Software load balancer for CompletableFutures in Java, that is meant as a simple replacement for Hystrix and Ribbon when using Java 8.
It provides the following features:
- Load balancing
- Fault tolerance
- Protocol independent
Still needs to be pushed to Nexus:
<dependency>
<groupId>dk.nversion</groupId>
<artifactId>loadbalancer4java</artifactId>
<version>0.1/version>
</dependency>Create a List or Array with your endpoints, then create a new LoadBalancer with the preferred configuration:
String[] urls = new String[] { "url1", "url2", "url3" };
LoadBalancer loadBalancer = LoadBalancer.builder()
// Return indexes for 3 endpoints and do it in a round robin fashion
.setEndpointCount(urls.length)
.setPolicy(LoadBalancerPolicy.ROUND_ROBIN)
// 10 failures in 30 seconds will take the endpoint out of rotation for 60 seconds
.setMaxFailureRate(10, 30, TimeUnit.SECONDS, 60, TimeUnit.SECONDS)
// Try to call the endpoints 2 times more if the first call fails
.setRetryCount(2)
.build();Wrap the call where you call your backend with the loadBalancer and use the CompletableFuture exactly the same way as before:
// CompletableFuture<String> future = backend.call(urls[0], "request1");
CompletableFuture<String> loadBalancedFuture = loadBalancer.wrap((index, retryCount) -> {
return backend.call(urls[index], "request1");
});
loadBalancedFuture.whenComplete((response, ex) -> {
if(ex == null) {
// This is
} else {
// Handle Exception
}
});- Implement caching support like Guava CacheBuilder
- Implement queuing of calls