Getting Started¶
The best way to get to know Pravega is to start it up and run a sample Pravega application.
Running Pravega is Simple¶
Verify the following prerequisite
Java 8
Download Pravega
Download the Pravega release from the Github Releases.
If you prefer to build Pravega yourself, you can download the code and run ./gradlew distribution
. More
details are shown in the Pravega README.
$ tar xfvz pravega-<version>.tgz
Run Pravega in standalone mode
This launches all the components of Pravega on your local machine.
Note: This is for testing/demo purposes only, do not use this mode of deployment in Production!
More options and additional ways to run Pravega can be found in Running Pravega guide.
$ cd pravega-<version>
$ bin/pravega-standalone
The command above runs Pravega locally for development and testing purposes. It does not persist in the storage tiers like we do with a real deployment of Pravega and as such you shouldn't expect it to recover from crashes, and further, not rely on it for production use. For production use, we strongly encourage a full deployment of Pravega.
Running a sample Pravega Application¶
We have developed a few samples to introduce the developer to coding with Pravega here: Pravega Samples.
Download and run the "Hello World" Pravega sample reader and writer applications. Pravega dependencies will be pulled from maven central.
Note: The samples can also use a locally compiled version of Pravega. For more information, please see the README note on maven publishing.
Download the Pravega-Samples git repo
$ git clone https://github.com/pravega/pravega-samples
$ cd pravega-samples
Generate the scripts to run the applications
$ ./gradlew installDist
Run the sample "HelloWorldWriter"
This runs a simple Java application that writes a "hello world" message as an event into a Pravega stream.
$ cd pravega-samples/pravega-client-examples/build/install/pravega-client-examples
$ bin/helloWorldWriter
...
Writing message: 'hello world' with routing-key: 'helloRoutingKey' to stream 'examples / helloStream'
...
Run the sample "HelloWorldReader"
$ cd pravega-samples/pravega-client-examples/build/install/pravega-client-examples
$ bin/helloWorldReader
Example HelloWorldReader output
...
Reading all the events from examples/helloStream
...
Read event 'hello world'
No more events from examples/helloStream
...
See the README file in the pravega-client-examples for more details on running the HelloWorldReader application.