Overview

Architecture
Actor Overview
Technologies
Roadmap
History

Getting started

Prerequisites
Download
Hello World
Hello World with Kafka
Examples

Documentation

Actor Reference
API Reference
The event log
Handling and forwarding
State calculation
Scaling out
Command line parameters
Configuration Reference





























Prerequisites

The following prerequisites exist to run Coral:

  • API knowledge
    Basic knowledge of RESTful interfaces and JSON. Coral is controlled through a RESTful HTTP interface. At this moment, there is no visual interface yet, so the application can only be controlled through its HTTP API.
  • Cassandra
    A running Cassandra instance. To download the latest version of Cassandra, visit http://cassandra.apache.org.
  • Kafka
    A running Kafka instance. To download the latest version of Kafka, visit the website.
  • Spark
    A running Spark instance is needed if you want to use Spark for state calculation. To download the latest version of Spark, visit http://spark.apache.org.
  • ElasticSearch
    A running instance of ElasticSearch is needed if you want to search JSON events from the event log. To download the latest version of ElasticSearch, visit https://www.elastic.co.
  • HTTP client
    An HTTP client. There are a lot of different ways to issue commands to Coral, all of which use HTTP. A convenient way to send API calls to Coral is with Postman, a browser plugin for Google Chrome. It is also possible to use curl, a bash command line tool, to enter the commands. It is also possible to write a Python script to enter the commands. A python or bash script has the advantage that combinations of commands can be stored and later executed. So pick your favorite HTTP client!

We have not tested Coral against old versions of these tools, for this reason it is recommended to download the latest version of these programs.

If you are compiling from source and you want to obtain the latest version from GitHub, the following additional prerequisites exist:

  • Git
    To obtain the latest version of the repository from GitHub, download Git here. It might already be installed on your machine, however. To find out, type git --version in a command prompt.
  • Scala
    Scala 2.11.6. To download Scala, visit the Scala website. It may already be preinstalled on your machine. To find out, type scala -version. We have not tested compiling and running Coral with earlier versions of Scala. For this reason, the latest version is recommended.
  • Maven
    Coral uses Maven as its build system. It might already be installed on your machine. To find out, type mvn --version in a command prompt. If not installed, download it here.