第十八章 dubbo-monitor计数监控

监控总体图：

红色：监控中心 - dubbo-simple-monitor

黄色：provider

蓝色：consumer

统计总体流程：

MonitorFilter向DubboMonitor发送数据
DubboMonitor将数据进行聚合后（默认聚合1min中的统计数据）暂存到ConcurrentMap<Statistics, AtomicReference<long[]>> statisticsMap，然后使用一个含有3个线程（线程名字：DubboMonitorSendTimer）的线程池每隔1min钟，调用SimpleMonitorService遍历发送statisticsMap中的统计数据，每发送完毕一个，就重置当前的Statistics的AtomicReference<long[]>
SimpleMonitorService将这些聚合数据塞入BlockingQueue<URL> queue中（队列大写为100000）
SimpleMonitorService使用一个后台线程（线程名为：DubboMonitorAsyncWriteLogThread）将queue中的数据写入文件（该线程以死循环的形式来写）
SimpleMonitorService还会使用一个含有1个线程（线程名字：DubboMonitorTimer）的线程池每隔5min钟，将文件中的统计数据画成图表

注意：

SimpleMonitorService理解为一个服务提供者；而provider和consumer都是一个服务消费者，所以二者的DubboMonitor中的MonitorService实例都是一个代理实例。
dubbo-monitor计数监控不支持异步调用下的数据监控

一、dubbo-monitor使用

在配置文件中添加：

1 <dubbo:monitor address="10.211.55.5:9090" />

即开启了monitor监控，并且指定了监控中心服务器为“10.211.55.5:9090”。

9090端口是Prometheus的默认端口，dubbo提供的监控中心比较简陋，我们后续会使用Prometheus作为监控中心来存储监控数据。

二、服务端加载monitor配置

doExportUrlsFor1Protocol(ProtocolConfig protocolConfig, List<URL> registryURLs)中：

 1             if (!Constants.SCOPE_LOCAL.toString().equalsIgnoreCase(scope)) {
 2                 ...
 3                 if (registryURLs != null && registryURLs.size() > 0) {
 4                     for (URL registryURL : registryURLs) {
 5                         ...
 6                         URL monitorUrl = loadMonitor(registryURL);
 7                         if (monitorUrl != null) {
 8                             url = url.addParameterAndEncoded(Constants.MONITOR_KEY, monitorUrl.toFullString());
 9                         }
10                        ...
11                     }
12                 } else {
13                     ...
14                 }
15             }

其中loadMonitor(URL registryURL)方法主要用于创建MonitorConfig对象（如果monitor配置在dubbo.properties中的话），并且设置属性，之后设置到数据总线Url中。

 1     protected URL loadMonitor(URL registryURL) {
 2         if (monitor == null) {
 3             String monitorAddress = ConfigUtils.getProperty("dubbo.monitor.address");
 4             String monitorProtocol = ConfigUtils.getProperty("dubbo.monitor.protocol");
 5             if ((monitorAddress == null || monitorAddress.length() == 0) && (monitorProtocol == null || monitorProtocol.length() == 0)) {
 6                 return null;
 7             }
 8 
 9             monitor = new MonitorConfig();
10             if (monitorAddress != null && monitorAddress.length() > 0) {
11                 monitor.setAddress(monitorAddress);
12             }
13             if (monitorProtocol != null && monitorProtocol.length() > 0) {
14                 monitor.setProtocol(monitorProtocol);
15             }
16         }
17         appendProperties(monitor);
18         ...
19     }

三、消费端加载monitor配置

createProxy(Map<String, String> map)中：

 1                 List<URL> us = loadRegistries(false);
 2                 if (us != null && us.size() > 0) {
 3                     for (URL u : us) {
 4                         URL monitorUrl = loadMonitor(u);
 5                         if (monitorUrl != null) {
 6                             map.put(Constants.MONITOR_KEY, URL.encode(monitorUrl.toFullString()));
 7                         }
 8                         ...
 9                     }
10                 }

四、MonitorFilter收集监控数据

consumer端在发起调用之前会先走filter链；provider端在接收到请求时也是先走filter链，然后才进行真正的业务逻辑处理。默认情况下，在consumer和provider的filter链中都会有Monitorfilter。

  1 /**
  2  * MonitorFilter. (SPI, Singleton, ThreadSafe)
  3  */
  4 @Activate(group = {Constants.PROVIDER, Constants.CONSUMER})
  5 public class MonitorFilter implements Filter {
  6 
  7     private static final Logger logger = LoggerFactory.getLogger(MonitorFilter.class);
  8 
  9     // key: 接口名.方法名 value: 当前的并发数
 10     private final ConcurrentMap<String, AtomicInteger> concurrents = new ConcurrentHashMap<String, AtomicInteger>();
 11 
 12     private MonitorFactory monitorFactory;// MonitorFactory$Adaptive
 13 
 14     public void setMonitorFactory(MonitorFactory monitorFactory) {
 15         this.monitorFactory = monitorFactory;
 16     }
 17 
 18     // intercepting invocation
 19     public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
 20         if (invoker.getUrl().hasParameter(Constants.MONITOR_KEY)) {// 开启了monitor监控
 21             RpcContext context = RpcContext.getContext(); // provider must fetch context before invoke() gets called
 22             String remoteHost = context.getRemoteHost();
 23             long start = System.currentTimeMillis(); // record start timestamp
 24             getConcurrent(invoker, invocation).incrementAndGet(); // 并发数+1
 25             try {
 26                 Result result = invoker.invoke(invocation); // proceed invocation chain
 27                 collect(invoker, invocation, result, remoteHost, start, false);// 收集统计数据
 28                 return result;
 29             } catch (RpcException e) {
 30                 collect(invoker, invocation, null, remoteHost, start, true);// 发生异常时收集统计数据
 31                 throw e;
 32             } finally {
 33                 getConcurrent(invoker, invocation).decrementAndGet(); // 并发数-1
 34             }
 35         } else {
 36             return invoker.invoke(invocation);
 37         }
 38     }
 39 
 40     // collect info
 41     private void collect(Invoker<?> invoker, Invocation invocation, Result result, String remoteHost, long start, boolean error) {
 42         try {
 43             // ---- service statistics ----
 44             long elapsed = System.currentTimeMillis() - start; // 此次调用花费的时间
 45             int concurrent = getConcurrent(invoker, invocation).get(); // current concurrent count
 46             String application = invoker.getUrl().getParameter(Constants.APPLICATION_KEY);
 47             String service = invoker.getInterface().getName(); // service name
 48             String method = RpcUtils.getMethodName(invocation); // method name
 49             URL url = invoker.getUrl().getUrlParameter(Constants.MONITOR_KEY);
 50             Monitor monitor = monitorFactory.getMonitor(url);//根据monitorUrl获取Monitor实现（默认使用DubboMonitor）
 51             if (monitor == null) {
 52                 return;
 53             }
 54             int localPort;
 55             String remoteKey;
 56             String remoteValue;
 57             if (Constants.CONSUMER_SIDE.equals(invoker.getUrl().getParameter(Constants.SIDE_KEY))) {
 58                 // ---- for service consumer ----
 59                 localPort = 0;
 60                 remoteKey = MonitorService.PROVIDER;
 61                 remoteValue = invoker.getUrl().getAddress();
 62             } else {
 63                 // ---- for service provider ----
 64                 localPort = invoker.getUrl().getPort();
 65                 remoteKey = MonitorService.CONSUMER;
 66                 remoteValue = remoteHost;
 67             }
 68             String input = "", output = "";
 69             if (invocation.getAttachment(Constants.INPUT_KEY) != null) {
 70                 input = invocation.getAttachment(Constants.INPUT_KEY);
 71             }
 72             if (result != null && result.getAttachment(Constants.OUTPUT_KEY) != null) {
 73                 output = result.getAttachment(Constants.OUTPUT_KEY);
 74             }
 75             monitor.collect(new URL(Constants.COUNT_PROTOCOL,
 76                     NetUtils.getLocalHost(), localPort,
 77                     service + "/" + method,
 78                     MonitorService.APPLICATION, application,
 79                     MonitorService.INTERFACE, service,
 80                     MonitorService.METHOD, method,
 81                     remoteKey, remoteValue,
 82                     error ? MonitorService.FAILURE : MonitorService.SUCCESS, "1",// 成功失败数
 83                     MonitorService.ELAPSED, String.valueOf(elapsed),// 调用消耗的时间
 84                     MonitorService.CONCURRENT, String.valueOf(concurrent),// 并发数
 85                     Constants.INPUT_KEY, input,
 86                     Constants.OUTPUT_KEY, output));
 87         } catch (Throwable t) {
 88             logger.error("Failed to monitor count service " + invoker.getUrl() + ", cause: " + t.getMessage(), t);
 89         }
 90     }
 91 
 92     // concurrent counter
 93     private AtomicInteger getConcurrent(Invoker<?> invoker, Invocation invocation) {
 94         String key = invoker.getInterface().getName() + "." + invocation.getMethodName();
 95         AtomicInteger concurrent = concurrents.get(key);
 96         if (concurrent == null) {
 97             concurrents.putIfAbsent(key, new AtomicInteger());
 98             concurrent = concurrents.get(key);
 99         }
100         return concurrent;
101     }
102 
103 }

调用之前，记录调用开始时间、并发数，之后进行调用，最后进行统计数据收集：

获取计算各种统计数据（调用消耗时间、调用成功/错误数等）
使用MonitorFactory获取Monitor
将统计数据构造成url
使用Monitor收集这些统计数据

获取Monitor的源码后续再说。这里获取到的是DubboMonitor实例。

五、DubboMonitor聚合监控数据

 1     private static final int LENGTH = 10;
 2     private final ConcurrentMap<Statistics, AtomicReference<long[]>> statisticsMap = new ConcurrentHashMap<Statistics, AtomicReference<long[]>>();
 3 
 4     // 聚合统计数据
 5     public void collect(URL url) {
 6         // data to collect from url
 7         int success = url.getParameter(MonitorService.SUCCESS, 0);
 8         int failure = url.getParameter(MonitorService.FAILURE, 0);
 9         int input = url.getParameter(MonitorService.INPUT, 0);
10         int output = url.getParameter(MonitorService.OUTPUT, 0);
11         int elapsed = url.getParameter(MonitorService.ELAPSED, 0);
12         int concurrent = url.getParameter(MonitorService.CONCURRENT, 0);
13         // init atomic reference
14         Statistics statistics = new Statistics(url);
15         AtomicReference<long[]> reference = statisticsMap.get(statistics);
16         if (reference == null) {
17             statisticsMap.putIfAbsent(statistics, new AtomicReference<long[]>());
18             reference = statisticsMap.get(statistics);
19         }
20         // use CompareAndSet to sum
21         long[] current;
22         long[] update = new long[LENGTH];
23         do {
24             current = reference.get();
25             if (current == null) {
26                 update[0] = success;
27                 update[1] = failure;
28                 update[2] = input;
29                 update[3] = output;
30                 update[4] = elapsed;
31                 update[5] = concurrent;
32                 update[6] = input;
33                 update[7] = output;
34                 update[8] = elapsed;
35                 update[9] = concurrent;
36             } else {
37                 update[0] = current[0] + success;
38                 update[1] = current[1] + failure;
39                 update[2] = current[2] + input;
40                 update[3] = current[3] + output;
41                 update[4] = current[4] + elapsed;
42                 update[5] = (current[5] + concurrent) / 2;
43                 update[6] = current[6] > input ? current[6] : input;
44                 update[7] = current[7] > output ? current[7] : output;
45                 update[8] = current[8] > elapsed ? current[8] : elapsed;
46                 update[9] = current[9] > concurrent ? current[9] : concurrent;
47             }
48         } while (!reference.compareAndSet(current, update));
49     }

实际上这里聚合了1min钟的统计数据到statisticsMap中。

六、Monitor使用MonitorService存储数据到队列

 1     private final ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(3, new NamedThreadFactory("DubboMonitorSendTimer", true));
 2     private final ScheduledFuture<?> sendFuture;
 3     private final long monitorInterval;
 4 
 5     public DubboMonitor(Invoker<MonitorService> monitorInvoker, MonitorService monitorService) {
 6         this.monitorInvoker = monitorInvoker;
 7         this.monitorService = monitorService;
 8         this.monitorInterval = monitorInvoker.getUrl().getPositiveParameter("interval", 60000);
 9         // collect timer for collecting statistics data
10         sendFuture = scheduledExecutorService.scheduleWithFixedDelay(new Runnable() {
11             public void run() {
12                 // collect data
13                 try {
14                     send();
15                 } catch (Throwable t) {
16                     logger.error("Unexpected error occur at send statistic, cause: " + t.getMessage(), t);
17                 }
18             }
19         }, monitorInterval, monitorInterval, TimeUnit.MILLISECONDS);
20     }

 1     public void send() {
 2         if (logger.isInfoEnabled()) {
 3             logger.info("Send statistics to monitor " + getUrl());
 4         }
 5         String timestamp = String.valueOf(System.currentTimeMillis());
 6         for (Map.Entry<Statistics, AtomicReference<long[]>> entry : statisticsMap.entrySet()) {
 7             // get statistics data
 8             Statistics statistics = entry.getKey();
 9             AtomicReference<long[]> reference = entry.getValue();
10             long[] numbers = reference.get();
11             long success = numbers[0];
12             long failure = numbers[1];
13             long input = numbers[2];
14             long output = numbers[3];
15             long elapsed = numbers[4];
16             long concurrent = numbers[5];
17             long maxInput = numbers[6];
18             long maxOutput = numbers[7];
19             long maxElapsed = numbers[8];
20             long maxConcurrent = numbers[9];
21 
22             // send statistics data
23             URL url = statistics.getUrl()
24                     .addParameters(MonitorService.TIMESTAMP, timestamp,
25                             MonitorService.SUCCESS, String.valueOf(success),
26                             MonitorService.FAILURE, String.valueOf(failure),
27                             MonitorService.INPUT, String.valueOf(input),
28                             MonitorService.OUTPUT, String.valueOf(output),
29                             MonitorService.ELAPSED, String.valueOf(elapsed),
30                             MonitorService.CONCURRENT, String.valueOf(concurrent),
31                             MonitorService.MAX_INPUT, String.valueOf(maxInput),
32                             MonitorService.MAX_OUTPUT, String.valueOf(maxOutput),
33                             MonitorService.MAX_ELAPSED, String.valueOf(maxElapsed),
34                             MonitorService.MAX_CONCURRENT, String.valueOf(maxConcurrent)
35                     );
36             monitorService.collect(url);
37 
38             // reset
39             long[] current;
40             long[] update = new long[LENGTH];
41             do {
42                 current = reference.get();
43                 if (current == null) {
44                     update[0] = 0;
45                     update[1] = 0;
46                     update[2] = 0;
47                     update[3] = 0;
48                     update[4] = 0;
49                     update[5] = 0;
50                 } else {
51                     update[0] = current[0] - success;
52                     update[1] = current[1] - failure;
53                     update[2] = current[2] - input;
54                     update[3] = current[3] - output;
55                     update[4] = current[4] - elapsed;
56                     update[5] = current[5] - concurrent;
57                 }
58             } while (!reference.compareAndSet(current, update));
59         }
60     }

首先从聚合数据存储器statisticsMap中获取相关统计数据并存储到数据总线Url中
之后调用MonitorService（这里是SimpleMonitorService），将统计数据存储到一个BlockingQueue中

注意：这里有一个改进点

由于monitorService.collect(url)是远程调用，这里在for循环体中执行远程调用，实际上是不合适的，我们可以将所有的url先暂存在一个List<URL>中，最后，使用一次monitorService.collect(urlList)即可 - 此时，可适当缩短数据发送时间。

SimpleMonitorService：

1     private final BlockingQueue<URL> queue;
2 
3     public void collect(URL statistics) {
4         queue.offer(statistics);
5         if (logger.isInfoEnabled()) {
6             logger.info("collect statistics: " + statistics);
7         }
8     }

七、MonitorService将数据写入本地文件

 1     private final ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(1, new NamedThreadFactory("DubboMonitorTimer", true));
 2     private final ScheduledFuture<?> chartFuture;
 3     private final Thread writeThread;
 4     private final BlockingQueue<URL> queue;
 5     private String statisticsDirectory = "statistics";
 6     private String chartsDirectory = "charts";
 7     private volatile boolean running = true;
 8 
 9     public SimpleMonitorService() {
10         queue = new LinkedBlockingQueue<URL>(Integer.parseInt(ConfigUtils.getProperty("dubbo.monitor.queue", "100000")));
11         writeThread = new Thread(new Runnable() {
12             public void run() {
13                 while (running) {
14                     try {
15                         write(); // write statistics
16                     } catch (Throwable t) {
17                         logger.error("Unexpected error occur at write stat log, cause: " + t.getMessage(), t);
18                         try {
19                             Thread.sleep(5000); // retry after 5 secs
20                         } catch (Throwable t2) {
21                         }
22                     }
23                 }
24             }
25         });
26         writeThread.setDaemon(true);
27         writeThread.setName("DubboMonitorAsyncWriteLogThread");
28         writeThread.start();
29         chartFuture = scheduledExecutorService.scheduleWithFixedDelay(new Runnable() {
30             public void run() {
31                 try {
32                     draw(); // draw chart
33                 } catch (Throwable t) {
34                     logger.error("Unexpected error occur at draw stat chart, cause: " + t.getMessage(), t);
35                 }
36             }
37         }, 1, 300, TimeUnit.SECONDS);
38         statisticsDirectory = ConfigUtils.getProperty("dubbo.statistics.directory");
39         chartsDirectory = ConfigUtils.getProperty("dubbo.charts.directory");
40     }

write()将统计数据写入文件，draw()将统计数据画成图片。这两种方式在实际使用中都不会用到。

最后来看一下获取Monitor实例的过程（帮助我们开发自定义的Monitor）：

1 Monitor monitor = monitorFactory.getMonitor(url);

MonitorFilter中的monitorFactory实例是：MonitorFactory$Adaptive。

 1 package com.alibaba.dubbo.monitor;
 2 
 3 import com.alibaba.dubbo.common.extension.ExtensionLoader;
 4 
 5 public class MonitorFactory$Adaptive implements com.alibaba.dubbo.monitor.MonitorFactory {
 6     public com.alibaba.dubbo.monitor.Monitor getMonitor(com.alibaba.dubbo.common.URL arg0) {
 7         if (arg0 == null) throw new IllegalArgumentException("url == null");
 8         com.alibaba.dubbo.common.URL url = arg0;
 9         String extName = (url.getProtocol() == null ? "dubbo" : url.getProtocol());
10         if (extName == null)
11             throw new IllegalStateException("Fail to get extension(com.alibaba.dubbo.monitor.MonitorFactory) name from url(" + url.toString() + ") use keys([protocol])");
12         com.alibaba.dubbo.monitor.MonitorFactory extension = (com.alibaba.dubbo.monitor.MonitorFactory) ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.monitor.MonitorFactory.class).getExtension(extName);
13         return extension.getMonitor(arg0);
14     }
15 }

首先，根据输入的url中的protocol来获取相关的MonitorFactory（这里protocol默认是dubbo，所以获取的是DubboMonitorFactory，可以通过指定dubbo:monitor标签中的protocol属性来自定义获取XxxMonitorFactory），之后调用DubboMonitorFactory.getMonitor(arg0)。该方法在其父类AbstractMonitorFactory中：

 1 /**
 2  * AbstractMonitorFactory. (SPI, Singleton, ThreadSafe)
 3  */
 4 public abstract class AbstractMonitorFactory implements MonitorFactory {
 5     private static final Logger logger = LoggerFactory.getLogger(AbstractMonitorFactory.class);
 6 
 7     // lock for getting monitor center
 8     private static final ReentrantLock LOCK = new ReentrantLock();
 9 
10     // monitor centers Map<RegistryAddress, Registry>
11     private static final Map<String, Monitor> MONITORS = new ConcurrentHashMap<String, Monitor>();
12 
13     private static final Map<String, ListenableFuture<Monitor>> FUTURES = new ConcurrentHashMap<String, ListenableFuture<Monitor>>();
14 
15     private static final ExecutorService executor = new ThreadPoolExecutor(0, 10, 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new NamedThreadFactory("DubboMonitorCreator", true));
16 
17     public static Collection<Monitor> getMonitors() {
18         return Collections.unmodifiableCollection(MONITORS.values());
19     }
20 
21     public Monitor getMonitor(URL url) {
22         url = url.setPath(MonitorService.class.getName()).addParameter(Constants.INTERFACE_KEY, MonitorService.class.getName());
23         String key = url.toServiceStringWithoutResolving();// dubbo://10.211.55.5:9090/com.alibaba.dubbo.monitor.MonitorService
24         Monitor monitor = MONITORS.get(key);
25         Future<Monitor> future = FUTURES.get(key);
26         if (monitor != null || future != null) {
27             return monitor;
28         }
29 
30         LOCK.lock();
31         try {
32             monitor = MONITORS.get(key);
33             future = FUTURES.get(key);
34             if (monitor != null || future != null) {
35                 return monitor;
36             }
37 
38             final URL monitorUrl = url;
39             // 使用另外的线程MonitorCreator来创建Monitor实例（原因是：即使Monitor创建失败，也不会影响主流程）
40             final ListenableFutureTask<Monitor> listenableFutureTask = ListenableFutureTask.create(new MonitorCreator(monitorUrl));
41             listenableFutureTask.addListener(new MonitorListener(key));
42             executor.execute(listenableFutureTask);
43             FUTURES.put(key, listenableFutureTask);
44 
45             return null;
46         } finally {
47             // unlock
48             LOCK.unlock();
49         }
50     }
51 
52     protected abstract Monitor createMonitor(URL url);
53 
54     // Callable和Runnable一样，也是创建一个线程去执行，只是Callable有返回值（T call()），而Runnable无返回值（void run()）
55     class MonitorCreator implements Callable<Monitor> {
56 
57         private URL url;
58 
59         public MonitorCreator(URL url) {
60             this.url = url;
61         }
62 
63         @Override
64         public Monitor call() throws Exception {
65             Monitor monitor = AbstractMonitorFactory.this.createMonitor(url);//调用子类的createMonitor方法创建Monitor
66             return monitor;
67         }
68     }
69 
70     class MonitorListener implements Runnable {
71 
72         private String key;
73 
74         public MonitorListener(String key) {
75             this.key = key;
76         }
77         // listenableFutureTask一旦isDone()完成（正常完成、抛出异常、被中断等），就会立即执行该方法
78         @Override
79         public void run() {
80             try {
81                 ListenableFuture<Monitor> listenableFuture = AbstractMonitorFactory.FUTURES.get(key);
82                 AbstractMonitorFactory.MONITORS.put(key, listenableFuture.get());
83                 AbstractMonitorFactory.FUTURES.remove(key);
84             } catch (InterruptedException e) {
85                 logger.warn("Thread was interrupted unexpectedly, monitor will never be got.");
86                 AbstractMonitorFactory.FUTURES.remove(key);
87             } catch (ExecutionException e) {
88                 logger.warn("Create monitor failed, monitor data will not be collected until you fix this problem. ", e);
89             }
90         }
91     }
92 }

来看DubboMonitorFactory.createMonitor(url)：

 1 /**
 2  * DefaultMonitorFactory
 3  */
 4 public class DubboMonitorFactory extends AbstractMonitorFactory {
 5 
 6     private Protocol protocol;
 7 
 8     private ProxyFactory proxyFactory;
 9 
10     public void setProtocol(Protocol protocol) {
11         this.protocol = protocol;
12     }
13 
14     public void setProxyFactory(ProxyFactory proxyFactory) {
15         this.proxyFactory = proxyFactory;
16     }
17 
18     @Override
19     protected Monitor createMonitor(URL url) {
20         url = url.setProtocol(url.getParameter(Constants.PROTOCOL_KEY, "dubbo"));
21         if (url.getPath() == null || url.getPath().length() == 0) {
22             url = url.setPath(MonitorService.class.getName());
23         }
24         String filter = url.getParameter(Constants.REFERENCE_FILTER_KEY);
25         if (filter == null || filter.length() == 0) {
26             filter = "";
27         } else {
28             filter = filter + ",";
29         }
30         url = url.addParameters(Constants.CLUSTER_KEY, "failsafe", Constants.CHECK_KEY, String.valueOf(false),
31                 Constants.REFERENCE_FILTER_KEY, filter + "-monitor");
32         // 创建Invoker<MonitorService>，内部会构造与MonitorService实现类SimpleMonitorService所在的检测中心dubbo-simple-monitor的长连接
33         Invoker<MonitorService> monitorInvoker = protocol.refer(MonitorService.class, url);
34         // 获取MonitorService的代理
35         MonitorService monitorService = proxyFactory.getProxy(monitorInvoker);
36         return new DubboMonitor(monitorInvoker, monitorService);
37     }
38 
39 }

注意：这里的SimpleMonitorService其实会部署在dubbo-simple-monitor中，被provider和consumer中的DubboMonitor调用。

posted on 2018-01-14 14:08 赵计刚阅读(14763) 评论(2) 编辑收藏举报