### Question:
DefaultLoadBalancer implements LoadBalancer { @Override public LoadBalancerRequestContext getRequestContext(LoadBalancerRequestConfig loadBalancerRequestConfig) { LoadBalancerRoute route = _loadBalancerContext.serverSourceFilter().getLoadBalancerRoute(loadBalancerRequestConfig); if (route == null) { LogUtil.error(_logger, "No matching route for \n" + loadBalancerRequestConfig, _loadBalancerContext.additionalInfo()); return null; } Server server = _loadBalancerContext.getLoadBalancerRule(route.getRouteId()).choose(route); return server == null ? null : new DefaultLoadBalancerRequestContext(server, _loadBalancerContext); } DefaultLoadBalancer(LoadBalancerContext loadBalancerContext); @Override LoadBalancerRequestContext getRequestContext(LoadBalancerRequestConfig loadBalancerRequestConfig); LoadBalancerContext getLoadBalancerContext();  }### Answer:
@Test @Ignore public void loadBalancerTest () { final int serverCount = 10; final int threadCount = 4; final int repeatTimes = Integer.MAX_VALUE / (serverCount * threadCount) - (serverCount * threadCount); final String lbId = Thread.currentThread().getStackTrace()[1].getMethodName(); Assert.assertTrue(serverCount * repeatTimes * threadCount > Integer.MAX_VALUE / 2); final List<Server> servers = new ArrayList<>(); for (int i = 0; i < serverCount; i++) { servers.add(new Server.Builder().setServerId("server_" + i).build()); } final HashMap<Server, AtomicInteger> dataMap = new HashMap<>(); for (Server server : servers) { dataMap.put(server, new AtomicInteger(0)); } final DefaultDynamicServerSource serverSource = new DefaultDynamicServerSource(); LoadBalancerManager factory = LoadBalancerManager.getManager("soa", TestUtils.getLoadBalancerManagerConfig()); LoadBalancerConfig config = new LoadBalancerConfig.Builder().setServerSource(serverSource).build(); final LoadBalancer loadBalancer = factory.getLoadBalancer(lbId, config); serverSource.setServers(lbId, servers); Runnable runnable = new Runnable() { @Override public void run() { for (int i = 0; i < serverCount * repeatTimes; i++) { LoadBalancerRequestContext context = loadBalancer.getRequestContext(null); dataMap.get(context.getServer()).incrementAndGet(); } } }; Thread[] threads = new Thread[threadCount]; for (int i = 0; i < threadCount; i++) { Thread thread = new Thread(runnable); thread.start(); threads[i] = thread; } Threads.wait(threads, 10); int average = threadCount * repeatTimes; int averageDelta = 10; for (int i = 0; i < serverCount; i++) { Server server = servers.get(i); int actual = dataMap.get(server).get(); System.out.println(server.toString() + " -> " + actual + ", " + average); } for (int i = 0; i < serverCount; i++) { int actual = dataMap.get(servers.get(i)).get(); Assert.assertTrue(servers.get(i).toString(), Math.abs(actual - average) < averageDelta); } }