Java tutorial
/** * Copyright 2016 Netflix, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.netflix.hystrix.contrib.metrics.controller; import static javax.ws.rs.core.MediaType.APPLICATION_JSON; import static junit.framework.Assert.assertEquals; import static org.junit.Assert.fail; import java.io.IOException; import java.net.ServerSocket; import java.util.ArrayList; import java.util.List; import java.util.concurrent.atomic.AtomicInteger; import javax.ws.rs.Consumes; import javax.ws.rs.POST; import javax.ws.rs.Path; import javax.ws.rs.ServiceUnavailableException; import javax.ws.rs.core.Application; import javax.ws.rs.core.Response; import org.apache.commons.configuration.SystemConfiguration; import org.glassfish.jersey.media.sse.EventInput; import org.glassfish.jersey.media.sse.InboundEvent; import org.glassfish.jersey.server.ResourceConfig; import org.glassfish.jersey.test.JerseyTest; import org.glassfish.jersey.test.TestProperties; import org.junit.Assert; import org.junit.Test; import com.netflix.hystrix.HystrixCommand; import com.netflix.hystrix.HystrixCommandGroupKey; import com.netflix.hystrix.contrib.metrics.HystrixStreamFeature; /** * @author justinjose28 * */ @Path("/hystrix") public class HystricsMetricsControllerTest extends JerseyTest { protected static final AtomicInteger requestCount = new AtomicInteger(0); @POST @Path("/command") @Consumes(APPLICATION_JSON) public void command() throws Exception { TestHystrixCommand command = new TestHystrixCommand(); command.execute(); } @Override protected Application configure() { int port = 0; try { final ServerSocket socket = new ServerSocket(0); port = socket.getLocalPort(); socket.close(); } catch (IOException e1) { throw new RuntimeException("Failed to find port to start test server"); } set(TestProperties.CONTAINER_PORT, port); try { SystemConfiguration.setSystemProperties("test.properties"); } catch (Exception e) { throw new RuntimeException("Failed to load config file"); } return new ResourceConfig(HystricsMetricsControllerTest.class, HystrixStreamFeature.class); } protected String getPath() { return "hystrix.stream"; } protected boolean isStreamValid(String data) { return data.contains("\"type\":\"HystrixThreadPool\"") && data.contains("\"currentCompletedTaskCount\":" + requestCount.get()); } @Test public void testInfiniteStream() throws Exception { executeHystrixCommand(); // Execute a Hystrix command so that metrics are initialized. EventInput stream = getStream(); // Invoke Stream API which returns a steady stream output. validateStream(stream, 1000); // Validate the stream. System.out.println("Validated Stream Output 1"); executeHystrixCommand(); // Execute Hystrix Command again so that request count is updated. validateStream(stream, 1000); // Stream should show updated request count System.out.println("Validated Stream Output 2"); stream.close(); } @Test public void testConcurrency() throws Exception { executeHystrixCommand(); // Execute a Hystrix command so that metrics are initialized. List<EventInput> streamList = new ArrayList<EventInput>(); // Fire 5 requests, validate their responses and hold these connections. for (int i = 0; i < 5; i++) { EventInput stream = getStream(); System.out.println("Received Response for Request#" + (i + 1)); streamList.add(stream); validateStream(stream, 1000); System.out.println("Validated Response#" + (i + 1)); } // Sixth request should fail since max configured connection is 5. try { streamList.add(getStreamFailFast()); Assert.fail("Expected 'ServiceUnavailableException' but, request went through."); } catch (ServiceUnavailableException e) { System.out.println("Got ServiceUnavailableException as expected."); } // Close one of the connections streamList.get(0).close(); // Try again after closing one of the connections. This request should go through. EventInput eventInput = getStream(); streamList.add(eventInput); validateStream(eventInput, 1000); } private void executeHystrixCommand() throws Exception { Response response = target("hystrix/command").request().post(null); assertEquals(204, response.getStatus()); System.out.println("Hystrix Command ran successfully."); requestCount.incrementAndGet(); } private EventInput getStream() throws Exception { long timeElapsed = System.currentTimeMillis(); while (System.currentTimeMillis() - timeElapsed < 3000) { try { return getStreamFailFast(); } catch (Exception e) { } } fail("Not able to connect to Stream end point"); return null; } private EventInput getStreamFailFast() throws Exception { return target(getPath()).request().get(EventInput.class); } private void validateStream(EventInput eventInput, long waitTime) { long timeElapsed = System.currentTimeMillis(); while (!eventInput.isClosed() && System.currentTimeMillis() - timeElapsed < waitTime) { final InboundEvent inboundEvent = eventInput.read(); if (inboundEvent == null) { Assert.fail("Failed while verifying stream. Looks like connection has been closed."); break; } String data = inboundEvent.readData(String.class); System.out.println(data); if (isStreamValid(data)) { return; } } Assert.fail("Failed while verifying stream"); } public static class TestHystrixCommand extends HystrixCommand<Void> { protected TestHystrixCommand() { super(HystrixCommandGroupKey.Factory.asKey("test")); } @Override protected Void run() throws Exception { return null; } } }