url-shortening

Overview

url-shortening is a micro-service solution that allows storing short urls

Architecture

Micro-services:

• api-service − service to create short urls and redirect by them
• id-service − service to identify api-services if multiple of them have been started
• hazelcast-service − IMDG service (aka cache) to store and retrieve urls
• config-service − service to store all service configs
• eureka-service − service discovery
• zuul-service − entry-point service with LB

Storage:

• Hazelcast − IMDG solution included into hazelcast-service. Can be distributed, so all solution can be scaled easily

TODO: add picture

API

If you run solution at localhost with default properties then entry-point url will be localhost:8090 All communication between services and API is REST

• Request:

  GET /as/<shortUrl>
  

  Response:

  302 Found 
  Location: <long_url>
  

• Request:

  POST /as 
  {
      "url" : "<long_url_here>""
  }
  

  Response:

  200 OK 
  <shortUrl>
  

Build and start

Requirements

• java >= 1.8 (make sure java is added to $PATH environment)
• docker + docker-compose (optional: for convenient start only)

Building

Run the following command from the project root:

./gradlew cleand build

Starting

To start any service go the according folder (e.g. api-service)

cd api-service/build/libs

and run

java -jar api-service.jar

To run multiple instances of service you should change the start-up port:

java -jar api-service.jar --server.port=[port]

Building docker images

Build the whole project as described in build section and then run the following command:

docker-compose build

Starting docker-compose

Project has docker-compose.yml for example with the following service configuration:

• eureka-service - 1 instance
• config-service - 1 instance
• zuul-service - 1 instance
• hazelcast-service - 3 instances
• id-service - 1 instance
• api-service - 2 instances

As for now there is no dependencies between services they should be started in the order they mentioned above. So the start will look like:

docker-compose -d up eureka-service
docker-compose -d up config-service
docker-compose -d up zuul-service
docker-compose -d up hazelcast-service-1 hazelcast-service-2 hazelcast-service-3
docker-compose -d up id-service
docker-compose -d up api-service-1 api-service-2

Request API stays the same

Load testing

For simple load testing ab utility can be used:

ab -p ./post.json -T application/json -n 100000 -c 4 -k http://localhost:8090/as

where post.json file contains request body. Read request:

ab -n 100000 -c 4 -k http://localhost:8090/as/<short_url>

where <short_url> − one of short urls generated at previous step

Further possible improvements

Strict improvements:

• Data storage under Hazelcast
• id-service must free IDs not in use
• Run services with tune memory
• Start up of some service must depend on other ones

Optional improvements:

• Integration tests
• Docker build images via Gradle task
• Separate read and write operations into two services
• Set expiration time for urls
• Add DeveloperConsole service
• Spring-boot-starters for common configs