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本文主要研究一下artemis的SlowConsumerReaperRunnable
SlowConsumerPolicy
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/settings/impl/SlowConsumerPolicy.java
public enum SlowConsumerPolicy {
KILL, NOTIFY;
public static SlowConsumerPolicy getType(int type) {
switch (type) {
case 0:
return KILL;
case 1:
return NOTIFY;
default:
return null;
}
}
}
- SlowConsumerPolicy定义了KILL、NOTIFY两个枚举值
SlowConsumerReaperRunnable
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/QueueImpl.java
private final class SlowConsumerReaperRunnable implements Runnable {
private final SlowConsumerPolicy policy;
private final float threshold;
private final long checkPeriod;
private SlowConsumerReaperRunnable(long checkPeriod, float threshold, SlowConsumerPolicy policy) {
this.checkPeriod = checkPeriod;
this.policy = policy;
this.threshold = threshold;
}
@Override
public void run() {
float queueRate = getRate();
long queueMessages = getMessageCount();
if (logger.isDebugEnabled()) {
logger.debug(getAddress() + ":" + getName() + " has " + queueMessages + " message(s) and " + getConsumerCount() + " consumer(s) and is receiving messages at a rate of " + queueRate + " msgs/second.");
}
if (consumers.size() == 0) {
logger.debug("There are no consumers, no need to check slow consumer's rate");
return;
} else {
float queueThreshold = threshold * consumers.size();
if (queueRate < queueThreshold && queueMessages < queueThreshold) {
if (logger.isDebugEnabled()) {
logger.debug("Insufficient messages received on queue \"" + getName() + "\" to satisfy slow-consumer-threshold. Skipping inspection of consumer.");
}
return;
}
}
for (ConsumerHolder consumerHolder : consumers) {
Consumer consumer = consumerHolder.consumer();
if (consumer instanceof ServerConsumerImpl) {
ServerConsumerImpl serverConsumer = (ServerConsumerImpl) consumer;
float consumerRate = serverConsumer.getRate();
if (consumerRate < threshold) {
RemotingConnection connection = null;
ActiveMQServer server = ((PostOfficeImpl) postOffice).getServer();
RemotingService remotingService = server.getRemotingService();
for (RemotingConnection potentialConnection : remotingService.getConnections()) {
if (potentialConnection.getID().toString().equals(serverConsumer.getConnectionID())) {
connection = potentialConnection;
}
}
serverConsumer.fireSlowConsumer();
if (connection != null) {
ActiveMQServerLogger.LOGGER.slowConsumerDetected(serverConsumer.getSessionID(), serverConsumer.getID(), getName().toString(), connection.getRemoteAddress(), threshold, consumerRate);
if (policy.equals(SlowConsumerPolicy.KILL)) {
connection.killMessage(server.getNodeID());
remotingService.removeConnection(connection.getID());
connection.fail(ActiveMQMessageBundle.BUNDLE.connectionsClosedByManagement(connection.getRemoteAddress()));
} else if (policy.equals(SlowConsumerPolicy.NOTIFY)) {
TypedProperties props = new TypedProperties();
props.putIntProperty(ManagementHelper.HDR_CONSUMER_COUNT, getConsumerCount());
props.putSimpleStringProperty(ManagementHelper.HDR_ADDRESS, address);
props.putSimpleStringProperty(ManagementHelper.HDR_REMOTE_ADDRESS, SimpleString.toSimpleString(connection.getRemoteAddress()));
if (connection.getID() != null) {
props.putSimpleStringProperty(ManagementHelper.HDR_CONNECTION_NAME, SimpleString.toSimpleString(connection.getID().toString()));
}
props.putLongProperty(ManagementHelper.HDR_CONSUMER_NAME, serverConsumer.getID());
props.putSimpleStringProperty(ManagementHelper.HDR_SESSION_NAME, SimpleString.toSimpleString(serverConsumer.getSessionID()));
Notification notification = new Notification(null, CoreNotificationType.CONSUMER_SLOW, props);
ManagementService managementService = ((PostOfficeImpl) postOffice).getServer().getManagementService();
try {
managementService.sendNotification(notification);
} catch (Exception e) {
ActiveMQServerLogger.LOGGER.failedToSendSlowConsumerNotification(notification, e);
}
}
}
}
}
}
}
}
- SlowConsumerReaperRunnable实现了Runnable接口，其run方法会遍历consumers，对于ServerConsumerImply在其consumerRate小于threshold时执行serverConsumer.fireSlowConsumer()；之后对于connection不为null的根据policy进行不同的处理，若为SlowConsumerPolicy.KILL则执行connection.killMessage(server.getNodeID())、connection.fail(ActiveMQMessageBundle.BUNDLE.connectionsClosedByManagement(connection.getRemoteAddress()))，若为SlowConsumerPolicy.NOTIFY则构建NotificationType为CoreNotificationType.CONSUMER_SLOW的notification执行managementService.sendNotification(notification)
fireSlowConsumer
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/ServerConsumerImpl.java
public class ServerConsumerImpl implements ServerConsumer, ReadyListener {
//......
public void fireSlowConsumer() {
if (slowConsumerListener != null) {
slowConsumerListener.onSlowConsumer(this);
}
}
//......
}
- fireSlowConsumer执行的是slowConsumerListener.onSlowConsumer(this)方法
SlowConsumerDetection
activemq-artemis-2.11.0/artemis-protocols/artemis-openwire-protocol/src/main/java/org/apache/activemq/artemis/core/protocol/openwire/OpenWireConnection.java
class SlowConsumerDetection implements SlowConsumerDetectionListener {
@Override
public void onSlowConsumer(ServerConsumer consumer) {
if (consumer.getProtocolData() != null && consumer.getProtocolData() instanceof AMQConsumer) {
AMQConsumer amqConsumer = (AMQConsumer) consumer.getProtocolData();
ActiveMQTopic topic = AdvisorySupport.getSlowConsumerAdvisoryTopic(amqConsumer.getOpenwireDestination());
ActiveMQMessage advisoryMessage = new ActiveMQMessage();
try {
advisoryMessage.setStringProperty(AdvisorySupport.MSG_PROPERTY_CONSUMER_ID, amqConsumer.getId().toString());
protocolManager.fireAdvisory(context, topic, advisoryMessage, amqConsumer.getId(), null);
} catch (Exception e) {
ActiveMQServerLogger.LOGGER.warn("Error during method invocation", e);
}
}
}
}
- SlowConsumerDetection实现了SlowConsumerDetectionListener接口，其onSlowConsumer方法执行的是protocolManager.fireAdvisory方法
RemotingConnectionImpl
activemq-artemis-2.11.0/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/protocol/core/impl/RemotingConnectionImpl.java
public class RemotingConnectionImpl extends AbstractRemotingConnection implements CoreRemotingConnection {
//......
public void killMessage(SimpleString nodeID) {
if (channelVersion < DisconnectConsumerWithKillMessage.VERSION_INTRODUCED) {
return;
}
Channel clientChannel = getChannel(1, -1);
DisconnectConsumerWithKillMessage response = new DisconnectConsumerWithKillMessage(nodeID);
clientChannel.send(response, -1);
}
public void fail(final ActiveMQException me, String scaleDownTargetNodeID) {
synchronized (failLock) {
if (destroyed) {
return;
}
destroyed = true;
}
if (!(me instanceof ActiveMQRemoteDisconnectException)) {
ActiveMQClientLogger.LOGGER.connectionFailureDetected(transportConnection.getRemoteAddress(), me.getMessage(), me.getType());
}
try {
transportConnection.forceClose();
} catch (Throwable e) {
ActiveMQClientLogger.LOGGER.failedForceClose(e);
}
// Then call the listeners
callFailureListeners(me, scaleDownTargetNodeID);
callClosingListeners();
internalClose();
for (Channel channel : channels.values()) {
channel.returnBlocking(me);
}
}
//......
}
- killMessage方法构造DisconnectConsumerWithKillMessage并通过clientChannel.send方法；fail方法则执行transportConnection.forceClose()、callFailureListeners、callClosingListeners、internalClose以及channel.returnBlocking方法
sendNotification
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/management/impl/ManagementServiceImpl.java
public class ManagementServiceImpl implements ManagementService {
//......
public void sendNotification(final Notification notification) throws Exception {
if (logger.isTraceEnabled()) {
logger.trace("Sending Notification = " + notification +
", notificationEnabled=" + notificationsEnabled +
" messagingServerControl=" + messagingServerControl);
}
// This needs to be synchronized since we need to ensure notifications are processed in strict sequence
synchronized (this) {
if (messagingServerControl != null && notificationsEnabled) {
// We also need to synchronize on the post office notification lock
// otherwise we can get notifications arriving in wrong order / missing
// if a notification occurs at same time as sendQueueInfoToQueue is processed
synchronized (postOffice.getNotificationLock()) {
// First send to any local listeners
for (NotificationListener listener : listeners) {
try {
listener.onNotification(notification);
} catch (Exception e) {
// Exception thrown from one listener should not stop execution of others
ActiveMQServerLogger.LOGGER.errorCallingNotifListener(e);
}
}
// start sending notification *messages* only when server has initialised
// Note at backup initialisation we don't want to send notifications either
// https://jira.jboss.org/jira/browse/HORNETQ-317
if (messagingServer == null || !messagingServer.isActive()) {
if (logger.isDebugEnabled()) {
logger.debug("ignoring message " + notification + " as the server is not initialized");
}
return;
}
long messageID = storageManager.generateID();
Message notificationMessage = new CoreMessage(messageID, 512);
// Notification messages are always durable so the user can choose whether to add a durable queue to
// consume them in
notificationMessage.setDurable(true);
notificationMessage.setAddress(managementNotificationAddress);
if (notification.getProperties() != null) {
TypedProperties props = notification.getProperties();
props.forEach(notificationMessage::putObjectProperty);
}
notificationMessage.putStringProperty(ManagementHelper.HDR_NOTIFICATION_TYPE, new SimpleString(notification.getType().toString()));
notificationMessage.putLongProperty(ManagementHelper.HDR_NOTIFICATION_TIMESTAMP, System.currentTimeMillis());
if (notification.getUID() != null) {
notificationMessage.putStringProperty(new SimpleString("foobar"), new SimpleString(notification.getUID()));
}
postOffice.route(notificationMessage, false);
}
}
}
}
//......
}
- sendNotification方法会回调listeners的onNotification方法，之后通过postOffice.route(notificationMessage, false)发送notificationMessage
小结
SlowConsumerReaperRunnable实现了Runnable接口，其run方法会遍历consumers，对于ServerConsumerImply在其consumerRate小于threshold时执行serverConsumer.fireSlowConsumer()；之后对于connection不为null的根据policy进行不同的处理，若为SlowConsumerPolicy.KILL则执行connection.killMessage(server.getNodeID())、connection.fail(ActiveMQMessageBundle.BUNDLE.connectionsClosedByManagement(connection.getRemoteAddress()))，若为SlowConsumerPolicy.NOTIFY则构建NotificationType为CoreNotificationType.CONSUMER_SLOW的notification执行managementService.sendNotification(notification)
doc
来源：oschina
链接：https://my.oschina.net/go4it/blog/3161394