Load Balancer (LB)

A Load Balancer for distributing incoming requests to a list of registered providers. Load Balancer can be configured with the following policies:

Invocation Policies:

• RandomInvocationPolicy: The Provider that is going to process the message is being selected randomly.
• RoundRobinInvocationPolicy: The Provider that is going to process the message is being selected via round-robin algorithm.

Heartbeat Policies:

• DefaultHeartbeatPolicy: Unhealthy Providers are removed from the list.
• ImprovedHeartbeatPolicy: Unhealthy Providers are removed from the list, after receiving N successful heartbeat, Provider is being added to list.

Implemented using Java 8. You can compile it via:

mvnw clean package -DskipTests

or if maven installed:

mvn clean package -DskipTests

REMARK! Unit tests include multithreaded testcases. If you enable tests, it may take a bit more time in packaging the application.

Sample Usage

...
//instantiate the load balancer
LoadBalancer loadBalancer = new LoadBalancer.Builder()
                                  .withInvocationPolicy(new RoundRobinInvocationPolicy())
                                  .withHeartbeatPolicy(new ImprovedHeartbeatPolicy())
				  .withClusterCapacity(4)
				  .withHeartbeatFrequency(10)
                                  .build();
//with no Provider   
List<Provider> providerList = new ArrayList<>();
loadBalancer.register(providerList);

//Make request to the loadbalancer,since there is no provider to process the request, a null respose will be returned.
String response = loadBalancer.get();
...
loadbalancer.shutdown();