Java ServiceInstance類代碼示例

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
/**
 * Registers a monitor to receive change notices for this server set as long as this jvm process
 * is alive.  Blocks until the initial server set can be gathered and delivered to the monitor.
 * The monitor will be notified if the membership set or parameters of existing members have
 * changed.
 *
 * @param monitor the server set monitor to call back when the host set changes
 * @throws MonitorException if there is a problem monitoring the host set
 */
public void watch(final ServerSetMonitor monitor)
        throws MonitorException {
    try {
        serverSet.watch(new DynamicHostSet.HostChangeMonitor<ServiceInstance>() {
            @Override
            public void onChange(ImmutableSet<ServiceInstance> serviceInstances) {
                Set<DLSocketAddress> dlServers = Sets.newHashSet();
                for (ServiceInstance serviceInstance : serviceInstances) {
                    Endpoint endpoint = serviceInstance.getAdditionalEndpoints().get("thrift");
                    InetSocketAddress inetAddr =
                            new InetSocketAddress(endpoint.getHost(), endpoint.getPort());
                    int shardId = resolvedFromName ? -1 : serviceInstance.getShard();
                    DLSocketAddress address = new DLSocketAddress(shardId, inetAddr);
                    dlServers.add(address);
                }
                monitor.onChange(ImmutableSet.copyOf(dlServers));
            }
        });
    } catch (DynamicHostSet.MonitorException me) {
        throw new MonitorException("Failed to monitor server set : ", me);
    }
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
private ServiceInstance endpointAddressToServiceInstance(Address endpointAddress) {
    if (endpointAddress instanceof Address.Inet) {
        InetSocketAddress inetSocketAddress = ((Address.Inet) endpointAddress).addr();
        Endpoint endpoint = new Endpoint(inetSocketAddress.getHostString(), inetSocketAddress.getPort());
        HashMap<String, Endpoint> map = new HashMap<String, Endpoint>();
        map.put("thrift", endpoint);
        return new ServiceInstance(
            endpoint,
            map,
            Status.ALIVE);
    } else {
        logger.error("We expect InetSocketAddress while the resolved address {} was {}",
                    endpointAddress, endpointAddress.getClass());
        throw new UnsupportedOperationException("invalid endpoint address: " + endpointAddress);
    }
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
private LindenService.ServiceIface buildClient(String parent, String node) {
  String nodePath = FilenameUtils.separatorsToUnix(FilenameUtils.concat(parent, node));
  byte[] bytes = zkClient.readData(nodePath);
  ServiceInstance serviceInstance = JSONObject.parseObject(new String(bytes), ServiceInstance.class);
  String schema = String.format("%s:%s",
                                serviceInstance.getServiceEndpoint().getHost(),
                                serviceInstance.getServiceEndpoint().getPort());
  return Thrift.newIface(schema, LindenService.ServiceIface.class);
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
private String hostSetToString(ImmutableSet<ServiceInstance> hostSet) {
    StringBuilder result = new StringBuilder();
    result.append("(");
    for (ServiceInstance serviceInstance : hostSet) {
        Endpoint endpoint = serviceInstance.getServiceEndpoint();
        result.append(String.format(" %s:%d", endpoint.getHost(), endpoint.getPort()));
    }
    result.append(" )");

    return result.toString();
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
/**
 * Registers a monitor to receive change notices for this server set as long as this jvm process
 * is alive.  Blocks until the initial server set can be gathered and delivered to the monitor.
 * The monitor will be notified if the membership set or parameters of existing members have
 * changed.
 *
 * @param monitor the server set monitor to call back when the host set changes
 * @return A command which, when executed, will stop monitoring the host set.
 * @throws com.twitter.common.net.pool.DynamicHostSet.MonitorException if there is a problem monitoring the host set
 */
@Override
public Command watch(HostChangeMonitor<ServiceInstance> monitor) throws MonitorException {
    // First add the monitor to the watchers so that it does not miss any changes and invoke
    // the onChange method
    synchronized (watchers) {
        watchers.add(monitor);
    }

    if(resolutionPending.compareAndSet(false, false)) {
        monitor.onChange(hostSet);
    }

    return Commands.NOOP; // Return value is not used
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
@Test(timeout = 10000)
public void testInetNameResolution() throws Exception {
    String nameStr = "inet!127.0.0.1:3181";
    final CountDownLatch resolved = new CountDownLatch(1);
    final AtomicBoolean validationFailed = new AtomicBoolean(false);

    NameServerSet serverSet = new NameServerSet(nameStr);
    serverSet.watch(new DynamicHostSet.HostChangeMonitor<ServiceInstance>() {
        @Override
        public void onChange(ImmutableSet<ServiceInstance> hostSet) {
            if (hostSet.size() > 1) {
                logger.error("HostSet has more elements than expected {}", hostSet);
                validationFailed.set(true);
                resolved.countDown();
            } else if (hostSet.size() == 1) {
                ServiceInstance serviceInstance = hostSet.iterator().next();
                Endpoint endpoint = serviceInstance.getAdditionalEndpoints().get("thrift");
                InetSocketAddress address = new InetSocketAddress(endpoint.getHost(), endpoint.getPort());
                if (endpoint.getPort() != 3181) {
                    logger.error("Port does not match the expected port {}", endpoint.getPort());
                    validationFailed.set(true);
                } else if (!address.getAddress().getHostAddress().equals("127.0.0.1")) {
                    logger.error("Host address does not match the expected address {}", address.getAddress().getHostAddress());
                    validationFailed.set(true);
                }
                resolved.countDown();
            }
        }
    });

    resolved.await();
    Assert.assertEquals(false, validationFailed.get());
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
protected static ImmutableSet<ServiceInstance> readServerSet(byte[] fileContent)
    throws IOException {
  ImmutableSet.Builder<ServiceInstance> builder = new ImmutableSet.Builder<ServiceInstance>();
  InputStream stream = new ByteArrayInputStream(fileContent);
  BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
  while (true) {
    String line = reader.readLine();
    if (line == null) {
      // EOF.
      break;
    } else if (line.isEmpty()) {
      // Skip empty lines.
      continue;
    }

    // We expect each line to be of the form "hostname:port". Note that host names can
    // contain ':' themselves (e.g. ipv6 addresses).
    int index = line.lastIndexOf(':');
    Preconditions.checkArgument(index > 0 && index < line.length() - 1);

    String host = line.substring(0, index);
    int port = Integer.parseInt(line.substring(index + 1));
    builder.add(new ServiceInstance(
        new Endpoint(host, port),                 // endpoint
        Collections.<String, Endpoint>emptyMap(), // additional endpoints
        Status.ALIVE));                           // status
  }
  return builder.build();
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
private BoxedUnit respondToChanges(Addr addr) {
    ImmutableSet<ServiceInstance> oldHostSet = ImmutableSet.copyOf(hostSet);

    ImmutableSet<ServiceInstance> newHostSet = oldHostSet;

    if (addr instanceof Addr.Bound) {
        scala.collection.immutable.Set<Address> endpointAddresses = ((Addr.Bound)addr).addrs();
        scala.collection.Iterator<Address> endpointAddressesIterator = endpointAddresses.toIterator();
        HashSet<ServiceInstance> serviceInstances = new HashSet<ServiceInstance>();
        while (endpointAddressesIterator.hasNext()) {
            serviceInstances.add(endpointAddressToServiceInstance(endpointAddressesIterator.next()));
        }
        newHostSet = ImmutableSet.copyOf(serviceInstances);

    } else if (addr instanceof Addr.Failed) {
        logger.error("Name resolution failed", ((Addr.Failed)addr).cause());
        newHostSet = ImmutableSet.of();
    } else if (addr.toString().equals("Pending")) {
        logger.info("Name resolution pending");
        newHostSet = oldHostSet;
    } else if (addr.toString().equals("Neg")) {
        newHostSet = ImmutableSet.of();
    } else {
        logger.error("Invalid Addr type: {}", addr.getClass().getName());
        throw new UnsupportedOperationException("Invalid Addr type:" + addr.getClass().getName());
    }

    // Reference comparison is valid as the sets are immutable
    if (oldHostSet != newHostSet) {
        logger.info("NameServerSet updated: {} -> {}", hostSetToString(oldHostSet), hostSetToString(newHostSet));
        resolutionPending.set(false);
        hostSet = newHostSet;
        synchronized (watchers) {
            for (HostChangeMonitor<ServiceInstance> watcher: watchers) {
                watcher.onChange(newHostSet);
            }
        }

    }

    return BoxedUnit.UNIT;
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
@Override
public Command watch(final HostChangeMonitor<ServiceInstance> monitor) throws MonitorException {
  monitor(monitor);
  return null;
}
 

import com.twitter.thrift.ServiceInstance; //導入依賴的package包/類
public void initialize() throws Exception {
  // Check if use of serverset is enabled, and if so, register a change monitor so we
  // can find out how many PinLater servers are active. We use this to compute the
  // per-server rate limit.
  if (pinlaterServerSetEnabled) {
    MorePreconditions.checkNotBlank(pinlaterServerSetPath);
    LOG.info("Monitoring pinlater serverset: {}", pinlaterServerSetPath);
    String fullServerSetPath = getClass().getResource("/" + pinlaterServerSetPath).getPath();
    ServerSet serverSet = new ConfigFileServerSet(fullServerSetPath);
    serverSet.monitor(new DynamicHostSet.HostChangeMonitor<ServiceInstance>() {
      @Override
      public void onChange(ImmutableSet<ServiceInstance> hostSet) {
        int oldSize = numPinLaterServers.get();
        int newSize = hostSet.size();
        if (newSize == 0) {
          LOG.error("PinLater serverset is empty, ignoring and keeping old size: {}", oldSize);
          return;
        }
        if (oldSize == newSize) {
          LOG.info("PinLater serverset update, size unchanged: {}", oldSize);
          return;
        }

        LOG.info("PinLater serverset update, old size: {}, new size: {}", oldSize, newSize);
        numPinLaterServers.set(newSize);
        rebuild();
      }
    });
  } else {
    LOG.info("PinLater server set is disabled; rate limits will be applied per server.");
  }

  if (queueConfigFilePath == null || queueConfigFilePath.isEmpty()) {
    LOG.info("Queue config zookeeper path not specified, using defaults.");
    return;
  }

  LOG.info("Registering watch on queue config: {}", queueConfigFilePath);
  String fullQueueConfigFilePath = getClass().getResource("/" + queueConfigFilePath).getPath();
  ConfigFileWatcher.defaultInstance().addWatch(
      fullQueueConfigFilePath, new ExceptionalFunction<byte[], Void>() {
        @Override
        public Void applyE(byte[] bytes) throws Exception {
          QueueConfigSchema queueConfigSchema = QueueConfigSchema.load(bytes);
          LOG.info("Queue config update, new value: {}", queueConfigSchema);
          queueConfigSchemaRef.set(queueConfigSchema);
          rebuild();
          return null;
        }
      });
}