essence rmi for the remote discovery/communication

$0 $fabric/bin/posh $1 $fabric/bin/posh $2 $fabric/bin/posh

%0 sh gateway.scripts/services/client.osh %1 sh gateway.scripts/services/impl.osh %2 sh gateway.scripts/services/pricer.osh

Now use the gateway cli to connect and request some quotes

%0 gateway testbatch --batchSize=10000 --batchCount=10 --requestTimeout=60000

Fabric:

The final example is to deploy these components via the service fabric using a system document.

First launch a number of fibres with one providing the infrastructure services.

$0 $fabric/bin/posh $1 $fabric/bin/posh -kc fibre --type=infra $n $fabric/bin/posh -kc fibre

Now connect to the infrastructure fibre and import/deploy the gateway system.

%0 fabric connect localhost:9101 %0 sh gateway.scripts/systems/gateway.osh %0 fabric status -S gateway.system

Now use the gateway cli to connect and request some quotes

%0 sh gateway.scripts/services/client.osh %0 gateway testbatch --batchSize=10000 --batchCount=10 --requestTimeout=60000