Word Dictionary

This word dictionary service is built by Scala, Akka Http and Cassandra,etc.

The architecture is designed to provide large volume storage capability and low response latency.

• Scala is a type-safe high-level programming language combining both OOP and functional style. It's a perfect language to handle concurrent and parallel data processing.

• Akka Http is an Actor-based toolkit for interacting with web services and clients built on Akka Streams. It can handle large throughput in sub-second response latency.

• Cassandra is Peer-to-Peer distributed Key-value store, which has outstanding read/write preformance.

Prerequisites

• Install Cassandra

Download Cassadra from:

http://httpd-mirror.frgl.pw/apache/cassandra/3.0.11/apache-cassandra-3.0.11-bin.tar.gz

Unzip it to your local and start Cassandra service

$ ./pathToCassandra/bin/cassandra

• Install Java 8, Scala and sbt

Please follow my blog:

http://alvincjin.blogspot.ca/2017/01/install-java-and-scala-in-ubuntu.html

• Build the executable jar

$ sbt assembly

The jar file is packaged to ~/dictionary/target/scala-2.11/dictionary-1.0.0.jar

Execution

• Start the dictionary service

java -Dconfig.file=application.conf -classpath dictionary-1.0.0.jar com.alvin.dict.ServiceBootStrap

API Examples

To test the APIs, you can use either Google Postman or curl.

• Create an entry in the dictionary

POST localhost:8080/entry

Body:
{
	"word":"azz",
	"description":"zza is test"
}

• Retrieve entries with word starting with a specific prefix

GET localhost:8080/description/az

Response:
[
  {
    "word": "azza",
    "description": "azza is test"
  },
  {
    "word": "azz",
    "description": "azz is also a test"
  }
]

• Retrieve the description of a given word

GET localhost:8080/entry/azz

Response:
{
  "word": "azz",
   "description": "azz is also a test"
}

• Delete an entry by word

DELETE localhost:8080/entry/azz

Response:
Deleted azz Successfully

• Count total entries in the dictionary

GET localhost:8080/count

Response:
2