RocketMQ源码 Broker-SubscriptionGroupManager 订阅组管理组件源码分析

前言

SubscriptionGroupManager 继承了ConfigManager配置管理组件，拥有将内存数据持久化到磁盘文件subscriptionGroup.json的能力。它主要负责维护所有消费组在内存中的订阅数据。

源码版本：4.9.3

源码架构图

核心数据结构

主要的数据结构比较简单，维护了Map<消费组名称, 订阅组配置>的映射关系。

// 订阅组管理组件
public class SubscriptionGroupManager extends ConfigManager {private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.BROKER_LOGGER_NAME);// Map<消费组名称，订阅组配置>private final ConcurrentMap<String, SubscriptionGroupConfig> subscriptionGroupTable =new ConcurrentHashMap<String, SubscriptionGroupConfig>(1024);// 内存数据版本号private final DataVersion dataVersion = new DataVersion();
}

深入看下SubscriptionGroupConfig 的数据结构。

public class SubscriptionGroupConfig {// 消费组名称private String groupName;// 是否开启消费private boolean consumeEnable = true;// 是否允许消费最早消息private boolean consumeFromMinEnable = true;// 是否允许广播消费private boolean consumeBroadcastEnable = true;// 重试队列数private int retryQueueNums = 1;// 重试最大次数private int retryMaxTimes = 16;// brokerIdprivate long brokerId = MixAll.MASTER_ID;// 当产生慢消费时，选择第几个brokerprivate long whichBrokerWhenConsumeSlowly = 1;// 是否通知消费者ids变化private boolean notifyConsumerIdsChangedEnable = true;
}

核心数据行为

数据行为主要都是对上面提到的数据结构的维护，代码 + 注释如下：

// 订阅组管理组件
public class SubscriptionGroupManager extends ConfigManager {public SubscriptionGroupManager() {this.init();}public SubscriptionGroupManager(BrokerController brokerController) {this.brokerController = brokerController;this.init();}private void init() {{// 初始化系统消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.TOOLS_CONSUMER_GROUP);this.subscriptionGroupTable.put(MixAll.TOOLS_CONSUMER_GROUP, subscriptionGroupConfig);}{// 初始化过滤服务消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.FILTERSRV_CONSUMER_GROUP);this.subscriptionGroupTable.put(MixAll.FILTERSRV_CONSUMER_GROUP, subscriptionGroupConfig);}{// 初始化自测消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.SELF_TEST_CONSUMER_GROUP);this.subscriptionGroupTable.put(MixAll.SELF_TEST_CONSUMER_GROUP, subscriptionGroupConfig);}{// 初始化http代理消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.ONS_HTTP_PROXY_GROUP);subscriptionGroupConfig.setConsumeBroadcastEnable(true);this.subscriptionGroupTable.put(MixAll.ONS_HTTP_PROXY_GROUP, subscriptionGroupConfig);}{// 初始化ONS_API_PULL消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.CID_ONSAPI_PULL_GROUP);subscriptionGroupConfig.setConsumeBroadcastEnable(true); // 激活广播模式this.subscriptionGroupTable.put(MixAll.CID_ONSAPI_PULL_GROUP, subscriptionGroupConfig);}{// 初始化ONS_API_PERMISSION消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.CID_ONSAPI_PERMISSION_GROUP);subscriptionGroupConfig.setConsumeBroadcastEnable(true);this.subscriptionGroupTable.put(MixAll.CID_ONSAPI_PERMISSION_GROUP, subscriptionGroupConfig);}{// 初始化ONS_API_OWNER消费组SubscriptionGroupConfig subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(MixAll.CID_ONSAPI_OWNER_GROUP);subscriptionGroupConfig.setConsumeBroadcastEnable(true);this.subscriptionGroupTable.put(MixAll.CID_ONSAPI_OWNER_GROUP, subscriptionGroupConfig);}}// 更新订阅配置，且更新内存数据版本号public void updateSubscriptionGroupConfig(final SubscriptionGroupConfig config) {SubscriptionGroupConfig old = this.subscriptionGroupTable.put(config.getGroupName(), config);if (old != null) {log.info("update subscription group config, old: {} new: {}", old, config);} else {log.info("create new subscription group, {}", config);}this.dataVersion.nextVersion();this.persist();}// 失效消费组public void disableConsume(final String groupName) {SubscriptionGroupConfig old = this.subscriptionGroupTable.get(groupName);if (old != null) {old.setConsumeEnable(false);this.dataVersion.nextVersion();}}// 查找指定消费组的订阅配置public SubscriptionGroupConfig findSubscriptionGroupConfig(final String group) {SubscriptionGroupConfig subscriptionGroupConfig = this.subscriptionGroupTable.get(group);if (null == subscriptionGroupConfig) {if (brokerController.getBrokerConfig().isAutoCreateSubscriptionGroup() || MixAll.isSysConsumerGroup(group)) {subscriptionGroupConfig = new SubscriptionGroupConfig();subscriptionGroupConfig.setGroupName(group);SubscriptionGroupConfig preConfig = this.subscriptionGroupTable.putIfAbsent(group, subscriptionGroupConfig);if (null == preConfig) {log.info("auto create a subscription group, {}", subscriptionGroupConfig.toString());}this.dataVersion.nextVersion();this.persist();}}return subscriptionGroupConfig;}// 将内存数据结构编码成字符串@Overridepublic String encode() {return this.encode(false);}// 获取配置文件路径@Overridepublic String configFilePath() {return BrokerPathConfigHelper.getSubscriptionGroupPath(this.brokerController.getMessageStoreConfig().getStorePathRootDir());}// 从字符串中恢复数据，写回内存数据结构@Overridepublic void decode(String jsonString) {if (jsonString != null) {SubscriptionGroupManager obj = RemotingSerializable.fromJson(jsonString, SubscriptionGroupManager.class);if (obj != null) {this.subscriptionGroupTable.putAll(obj.subscriptionGroupTable);this.dataVersion.assignNewOne(obj.dataVersion);this.printLoadDataWhenFirstBoot(obj);}}}// 将内存数据结构编码成字符串public String encode(final boolean prettyFormat) {return RemotingSerializable.toJson(this, prettyFormat);}// 当第一次启动时，打印加载数据时的日志private void printLoadDataWhenFirstBoot(final SubscriptionGroupManager sgm) {Iterator<Entry<String, SubscriptionGroupConfig>> it = sgm.getSubscriptionGroupTable().entrySet().iterator();while (it.hasNext()) {Entry<String, SubscriptionGroupConfig> next = it.next();log.info("load exist subscription group, {}", next.getValue().toString());}}public ConcurrentMap<String, SubscriptionGroupConfig> getSubscriptionGroupTable() {return subscriptionGroupTable;}public DataVersion getDataVersion() {return dataVersion;}// 删除指定消费组的订阅配置public void deleteSubscriptionGroupConfig(final String groupName) {SubscriptionGroupConfig old = this.subscriptionGroupTable.remove(groupName);if (old != null) {log.info("delete subscription group OK, subscription group:{}", old);this.dataVersion.nextVersion();this.persist();} else {log.warn("delete subscription group failed, subscription groupName: {} not exist", groupName);}}
}