Table of contents

Streams Domain and Instance

To run your application in distributed mode, you need a Streams Domain and a Streams Instance. A domain is a logical grouping of resources (or containers) in a network for common management and administration. It can contain one or more instances that share a security model, and a set of domain services. An instance is the Streams distributed runtime environment. It is composed of a set of interacting services running across one or multiple resources. The Streams Instance is responsible for running Streams applications. When an application is submitted onto a Streams instance, it distributes the application code onto each of the resources. It coordinates with the instance services to execute the processing elements.

Setting up a Development Domain and Instance

To set up a development domain and instance, follow these steps. A development domain and instance runs on a single host. You can dynamically add additional host to the domain later. First, if you have not already done so, set up the necessary environment variables by running the streamsprofile.sh. 
    source  <Streams_Install>/bin/streamsprofile.sh
Next, start streamstool by typing the following command: 
    streamtool
When prompted to provide a ZooKeeper ensemble, enter the ZooKeeper ensemble string if you have a ZooKeeper server set up. Otherwise, press enter to use the embedded ZooKeeper. streamtool is an interactive tool. To get content assist and auto-complete, press <Tab>.

Domain

To make a new domain, enter this command in the streamtool interactive command session: 
    mkdomain -d <domainName>
Generate public and private key for Streams, so you do not have to keep logging in: 
    genkey
Start the domain: 
    startdomain
Tip: If the domain fails to start because a port is in use, you may change the port number by using setdomainproperty. For example, if JMX and SWS ports are in use: 
    setdomainproperty jmx.port=<jmxPort> sws.port=<sws.Port>

Instance

To make a new instance, enter this command: 
    mkinstance -i <instance-id>
Start the instance: 
    startinstance

Running Streams Applications in Distributed Mode

Now that you have a domain and instance started, you can run your application in distributed mode. To submit a job, find the application bundle file (*.sab), and run the following command: 
    streamtool submitjob appBundleName.sab
To submit our sample application, we will change into the output directory of the application and submit the application bundle: 
    cd output/application.TradesAppMain/
    streamtool submitjob application.TradesAppMain.sab

Querying for Job Status

You may query job status from your Streams Instance using streamtool commands. If using embedded ZooKeeper: 
    streamtool lsjob -d <streamsDomainName> -i <instanceName> --embeddedzk
If using external ZooKeeper ensemble: 
    streamtool lsjob -d <streamsDomainName> -i <instanceName> --zkconnect <zooKeeperHost>:<zooKeeperPort>
You will see job status similar to this: 
    [streamsadmin@streamsqse Distributed]$ streamtool lsjobs -d StreamsDomain -i StreamsInstance --embeddedzk
    Instance: StreamsInstance
    Id State Healthy User Date Name Group
    6 Running yes streamsadmin 2015-04-30T18:32:48-0400 application::TradesAppMain_6 default