今天来说下rocketmq延迟消息内部实现 源码版本为4.6.0
# 延迟消息实现
public class DelayProducer {
public static void main(String[] args) throws MQClientException, RemotingException, InterruptedException, MQBrokerException {
DefaultMQProducer mqProducer = new DefaultMQProducer("delay-producer-group");
mqProducer.setNamesrvAddr("localhost:9876");
mqProducer.start();
String[] tags = {"A", "B", "C"};
ThreadLocalRandom current = ThreadLocalRandom.current();
Message message;
int count = 5;
for (int i = 0; i < count; i++) {
String content = "this is a delay message 当前位置: " + i;
message = new Message("delay-topic", tags[i % tags.length], content.getBytes());
message.setDelayTimeLevel(current.nextInt(5));
SendResult send = mqProducer.send(message,500000);
System.out.println("发送状态: " +send.getSendStatus() +" 消息ID: "+send.getMsgId());
}
mqProducer.sendMessageInTransaction(null,null);
mqProducer.shutdown();
}
}
#### 通过设置message的delayTimeLevel属性 来完成延迟消息发送
通过查找获取message的delayTimeLevel属性的方法对应的调用来找到对应的实现
public int getDelayTimeLevel() {
String t = this.getProperty(MessageConst.PROPERTY_DELAY_TIME_LEVEL);
if (t != null) {
return Integer.parseInt(t);
}
return 0;
}
调用如下 
发现调用主要在几个地方
- commitLog
- org.apache.rocketmq.client.impl.producer.DefaultMQProducerImpl.sendMessageInTransaction
- org.apache.rocketmq.common.message.MessageBatch.generateFromList 用户判断批量发送消息中是否存在延迟类型消息 如果存在 则报异常
- org.apache.rocketmq.store.dledger.DLedgerCommitLog#putMessage 存储所有元数据主要用于崩溃回复
因为之前了解到rocketMq整体流程 producer 发送消息给broker broker 会将消息存储到commitLog中 那我们直接去看下commitLog中的相关调用
org.apache.rocketmq.store.CommitLog#putMessage
public PutMessageResult putMessage(final MessageExtBrokerInner msg) {
// Set the storage time
msg.setStoreTimestamp(System.currentTimeMillis());
// Set the message body BODY CRC (consider the most appropriate setting
// on the client)
msg.setBodyCRC(UtilAll.crc32(msg.getBody()));
// Back to Results
AppendMessageResult result = null;
StoreStatsService storeStatsService = this.defaultMessageStore.getStoreStatsService();
String topic = msg.getTopic();
int queueId = msg.getQueueId();
final int tranType = MessageSysFlag.getTransactionValue(msg.getSysFlag());
if (tranType == MessageSysFlag.TRANSACTION_NOT_TYPE
|| tranType == MessageSysFlag.TRANSACTION_COMMIT_TYPE) {
// Delay Delivery
if (msg.getDelayTimeLevel() > 0) {
if (msg.getDelayTimeLevel() > this.defaultMessageStore.getScheduleMessageService().getMaxDelayLevel()) {
msg.setDelayTimeLevel(this.defaultMessageStore.getScheduleMessageService().getMaxDelayLevel());
}
topic = ScheduleMessageService.SCHEDULE_TOPIC;
queueId = ScheduleMessageService.delayLevel2QueueId(msg.getDelayTimeLevel());
// Backup real topic, queueId
MessageAccessor.putProperty(msg, MessageConst.PROPERTY_REAL_TOPIC, msg.getTopic());
MessageAccessor.putProperty(msg, MessageConst.PROPERTY_REAL_QUEUE_ID, String.valueOf(msg.getQueueId()));
msg.setPropertiesString(MessageDecoder.messageProperties2String(msg.getProperties()));
msg.setTopic(topic);
msg.setQueueId(queueId);
}
}
InetSocketAddress bornSocketAddress = (InetSocketAddress) msg.getBornHost();
if (bornSocketAddress.getAddress() instanceof Inet6Address) {
msg.setBornHostV6Flag();
}
InetSocketAddress storeSocketAddress = (InetSocketAddress) msg.getStoreHost();
if (storeSocketAddress.getAddress() instanceof Inet6Address) {
msg.setStoreHostAddressV6Flag();
}
long eclipsedTimeInLock = 0;
MappedFile unlockMappedFile = null;
MappedFile mappedFile = this.mappedFileQueue.getLastMappedFile();
putMessageLock.lock(); //spin or ReentrantLock ,depending on store config
try {
long beginLockTimestamp = this.defaultMessageStore.getSystemClock().now();
this.beginTimeInLock = beginLockTimestamp;
// Here settings are stored timestamp, in order to ensure an orderly
// global
msg.setStoreTimestamp(beginLockTimestamp);
if (null == mappedFile || mappedFile.isFull()) {
mappedFile = this.mappedFileQueue.getLastMappedFile(0); // Mark: NewFile may be cause noise
}
if (null == mappedFile) {
log.error("create mapped file1 error, topic: " + msg.getTopic() + " clientAddr: " + msg.getBornHostString());
beginTimeInLock = 0;
return new PutMessageResult(PutMessageStatus.CREATE_MAPEDFILE_FAILED, null);
}
result = mappedFile.appendMessage(msg, this.appendMessageCallback);
switch (result.getStatus()) {
case PUT_OK:
break;
case END_OF_FILE:
unlockMappedFile = mappedFile;
// Create a new file, re-write the message
mappedFile = this.mappedFileQueue.getLastMappedFile(0);
if (null == mappedFile) {
// XXX: warn and notify me
log.error("create mapped file2 error, topic: " + msg.getTopic() + " clientAddr: " + msg.getBornHostString());
beginTimeInLock = 0;
return new PutMessageResult(PutMessageStatus.CREATE_MAPEDFILE_FAILED, result);
}
result = mappedFile.appendMessage(msg, this.appendMessageCallback);
break;
case MESSAGE_SIZE_EXCEEDED:
case PROPERTIES_SIZE_EXCEEDED:
beginTimeInLock = 0;
return new PutMessageResult(PutMessageStatus.MESSAGE_ILLEGAL, result);
case UNKNOWN_ERROR:
beginTimeInLock = 0;
return new PutMessageResult(PutMessageStatus.UNKNOWN_ERROR, result);
default:
beginTimeInLock = 0;
return new PutMessageResult(PutMessageStatus.UNKNOWN_ERROR, result);
}
eclipsedTimeInLock = this.defaultMessageStore.getSystemClock().now() - beginLockTimestamp;
beginTimeInLock = 0;
} finally {
putMessageLock.unlock();
}
if (eclipsedTimeInLock > 500) {
log.warn("[NOTIFYME]putMessage in lock cost time(ms)={}, bodyLength={} AppendMessageResult={}", eclipsedTimeInLock, msg.getBody().length, result);
}
if (null != unlockMappedFile && this.defaultMessageStore.getMessageStoreConfig().isWarmMapedFileEnable()) {
this.defaultMessageStore.unlockMappedFile(unlockMappedFile);
}
PutMessageResult putMessageResult = new PutMessageResult(PutMessageStatus.PUT_OK, result);
// Statistics
storeStatsService.getSinglePutMessageTopicTimesTotal(msg.getTopic()).incrementAndGet();
storeStatsService.getSinglePutMessageTopicSizeTotal(topic).addAndGet(result.getWroteBytes());
handleDiskFlush(result, putMessageResult, msg);
handleHA(result, putMessageResult, msg);
return putMessageResult;
}
主要看对延迟级别判断那段
if (msg.getDelayTimeLevel() > 0) {
//延迟级别大于0
if (msg.getDelayTimeLevel() > this.defaultMessageStore.getScheduleMessageService().getMaxDelayLevel()) {
//消息设置的延迟级别大于 消息所能设置的最大延迟级别 就将消息设置为消息的最大延迟级别
msg.setDelayTimeLevel(this.defaultMessageStore.getScheduleMessageService().getMaxDelayLevel());
}
//延迟队列所属
topic = ScheduleMessageService.SCHEDULE_TOPIC;
//延迟队列Id = delayTimeLevel-1
queueId = ScheduleMessageService.delayLevel2QueueId(msg.getDelayTimeLevel());
// 备份真实的 real topic, queueId
MessageAccessor.putProperty(msg, MessageConst.PROPERTY_REAL_TOPIC, msg.getTopic());
MessageAccessor.putProperty(msg, MessageConst.PROPERTY_REAL_QUEUE_ID, String.valueOf(msg.getQueueId()));
msg.setPropertiesString(MessageDecoder.messageProperties2String(msg.getProperties()));
msg.setTopic(topic);
msg.setQueueId(queueId);
}
核心逻辑
- 修改为延迟队列topic以及对应的队列
- 备份真实的topic和队列ID 方便后续取出
后续流程 存入commitLog等待被调度
接下来看下commitLog的初始化
主要在DefaultMessageStore的构造中进行了初始化
org.apache.rocketmq.store.DefaultMessageStore#DefaultMessageStore
public DefaultMessageStore(final MessageStoreConfig messageStoreConfig, final BrokerStatsManager brokerStatsManager,
final MessageArrivingListener messageArrivingListener, final BrokerConfig brokerConfig) throws IOException {
this.messageArrivingListener = messageArrivingListener;
this.brokerConfig = brokerConfig;
this.messageStoreConfig = messageStoreConfig;
this.brokerStatsManager = brokerStatsManager;
this.allocateMappedFileService = new AllocateMappedFileService(this);
if (messageStoreConfig.isEnableDLegerCommitLog()) {
this.commitLog = new DLedgerCommitLog(this);
} else {
this.commitLog = new CommitLog(this);
}
this.consumeQueueTable = new ConcurrentHashMap<>(32);
this.flushConsumeQueueService = new FlushConsumeQueueService();
this.cleanCommitLogService = new CleanCommitLogService();
this.cleanConsumeQueueService = new CleanConsumeQueueService();
this.storeStatsService = new StoreStatsService();
this.indexService = new IndexService(this);
if (!messageStoreConfig.isEnableDLegerCommitLog()) {
this.haService = new HAService(this);
} else {
this.haService = null;
}
this.reputMessageService = new ReputMessageService();
this.scheduleMessageService = new ScheduleMessageService(this);
this.transientStorePool = new TransientStorePool(messageStoreConfig);
if (messageStoreConfig.isTransientStorePoolEnable()) {
this.transientStorePool.init();
}
this.allocateMappedFileService.start();
this.indexService.start();
this.dispatcherList = new LinkedList<>();
this.dispatcherList.addLast(new CommitLogDispatcherBuildConsumeQueue());
this.dispatcherList.addLast(new CommitLogDispatcherBuildIndex());
File file = new File(StorePathConfigHelper.getLockFile(messageStoreConfig.getStorePathRootDir()));
MappedFile.ensureDirOK(file.getParent());
lockFile = new RandomAccessFile(file, "rw");
}
而初始化DefaultMessageStore
org.apache.rocketmq.broker.BrokerController#initialize
public boolean initialize() throws CloneNotSupportedException {
boolean result = this.topicConfigManager.load();
result = result && this.consumerOffsetManager.load();
result = result && this.subscriptionGroupManager.load();
result = result && this.consumerFilterManager.load();
if (result) {
try {
this.messageStore =
new DefaultMessageStore(this.messageStoreConfig, this.brokerStatsManager, this.messageArrivingListener,
this.brokerConfig);
if (messageStoreConfig.isEnableDLegerCommitLog()) {
DLedgerRoleChangeHandler roleChangeHandler = new DLedgerRoleChangeHandler(this, (DefaultMessageStore) messageStore);
((DLedgerCommitLog) ((DefaultMessageStore) messageStore).getCommitLog()).getdLedgerServer().getdLedgerLeaderElector().addRoleChangeHandler(roleChangeHandler);
}
this.brokerStats = new BrokerStats((DefaultMessageStore) this.messageStore);
//load plugin
MessageStorePluginContext context = new MessageStorePluginContext(messageStoreConfig, brokerStatsManager, messageArrivingListener, brokerConfig);
this.messageStore = MessageStoreFactory.build(context, this.messageStore);
this.messageStore.getDispatcherList().addFirst(new CommitLogDispatcherCalcBitMap(this.brokerConfig, this.consumerFilterManager));
} catch (IOException e) {
result = false;
log.error("Failed to initialize", e);
}
}
//初始化完成 会进行调用 load
result = result && this.messageStore.load();
....
}
而BrokerController#initialize 又在BrokerStartup的createBrokerController被调用
org.apache.rocketmq.broker.BrokerStartup#createBrokerController
public static BrokerController createBrokerController(String[] args) {
//调用了initialize方法初始化
boolean initResult = controller.initialize();
if (!initResult) {
controller.shutdown();
System.exit(-3);
}
}
BrokerStartup#createBrokerController又在broker启动时调用
public class BrokerStartup {
public static Properties properties = null;
public static CommandLine commandLine = null;
public static String configFile = null;
public static InternalLogger log;
public static void main(String[] args) {
start(createBrokerController(args));
}
}
这样完成了整体一个流程
回归一下这个 BrokerController#initialize 方法会进行到调用this.messageStore.load();
而this.messageStore 已经初始化完成 实例是DefaultMessageStore
@Override
public boolean load() {
boolean result = true;
try {
boolean lastExitOK = !this.isTempFileExist();
if (null != scheduleMessageService) {
//调用存储服务的load方法
result = result && this.scheduleMessageService.load();
}
// load Commit Log
result = result && this.commitLog.load();
// load Consume Queue
result = result && this.loadConsumeQueue();
....
return result;
}
核心逻辑
- 加载scheduleMessageService.load()
- 加载commitLog.load()
DefaultMessageStore.load中会进行加载scheduleMessageService.load方法
//org.apache.rocketmq.store.schedule.ScheduleMessageService#load
@Override
public boolean load() {
//调用父类load
boolean result = super.load();
result = result && this.parseDelayLevel();
return result;
}
//org.apache.rocketmq.common.ConfigManager.load
public boolean load() {
String fileName = null;
try {
fileName = this.configFilePath();
String jsonString = MixAll.file2String(fileName);
if (null == jsonString || jsonString.length() == 0) {
return this.loadBak();
} else {
this.decode(jsonString);
log.info("load " + fileName + " OK");
return true;
}
} catch (Exception e) {
log.error("load " + fileName + " failed, and try to load backup file", e);
return this.loadBak();
}
}
public boolean parseDelayLevel() {
HashMap<String, Long> timeUnitTable = new HashMap<String, Long>();
timeUnitTable.put("s", 1000L);
timeUnitTable.put("m", 1000L * 60);
timeUnitTable.put("h", 1000L * 60 * 60);
timeUnitTable.put("d", 1000L * 60 * 60 * 24);
String levelString = this.defaultMessageStore.getMessageStoreConfig().getMessageDelayLevel();
try {
String[] levelArray = levelString.split(" ");
for (int i = 0; i < levelArray.length; i++) {
String value = levelArray[i];
String ch = value.substring(value.length() - 1);
Long tu = timeUnitTable.get(ch);
int level = i + 1;
if (level > this.maxDelayLevel) {
this.maxDelayLevel = level;
}
long num = Long.parseLong(value.substring(0, value.length() - 1));
long delayTimeMillis = tu * num;
this.delayLevelTable.put(level, delayTimeMillis);
}
} catch (Exception e) {
log.error("parseDelayLevel exception", e);
log.info("levelString String = {}", levelString);
return false;
}
return true;
}
核心逻辑
- 加载配置文件 路径为 user.home/store/config/delayOffset.json 如果文件不存在则进行加载备份文件 user.home/store/config/delayOffset.json.bak 加载失败返回false
- 解析延迟级别
正式启动流程
broker启动 org.apache.rocketmq.broker.BrokerStartup#main
public static void main(String[] args) {
start(createBrokerController(args));
}
public static BrokerController start(BrokerController controller) {
try {
controller.start();
String tip = "The broker[" + controller.getBrokerConfig().getBrokerName() + ", "
+ controller.getBrokerAddr() + "] boot success. serializeType=" + RemotingCommand.getSerializeTypeConfigInThisServer();
if (null != controller.getBrokerConfig().getNamesrvAddr()) {
tip += " and name server is " + controller.getBrokerConfig().getNamesrvAddr();
}
log.info(tip);
System.out.printf("%s%n", tip);
return controller;
} catch (Throwable e) {
e.printStackTrace();
System.exit(-1);
}
return null;
}
/**
* 启动
**/
public void start() throws Exception {
if (this.messageStore != null) {
this.messageStore.start();
}
if (this.remotingServer != null) {
this.remotingServer.start();
}
if (this.fastRemotingServer != null) {
this.fastRemotingServer.start();
}
if (this.fileWatchService != null) {
this.fileWatchService.start();
}
if (this.brokerOuterAPI != null) {
this.brokerOuterAPI.start();
}
if (this.pullRequestHoldService != null) {
this.pullRequestHoldService.start();
}
if (this.clientHousekeepingService != null) {
this.clientHousekeepingService.start();
}
if (this.filterServerManager != null) {
this.filterServerManager.start();
}
if (!messageStoreConfig.isEnableDLegerCommitLog()) {
startProcessorByHa(messageStoreConfig.getBrokerRole());
handleSlaveSynchronize(messageStoreConfig.getBrokerRole());
this.registerBrokerAll(true, false, true);
}
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
try {
BrokerController.this.registerBrokerAll(true, false, brokerConfig.isForceRegister());
} catch (Throwable e) {
log.error("registerBrokerAll Exception", e);
}
}
}, 1000 * 10, Math.max(10000, Math.min(brokerConfig.getRegisterNameServerPeriod(), 60000)), TimeUnit.MILLISECONDS);
if (this.brokerStatsManager != null) {
this.brokerStatsManager.start();
}
if (this.brokerFastFailure != null) {
this.brokerFastFailure.start();
}
}
启动过程会将多个组件进行启动 重点放在 this.messageStore.start();
org.apache.rocketmq.store.DefaultMessageStore#start
public void start() throws Exception {
lock = lockFile.getChannel().tryLock(0, 1, false);
if (lock == null || lock.isShared() || !lock.isValid()) {
throw new RuntimeException("Lock failed,MQ already started");
}
lockFile.getChannel().write(ByteBuffer.wrap("lock".getBytes()));
lockFile.getChannel().force(true);
//.....
if (!messageStoreConfig.isEnableDLegerCommitLog()) {
//应该是开启恢复模式 默认 为FALSE
this.haService.start();
//处理定时消息服务
this.handleScheduleMessageService(messageStoreConfig.getBrokerRole());
}
this.flushConsumeQueueService.start();
this.commitLog.start();
this.storeStatsService.start();
this.createTempFile();
this.addScheduleTask();
this.shutdown = false;
}
关注重点 在处理定时消息服务中
@Override
public void handleScheduleMessageService(final BrokerRole brokerRole) {
if (this.scheduleMessageService != null) {
if (brokerRole == BrokerRole.SLAVE) {
this.scheduleMessageService.shutdown();
} else {
//只有当broker角色为master时才需要启动定时消息服务
this.scheduleMessageService.start();
}
}
}
org.apache.rocketmq.store.schedule.ScheduleMessageService#start
public void start() {
if (started.compareAndSet(false, true)) {
this.timer = new Timer("ScheduleMessageTimerThread", true);
//遍历delayLevelTable
for (Map.Entry<Integer, Long> entry : this.delayLevelTable.entrySet()) {
Integer level = entry.getKey();
Long timeDelay = entry.getValue();
Long offset = this.offsetTable.get(level);
if (null == offset) {
offset = 0L;
}
if (timeDelay != null) {
//为offsetTable中的每个延迟级别的 消息创建定时任务
this.timer.schedule(new DeliverDelayedMessageTimerTask(level, offset), FIRST_DELAY_TIME);
}
}
this.timer.scheduleAtFixedRate(new TimerTask() {
@Override
public void run() {
try {
if (started.get()) {
ScheduleMessageService.this.persist();
}
} catch (Throwable e) {
log.error("scheduleAtFixedRate flush exception", e);
}
}
}, 10000, this.defaultMessageStore.getMessageStoreConfig().getFlushDelayOffsetInterval());
}
}
核心逻辑
- 遍历delayLevelTable 为每个大于0级别的延迟队列创建DeliverDelayedMessageTimerTask 负责处理定时消息
DeliverDelayedMessageTimerTask继承了TimerTask 调度具体执行run方法
org.apache.rocketmq.store.schedule.ScheduleMessageService.DeliverDelayedMessageTimerTask#run
public void run() {
try {
if (isStarted()) {
//具体执行方法
this.executeOnTimeup();
}
} catch (Exception e) {
// XXX: warn and notify me
log.error("ScheduleMessageService, executeOnTimeup exception", e);
ScheduleMessageService.this.timer.schedule(new DeliverDelayedMessageTimerTask(
this.delayLevel, this.offset), DELAY_FOR_A_PERIOD);
}
}
//org.apache.rocketmq.store.schedule.ScheduleMessageService.DeliverDelayedMessageTimerTask#executeOnTimeup
public void executeOnTimeup() {
//根据topic和queueId获取对应的消费队列
ConsumeQueue cq =
ScheduleMessageService.this.defaultMessageStore.findConsumeQueue(SCHEDULE_TOPIC,
delayLevel2QueueId(delayLevel));
long failScheduleOffset = offset;
if (cq != null) {
SelectMappedBufferResult bufferCQ = cq.getIndexBuffer(this.offset);
if (bufferCQ != null) {
try {
long nextOffset = offset;
int i = 0;
ConsumeQueueExt.CqExtUnit cqExtUnit = new ConsumeQueueExt.CqExtUnit();
for (; i < bufferCQ.getSize(); i += ConsumeQueue.CQ_STORE_UNIT_SIZE) {
long offsetPy = bufferCQ.getByteBuffer().getLong();
int sizePy = bufferCQ.getByteBuffer().getInt();
long tagsCode = bufferCQ.getByteBuffer().getLong();
if (cq.isExtAddr(tagsCode)) {
if (cq.getExt(tagsCode, cqExtUnit)) {
//存在直接获取tagsCode
tagsCode = cqExtUnit.getTagsCode();
} else {
//找不到 ext 内容。所以重新计算标签代码。
log.error("[BUG] can't find consume queue extend file content!addr={}, offsetPy={}, sizePy={}",
tagsCode, offsetPy, sizePy);
long msgStoreTime = defaultMessageStore.getCommitLog().pickupStoreTimestamp(offsetPy, sizePy);
tagsCode = computeDeliverTimestamp(delayLevel, msgStoreTime);
}
}
long now = System.currentTimeMillis();
//根据延迟级别获取应被延迟的时间
long deliverTimestamp = this.correctDeliverTimestamp(now, tagsCode);
nextOffset = offset + (i / ConsumeQueue.CQ_STORE_UNIT_SIZE);
long countdown = deliverTimestamp - now;
if (countdown <= 0) {
//当前时间大于等于应该被延迟的时间
MessageExt msgExt =
ScheduleMessageService.this.defaultMessageStore.lookMessageByOffset(
offsetPy, sizePy);
if (msgExt != null) {
try {
//重新构建投递消息 根据之前存在的真实topic和queueId重新生成一个消息并存入到commitLog中
MessageExtBrokerInner msgInner = this.messageTimeup(msgExt);
PutMessageResult putMessageResult =
ScheduleMessageService.this.writeMessageStore
.putMessage(msgInner);
if (putMessageResult != null
&& putMessageResult.getPutMessageStatus() == PutMessageStatus.PUT_OK) {
continue;
} else {
// XXX: warn and notify me
log.error(
"ScheduleMessageService, a message time up, but reput it failed, topic: {} msgId {}",
msgExt.getTopic(), msgExt.getMsgId());
ScheduleMessageService.this.timer.schedule(
new DeliverDelayedMessageTimerTask(this.delayLevel,
nextOffset), DELAY_FOR_A_PERIOD);
ScheduleMessageService.this.updateOffset(this.delayLevel,
nextOffset);
return;
}
} catch (Exception e) {
log.error(
"ScheduleMessageService, messageTimeup execute error, drop it. msgExt="
+ msgExt + ", nextOffset=" + nextOffset + ",offsetPy="
+ offsetPy + ",sizePy=" + sizePy, e);
}
}
} else {
ScheduleMessageService.this.timer.schedule(
new DeliverDelayedMessageTimerTask(this.delayLevel, nextOffset),
countdown);
ScheduleMessageService.this.updateOffset(this.delayLevel, nextOffset);
return;
}
} // end of for
nextOffset = offset + (i / ConsumeQueue.CQ_STORE_UNIT_SIZE);
ScheduleMessageService.this.timer.schedule(new DeliverDelayedMessageTimerTask(
this.delayLevel, nextOffset), DELAY_FOR_A_WHILE);
ScheduleMessageService.this.updateOffset(this.delayLevel, nextOffset);
return;
} finally {
bufferCQ.release();
}
} // end of if (bufferCQ != null)
else {
long cqMinOffset = cq.getMinOffsetInQueue();
if (offset < cqMinOffset) {
failScheduleOffset = cqMinOffset;
log.error("schedule CQ offset invalid. offset=" + offset + ", cqMinOffset="
+ cqMinOffset + ", queueId=" + cq.getQueueId());
}
}
} // end of if (cq != null)
ScheduleMessageService.this.timer.schedule(new DeliverDelayedMessageTimerTask(this.delayLevel,
failScheduleOffset), DELAY_FOR_A_WHILE);
}
private MessageExtBrokerInner messageTimeup(MessageExt msgExt) {
MessageExtBrokerInner msgInner = new MessageExtBrokerInner();
msgInner.setBody(msgExt.getBody());
msgInner.setFlag(msgExt.getFlag());
MessageAccessor.setProperties(msgInner, msgExt.getProperties());
TopicFilterType topicFilterType = MessageExt.parseTopicFilterType(msgInner.getSysFlag());
long tagsCodeValue =
MessageExtBrokerInner.tagsString2tagsCode(topicFilterType, msgInner.getTags());
msgInner.setTagsCode(tagsCodeValue);
msgInner.setPropertiesString(MessageDecoder.messageProperties2String(msgExt.getProperties()));
msgInner.setSysFlag(msgExt.getSysFlag());
msgInner.setBornTimestamp(msgExt.getBornTimestamp());
msgInner.setBornHost(msgExt.getBornHost());
msgInner.setStoreHost(msgExt.getStoreHost());
msgInner.setReconsumeTimes(msgExt.getReconsumeTimes());
msgInner.setWaitStoreMsgOK(false);
MessageAccessor.clearProperty(msgInner, MessageConst.PROPERTY_DELAY_TIME_LEVEL);
msgInner.setTopic(msgInner.getProperty(MessageConst.PROPERTY_REAL_TOPIC));
String queueIdStr = msgInner.getProperty(MessageConst.PROPERTY_REAL_QUEUE_ID);
int queueId = Integer.parseInt(queueIdStr);
msgInner.setQueueId(queueId);
return msgInner;
}
核心逻辑
- 获取到消费队列 获取消息
- 根绝tagCodes以及设置的delayTimeLevel 计算消息应被投递时间 投递时间到了 根据之前保存的真实topic和queueId进行重新构建一条消息 并存入commitLog 进入正常消费
整体梳理一下
- 通过设置delayTimeLevel 发送延迟消息
- 将消息修改为延迟消息专属的 topic 以及计算 queueId 同时将真实的消息topic和queueId还有相关message设置存下来
- 为每个不同的delayTimeLevel创建DeliverDelayedMessageTimerTask 进行处理
- 等到发送时间到达 取出消息中存储的真实topic和queueId存下来重新构建一个消息 并存入commitLog 回归到正常消费
正文结束 感谢查阅
