在日常的开发中,经常使用到各种消息中间件,用于系统间的数据交换与异步解耦。常用的消息中间件有Kafka、RabbitMQ、RocketMQ。不同的消息中间件在原理及使用上都有着自身的特点,比如Kafka和RocketMQ在协调点选择上就存在着很大的差异,Kafka是通过Zookeeper来进行协调,而RocketMQ通过自身的NameServer进行协调。本文主要介绍RocketMQ的NameServer的原理,并分析其源码。由于我只用过Kafka和RocketMQ,所以先简单比较下这两者在这方面的差异。
NameServer是专为RocketMQ设计的轻量级命名发现服务,代码小于1000行,具有简单、可集群横向扩展、无状态等特点。
下面我们详细分析每个类的具体功能。
NameServer
的启动是由NamesrvStartup
完成的,启动过程如下:
NamesrvConfig
和NettyServerConfig
;NamesrvController.initialize()
初始化NamesrvController
;若初始化失败,则直接关闭NamesrvController
;NamesrvController.start()
方法来开启NameServer
服务;ShutdownHookThread
服务。在JVM退出之前,调用NamesrvController.shutdown()
来进行关闭服务,释放资源;public class NamesrvStartup {
private static InternalLogger log;
private static Properties properties = null;
private static CommandLine commandLine = null;
public static void main(String[] args) {
main0(args);
}
public static NamesrvController main0(String[] args) {
try {
// 创建NamesrvController
NamesrvController controller = createNamesrvController(args);
// 启动NamesrvController
start(controller);
String tip = "The Name Server boot success. serializeType=" + RemotingCommand.getSerializeTypeConfigInThisServer();
log.info(tip);
System.out.printf("%s%n", tip);
return controller;
} catch (Throwable e) {
e.printStackTrace();
System.exit(-1);
}
return null;
}
public static NamesrvController createNamesrvController(String[] args) throws IOException, JoranException {
System.setProperty(RemotingCommand.REMOTING_VERSION_KEY, Integer.toString(MQVersion.CURRENT_VERSION));
//PackageConflictDetect.detectFastjson();
// 构建命令行
Options options = ServerUtil.buildCommandlineOptions(new Options());
commandLine = ServerUtil.parseCmdLine("mqnamesrv", args, buildCommandlineOptions(options), new PosixParser());
if (null == commandLine) {
System.exit(-1);
return null;
}
// nameServer配置参数
final NamesrvConfig namesrvConfig = new NamesrvConfig();
// netty server 配置参数
final NettyServerConfig nettyServerConfig = new NettyServerConfig();
nettyServerConfig.setListenPort(9876);
// 命令行参数是否包含配置文件
if (commandLine.hasOption('c')) {
// 获取配置文件路径
String file = commandLine.getOptionValue('c');
if (file != null) {
InputStream in = new BufferedInputStream(new FileInputStream(file));
properties = new Properties();
properties.load(in);
MixAll.properties2Object(properties, namesrvConfig);
MixAll.properties2Object(properties, nettyServerConfig);
namesrvConfig.setConfigStorePath(file);
System.out.printf("load config properties file OK, %s%n", file);
in.close();
}
}
// 是否打印参数
if (commandLine.hasOption('p')) {
// 都不打印
MixAll.printObjectProperties(null, namesrvConfig);
MixAll.printObjectProperties(null, nettyServerConfig);
System.exit(0);
}
// 设置命令行的参数,优先级高(会覆盖掉配置文件的配置项)
MixAll.properties2Object(ServerUtil.commandLine2Properties(commandLine), namesrvConfig);
// 未设置 rocketMQ home
if (null == namesrvConfig.getRocketmqHome()) {
System.out.printf("Please set the %s variable in your environment to match the location of the RocketMQ installation%n", MixAll.ROCKETMQ_HOME_ENV);
System.exit(-2);
}
// 配置Logger
LoggerContext lc = (LoggerContext) LoggerFactory.getILoggerFactory();
JoranConfigurator configurator = new JoranConfigurator();
configurator.setContext(lc);
lc.reset();
configurator.doConfigure(namesrvConfig.getRocketmqHome() + "/conf/logback_namesrv.xml");
log = InternalLoggerFactory.getLogger(LoggerName.NAMESRV_LOGGER_NAME);
// 控制台打印参数
MixAll.printObjectProperties(log, namesrvConfig);
MixAll.printObjectProperties(log, nettyServerConfig);
// 创建 NamesrvController
final NamesrvController controller = new NamesrvController(namesrvConfig, nettyServerConfig);
// 注册配置参数,防止丢失
// remember all configs to prevent discard
controller.getConfiguration().registerConfig(properties);
return controller;
}
public static NamesrvController start(final NamesrvController controller) throws Exception {
if (null == controller) {
throw new IllegalArgumentException("NamesrvController is null");
}
// 初始化NamesrvController
boolean initResult = controller.initialize();
// 初始化失败
if (!initResult) {
// 关闭NamesrvController
controller.shutdown();
// 关闭JVM
System.exit(-3);
}
// 注册关闭钩子方法:当JVM关闭的时候,先关闭NamesrvController
Runtime.getRuntime().addShutdownHook(new ShutdownHookThread(log, new Callable<Void>() {
@Override
public Void call() throws Exception {
// 关闭NamesrvController
controller.shutdown();
return null;
}
}));
// 启动NamesrvController
controller.start();
return controller;
}
public static void shutdown(final NamesrvController controller) {
controller.shutdown();
}
public static Options buildCommandlineOptions(final Options options) {
Option opt = new Option("c", "configFile", true, "Name server config properties file");
opt.setRequired(false);
options.addOption(opt);
opt = new Option("p", "printConfigItem", false, "Print all config item");
opt.setRequired(false);
options.addOption(opt);
return options;
}
}
NamesrvController
是NameServer
的核心控制类;
其中NettyServerConfig nettyServerConfig、RemotingServer remotingServer、ExecutorService remotingExecutor这三个属性与网络通信有关,NameServer与Broker、Producer、Consumer之间的网络通信,基于Netty。
/**
* NameServer配置属性:包括rocketmqHome(RocketMQ home目录),kvConfigPath(KV配置文件路径),configStorePath(Store配置文件路径)等
*/
private final NamesrvConfig namesrvConfig;
/**
* Netty的相关配置数据行
*/
private final NettyServerConfig nettyServerConfig;
/**
* NamesrvController 定时任务执行线程池,包含两个任务
*/
private final ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(new ThreadFactoryImpl("NSScheduledThread"));
/**
* KV配置属性管理器,主要管理NameServer的配置
*/
private final KVConfigManager kvConfigManager;
/**
* NameServer数据的载体,记录Broker,Topic等信息
*/
private final RouteInfoManager routeInfoManager;
/**
* Netty Server
*/
private RemotingServer remotingServer;
private BrokerHousekeepingService brokerHousekeepingService;
/**
* 执行Netty Server的线程池
*/
private ExecutorService remotingExecutor;
private Configuration configuration;
private FileWatchService fileWatchService;
initialize()
KVConfigManager
,从/${user.home}/namesrv/kvConfig.json
中加载NameServer
的配置信息,KVConfigManager将配置信息存储在configTable
中;NettyRemotingServer
,remotingServer
是NameServer
用于对外提供连接服务的;NettyRemotingServer
的线程池;RouteInfoManager
扫描brokerLiveTable
。判断每一个Broker
最近两分钟是否更新过。如果没有更新则把该Broker
的Channel
关闭,并清除相关数据。KVConfigManager
,打印configTable
的配置信息;// org.apache.rocketmq.namesrv.NamesrvController#initialize
public boolean initialize() {
// 1. 从/${user.home}/namesrv/kvConfig.json 中加载NameServer的配置
this.kvConfigManager.load();
// 2. 创建Netty Server
this.remotingServer = new NettyRemotingServer(this.nettyServerConfig, this.brokerHousekeepingService);
// 3. 创建Netty Server执行的线程池
// 该参数目前主要用于NameServer的默认业务线程池,处理诸如broker,product,consume与NameServer的所有交互命令
this.remotingExecutor =
Executors.newFixedThreadPool(nettyServerConfig.getServerWorkerThreads(), new ThreadFactoryImpl("RemotingExecutorThread_"));
// 4. 注册NameServer服务接受请求的处理类
this.registerProcessor();
// 5. 每隔10s扫描broker,维护当前存活的Broker信息
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
NamesrvController.this.routeInfoManager.scanNotActiveBroker();
}
}, 5, 10, TimeUnit.SECONDS);
// 6. 每隔10s打印KVConfig信息
this.scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
NamesrvController.this.kvConfigManager.printAllPeriodically();
}
}, 1, 10, TimeUnit.MINUTES);
...
return true;
}
/**
* 注册接收请求的处理类
*/
// org.apache.rocketmq.namesrv.NamesrvController#registerProcessor
private void registerProcessor() {
if (namesrvConfig.isClusterTest()) {
this.remotingServer.registerDefaultProcessor(new ClusterTestRequestProcessor(this, namesrvConfig.getProductEnvName()),
this.remotingExecutor);
} else {
// 注册默认的处理类DefaultRequestProcessor,所有的请求均由该处理类的processRequest方法来处理
this.remotingServer.registerDefaultProcessor(new DefaultRequestProcessor(this), this.remotingExecutor);
}
}
start()
// org.apache.rocketmq.namesrv.NamesrvController#start
public void start() throws Exception {
// 启动Netty Server
this.remotingServer.start();
if (this.fileWatchService != null) {
this.fileWatchService.start();
}
}
shutdown()
// org.apache.rocketmq.namesrv.NamesrvController#shutdown
public void shutdown() {
// 关闭Netty server
this.remotingServer.shutdown();
// 关闭处理Netty Server的线程池
this.remotingExecutor.shutdown();
// 关闭定时任务线程池
this.scheduledExecutorService.shutdown();
if (this.fileWatchService != null) {
this.fileWatchService.shutdown();
}
}
NameServer
默认注册的是DefaultRequestProcessor
处理器。
如果设置了NamesrvConfig.clusterTest=true
,则会注册ClusterTestRequestProcessor
处理器。
ClusterTestRequestProcessor
继承DefaultRequestProcessor
;
ClusterTestRequestProcessor
仅重写了getRouteInfoByTopic()
方法。
判断如果获取不到topicRouteData
数据,则会去其它的NameServer
上查找该数据并返回。
DefaultRequestProcessor
通过processRequest()
方法来处理客户端发过来的请求。该方法通过request的code值来判断是属于哪种类型的操作。发现接收到的所有请求操作的数据都保存在RouteInfoManager
类中,所有的操作都是对RouteInfoManager
类的操作。
通过 processRequest 方法来处理客户端发过来的请求。
所有请求的操作说明如下:
requectcode | 说明 |
---|---|
PUT_KV_CONFIG | 向Namesrv追加KV配置 |
GET_KV_CONFIG | 从Namesrv获取KV配置 |
DELETE_KV_CONFIG | 从Namesrv获取KV配置 |
QUERY_DATA_VERSION | 获取版本信息 |
REGISTER_BROKER | 注册一个Broker,数据都是持久化的,如果存在则覆盖配置 |
UNREGISTER_BROKER | 卸载一个Broker,数据都是持久化的 |
GET_ROUTEINTO_BY_TOPIC | 根据Topic获取Broker Name、Topic配置信息 |
GET_BROKER_CLUSTER_INFO | 获取注册到NameServer的所有Broker集群信息 |
WIPE_WRITE_PERM_OF_BROKER | 去掉BrokerName的写权限 |
GET_ALL_TOPIC_LIST_FROM_NAMESERVER | 从NameServer获取完整Topic列表 |
DELETE_TOPIC_IN_NAMESRV | 从Namesrv删除Topic配置 |
GET_KVLIST_BY_NAMESPACE | 通过NameSpace获取所有的KV List |
GET_TOPICS_BY_CLUSTER | 获取指定集群下的所有Topic |
GET_SYSTEM_TOPIC_LIST_FROM_NS | 获取所有系统内置Topic列表 |
GET_UNIT_TOPIC_LIST | 单元化相关Topic |
GET_HAS_UNIT_SUB_TOPIC_LIST | 获取含有单元化订阅组的Topic列表 |
GET_HAS_UNIT_SUB_UNUNIT_TOPIC_LIST | 获取含有单元化订阅组的非单元化 |
UPDATE_NAMESRV_CONFIG | 更新NameServer配置 |
根据 processRequest()
方法分析源码,发现接收到的所有请求操作的数据都保存在KVConfigManager
和RouteInfoManager
类中,所有的操作都是对KVConfigManager
和RouteInfoManager
类的操作。
KVConfigManager
KVConfigManager
主要负责读取或变更NameServer
的配置属性,加载NamesrvConfig
中配置的配置文件到内存,包含以下功能:
/${user.home}/namesrv/kvConfig.json
加载到内存;DefaultRequestProcessor
调用,由于内容比较简单,直接阅读源码即可。// org.apache.rocketmq.namesrv.kvconfig.KVConfigManager
public class KVConfigManager {
private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.NAMESRV_LOGGER_NAME);
private final NamesrvController namesrvController;
/**
* 读写锁,尽最大程度提高线程的并发度,因为使用非线程安全的容器。
*/
private final ReadWriteLock lock = new ReentrantReadWriteLock();
/**
* 使用轻量级HashMap,存储配置项
*/
private final HashMap<String/* Namespace */, HashMap<String/* Key */, String/* Value */>> configTable = new HashMap<String, HashMap<String, String>>();
public KVConfigManager(NamesrvController namesrvController) {
this.namesrvController = namesrvController;
}
/**
* 将配置项文件加载到内存
*/
public void load() {
String content = null;
try {
// 加载配置文件内容
content = MixAll.file2String(this.namesrvController.getNamesrvConfig().getKvConfigPath());
} catch (IOException e) {
log.warn("Load KV config table exception", e);
}
if (content != null) {
// 反序列化
KVConfigSerializeWrapper kvConfigSerializeWrapper =
KVConfigSerializeWrapper.fromJson(content, KVConfigSerializeWrapper.class);
if (null != kvConfigSerializeWrapper) {
this.configTable.putAll(kvConfigSerializeWrapper.getConfigTable());
log.info("load KV config table OK");
}
}
}
/**
* 为相应的命名空间添加配置项
* @param namespace 命名空间
* @param key 配置项
* @param value 配置值
*/
public void putKVConfig(final String namespace, final String key, final String value) {
try {
// 加写锁
this.lock.writeLock().lockInterruptibly();
try {
// 添加配置项
HashMap<String, String> kvTable = this.configTable.get(namespace);
if (null == kvTable) {
kvTable = new HashMap<String, String>();
this.configTable.put(namespace, kvTable);
log.info("putKVConfig create new Namespace {}", namespace);
}
final String prev = kvTable.put(key, value);
if (null != prev) {
log.info("putKVConfig update config item, Namespace: {} Key: {} Value: {}",
namespace, key, value);
} else {
log.info("putKVConfig create new config item, Namespace: {} Key: {} Value: {}",
namespace, key, value);
}
} finally {
// 释放写锁
this.lock.writeLock().unlock();
}
} catch (InterruptedException e) {
log.error("putKVConfig InterruptedException", e);
}
// 持久化到文件
this.persist();
}
/**
* 配置项持久化到文件
*/
public void persist() {
try {
this.lock.readLock().lockInterruptibly();
try {
KVConfigSerializeWrapper kvConfigSerializeWrapper = new KVConfigSerializeWrapper();
kvConfigSerializeWrapper.setConfigTable(this.configTable);
String content = kvConfigSerializeWrapper.toJson();
if (null != content) {
MixAll.string2File(content, this.namesrvController.getNamesrvConfig().getKvConfigPath());
}
} catch (IOException e) {
log.error("persist kvconfig Exception, "
+ this.namesrvController.getNamesrvConfig().getKvConfigPath(), e);
} finally {
this.lock.readLock().unlock();
}
} catch (InterruptedException e) {
log.error("persist InterruptedException", e);
}
}
/**
* 删除指定命名空间的配置项
* @param namespace 命名空间
* @param key 配置项
*/
public void deleteKVConfig(final String namespace, final String key) {
try {
this.lock.writeLock().lockInterruptibly();
try {
HashMap<String, String> kvTable = this.configTable.get(namespace);
if (null != kvTable) {
String value = kvTable.remove(key);
log.info("deleteKVConfig delete a config item, Namespace: {} Key: {} Value: {}",
namespace, key, value);
}
} finally {
this.lock.writeLock().unlock();
}
} catch (InterruptedException e) {
log.error("deleteKVConfig InterruptedException", e);
}
// 持久化到文件
this.persist();
}
/**
* 根据指定命名空间获取所有配置项
* @param namespace 命名空间
* @return 二进制的 KVTable json
*/
public byte[] getKVListByNamespace(final String namespace) {
try {
this.lock.readLock().lockInterruptibly();
try {
HashMap<String, String> kvTable = this.configTable.get(namespace);
if (null != kvTable) {
KVTable table = new KVTable();
table.setTable(kvTable);
return table.encode();
}
} finally {
this.lock.readLock().unlock();
}
} catch (InterruptedException e) {
log.error("getKVListByNamespace InterruptedException", e);
}
return null;
}
/**
* 根据指定命名空间、配置项获取配置值
* @param namespace 命名空间
* @param key 配置项
* @return
*/
public String getKVConfig(final String namespace, final String key) {
try {
this.lock.readLock().lockInterruptibly();
try {
HashMap<String, String> kvTable = this.configTable.get(namespace);
if (null != kvTable) {
return kvTable.get(key);
}
} finally {
this.lock.readLock().unlock();
}
} catch (InterruptedException e) {
log.error("getKVConfig InterruptedException", e);
}
return null;
}
/**
* 定时打印所有配置信息,在NamesrvController中的定时任务中执行
*/
public void printAllPeriodically() {
try {
this.lock.readLock().lockInterruptibly();
try {
log.info("--------------------------------------------------------");
{
log.info("configTable SIZE: {}", this.configTable.size());
Iterator<Entry<String, HashMap<String, String>>> it =
this.configTable.entrySet().iterator();
while (it.hasNext()) {
Entry<String, HashMap<String, String>> next = it.next();
Iterator<Entry<String, String>> itSub = next.getValue().entrySet().iterator();
while (itSub.hasNext()) {
Entry<String, String> nextSub = itSub.next();
log.info("configTable NS: {} Key: {} Value: {}", next.getKey(), nextSub.getKey(),
nextSub.getValue());
}
}
}
} finally {
this.lock.readLock().unlock();
}
} catch (InterruptedException e) {
log.error("printAllPeriodically InterruptedException", e);
}
}
}
RouteInfoManager
RouteInfoManager
作为NameServer
数据的载体,记录Broker
、Topic
、QueueData
等信息。
Broker在启动时会将Broker
信息、Topic
信息、QueueData
信息注册到所有的NameServer
上,并和所有NameServer
节点保持长连接,之后也会定时注册信息;
Producer、Consumer也会和其中一个NameServer
节点保持长连接,定时从NameServer中获取Topic路由信息;
四者之间的数据交互如下图。
RouteInfoManager
主要具备以下功能:
NamesrvController
定时任务每隔10S扫描一次所有的broker,根据心跳包的时间得知broker的状态。因此该表存储的信息不是实时的,当一个Master 宕掉后,消息生产者无法感知,可能继续向Down掉的Master发送消息,导致失败。// org.apache.rocketmq.namesrv.routeinfo.RouteInfoManager
/**
* NameServer与Broker空闲时长,默认2分钟,在2分钟内Nameserver没有收到Broker的心跳包,则关闭该连接。单位(毫秒)
*/
private final static long BROKER_CHANNEL_EXPIRED_TIME = 1000 * 60 * 2;
/**
* 读写锁,保护非线程安全容器HashMap
*/
private final ReadWriteLock lock = new ReentrantReadWriteLock();
/**
* topic-队列映射表,记录一个主题的队列分布在哪些Broker上,每个Broker上存在该主题的队列个数
*/
private final HashMap<String/* topic */, List<QueueData>> topicQueueTable;
/**
* broker地址映射表,存储所有broker信息,brokerName为key,BrokerData信息描述每一个broker信息
*/
private final HashMap<String/* brokerName */, BrokerData> brokerAddrTable;
/**
* 集群-broker映射表,每个集群包含哪些broker
*/
private final HashMap<String/* clusterName */, Set<String/* brokerName */>> clusterAddrTable;
/**
* broker地址-broker存活信息映射表,当前存活的Broker,该信息不是实时的
*/
private final HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;
/**
* broker地址-过滤服务器映射表
* Filter Server是消息的过滤服务器,一个Broker可以对应多个Filter Server
*/
private final HashMap<String/* brokerAddr */, List<String>/* Filter Server */> filterServerTable;
QueueData: 队列数据结构
// org.apache.rocketmq.common.protocol.route.QueueData
public class QueueData implements Comparable<QueueData> {
private String brokerName; // broker名称
private int readQueueNums; // 读队列个数
private int writeQueueNums; // 写队列个数
private int perm; // 权限操作
private int topicSynFlag; // 同步复制还是异步复制
}
BrokerData保存着Broker的信息。
// org.apache.rocketmq.common.protocol.route.BrokerData
public class BrokerData implements Comparable<BrokerData> {
private String cluster; // 集群名称
private String brokerName; // broker名称
private HashMap<Long/* brokerId */, String/* broker address */> brokerAddrs; // brokerId-broker地址映射
private final Random random = new Random();
/**
* 从注册的地址中选择一个broker地址(优先选择master)
* 如果没有master地址,则随机选择一个slave地址
* @return Broker address.
*/
public String selectBrokerAddr() {
// MixAll.MASTER_ID = 0
String addr = this.brokerAddrs.get(MixAll.MASTER_ID);
if (addr == null) {
List<String> addrs = new ArrayList<String>(brokerAddrs.values());
return addrs.get(random.nextInt(addrs.size()));
}
return addr;
}
}
BrokerLiveInfo保存Broker与NameServer的心跳数据。
// org.apache.rocketmq.namesrv.routeinfo.BrokerLiveInfo
class BrokerLiveInfo {
private long lastUpdateTimestamp; // 最近更新时间
private DataVersion dataVersion; // 数据版本
private Channel channel; // 与该broker连接的通道
private String haServerAddr;
}
// org.apache.rocketmq.namesrv.routeinfo.RouteInfoManager#deleteTopic
public void deleteTopic(final String topic) {
try {
try {
this.lock.writeLock().lockInterruptibly();
// 从topic-队列映射表中移除
this.topicQueueTable.remove(topic);
} finally {
this.lock.writeLock().unlock();
}
} catch (Exception e) {
log.error("deleteTopic Exception", e);
}
}
/**
* 注册broker
* @param clusterName 所属集群
* @param brokerAddr broker ip地址
* @param brokerName broker 名称
* @param brokerId broker id, 0 表示master
* @param haServerAddr
* @param topicConfigWrapper
* @param filterServerList
* @param channel
* @return
*/
public RegisterBrokerResult registerBroker(
final String clusterName,
final String brokerAddr,
final String brokerName,
final long brokerId,
final String haServerAddr,
final TopicConfigSerializeWrapper topicConfigWrapper,
final List<String> filterServerList,
final Channel channel) {
RegisterBrokerResult result = new RegisterBrokerResult();
try {
try {
// 加写锁
this.lock.writeLock().lockInterruptibly();
// 根据集群名获取所有Broker
Set<String> brokerNames = this.clusterAddrTable.get(clusterName);
if (null == brokerNames) {
// 若该集群下无注册的Broker,则初始化列表
brokerNames = new HashSet<String>();
this.clusterAddrTable.put(clusterName, brokerNames);
}
// 将待注册的Broker名称加入Broker表
brokerNames.add(brokerName);
// 是否首次注册
boolean registerFirst = false;
// 根据Broker名称从Broker表中获取BrokerData
BrokerData brokerData = this.brokerAddrTable.get(brokerName);
if (null == brokerData) {
// 若不存在,则本次为首次注册
registerFirst = true;
// 创建BrokerData,初始化broker地址列表为空
brokerData = new BrokerData(clusterName, brokerName, new HashMap<Long, String>());
// 加入Broker表
this.brokerAddrTable.put(brokerName, brokerData);
}
Map<Long, String> brokerAddrsMap = brokerData.getBrokerAddrs();
//Switch slave to master: first remove <1, IP:PORT> in namesrv, then add <0, IP:PORT>
//The same IP:PORT must only have one record in brokerAddrTable
Iterator<Entry<Long, String>> it = brokerAddrsMap.entrySet().iterator();
// 同一个 IP:PORT 在 brokerAddrTable中只能有一条记录
while (it.hasNext()) {
Entry<Long, String> item = it.next();
// 检查对应的broker地址在broker地址表中是否存在,如果brokerId不一致,则需要先移除掉
if (null != brokerAddr && brokerAddr.equals(item.getValue()) && brokerId != item.getKey()) {
it.remove();
}
}
// 将地址保存
String oldAddr = brokerAddrsMap.put(brokerId, brokerAddr);
// 判断是否首次注册
registerFirst = registerFirst || (null == oldAddr);
// 是否为master broker
if (null != topicConfigWrapper
&& MixAll.MASTER_ID == brokerId) {
// broker的配置变更了或者属于首次注册,注册QueueData
if (this.isBrokerTopicConfigChanged(brokerAddr, topicConfigWrapper.getDataVersion()) || registerFirst) {
ConcurrentMap<String, TopicConfig> tcTable = topicConfigWrapper.getTopicConfigTable();
if (tcTable != null) {
for (Map.Entry<String, TopicConfig> entry : tcTable.entrySet()) {
this.createAndUpdateQueueData(brokerName, entry.getValue());
}
}
}
}
// 注册broker存活信息
BrokerLiveInfo prevBrokerLiveInfo = this.brokerLiveTable.put(brokerAddr,
new BrokerLiveInfo(
System.currentTimeMillis(),
topicConfigWrapper.getDataVersion(),
channel,
haServerAddr));
// 新注册
if (null == prevBrokerLiveInfo) {
log.info("new broker registered, {} HAServer: {}", brokerAddr, haServerAddr);
}
// 过滤服务器列表是否为空
if (filterServerList != null) {
if (filterServerList.isEmpty()) {
this.filterServerTable.remove(brokerAddr);
} else {
this.filterServerTable.put(brokerAddr, filterServerList);
}
}
// 待注册的broker不是master,为salve,需要将master的地址返回
if (MixAll.MASTER_ID != brokerId) {
// 获取master的地址
String masterAddr = brokerData.getBrokerAddrs().get(MixAll.MASTER_ID);
if (masterAddr != null) {
// 获取master的存活信息
BrokerLiveInfo brokerLiveInfo = this.brokerLiveTable.get(masterAddr);
// master存活
if (brokerLiveInfo != null) {
// 设置该master为HA服务
result.setHaServerAddr(brokerLiveInfo.getHaServerAddr());
// 设置master地址,这样salve就能和master通信了
result.setMasterAddr(masterAddr);
}
}
}
} finally {
// 释放写锁
this.lock.writeLock().unlock();
}
} catch (Exception e) {
log.error("registerBroker Exception", e);
}
return result;
}
/**
* 指定broker ip的dataVersion是否变更
* @param brokerAddr
* @param dataVersion
* @return
*/
public boolean isBrokerTopicConfigChanged(final String brokerAddr, final DataVersion dataVersion) {
// 查询数据版本
DataVersion prev = queryBrokerTopicConfig(brokerAddr);
// 比较版本是否一致
return null == prev || !prev.equals(dataVersion);
}
/**
* 根据 broker ip查询dataVersion
* @param brokerAddr
* @return
*/
public DataVersion queryBrokerTopicConfig(final String brokerAddr) {
// 从存活信息表中查询
BrokerLiveInfo prev = this.brokerLiveTable.get(brokerAddr);
if (prev != null) {
return prev.getDataVersion();
}
return null;
}
/**
* 创建或更新QueueData
* @param brokerName
* @param topicConfig
*/
private void createAndUpdateQueueData(final String brokerName, final TopicConfig topicConfig) {
QueueData queueData = new QueueData();
// 设置brokerName
queueData.setBrokerName(brokerName);
// 设置写队列个数
queueData.setWriteQueueNums(topicConfig.getWriteQueueNums());
// 设置读队列个数
queueData.setReadQueueNums(topicConfig.getReadQueueNums());
// 设置操作权限
queueData.setPerm(topicConfig.getPerm());
// 设置同步、异步标志
queueData.setTopicSynFlag(topicConfig.getTopicSysFlag());
// 获取指定topic名称的QueueData列表
List<QueueData> queueDataList = this.topicQueueTable.get(topicConfig.getTopicName());
// 若不存在,直接插入
if (null == queueDataList) {
queueDataList = new LinkedList<QueueData>();
queueDataList.add(queueData);
this.topicQueueTable.put(topicConfig.getTopicName(), queueDataList);
log.info("new topic registered, {} {}", topicConfig.getTopicName(), queueData);
} else {
// 是否需要新增标志
boolean addNewOne = true;
Iterator<QueueData> it = queueDataList.iterator();
while (it.hasNext()) {
QueueData qd = it.next();
if (qd.getBrokerName().equals(brokerName)) {
// 没有变更, 不需要更新
if (qd.equals(queueData)) {
addNewOne = false;
} else {
// 需要更新,先移除
log.info("topic changed, {} OLD: {} NEW: {}", topicConfig.getTopicName(), qd,
queueData);
it.remove();
}
}
}
// 需要更新
if (addNewOne) {
queueDataList.add(queueData);
}
}
}
当Broker下线,或者之间的长连接断开后,就会将该Broker的信息注销掉。Broker与NameServer交互时序图如下:
/**
* 注销broker
* @param clusterName 集群名称
* @param brokerAddr broker 地址
* @param brokerName broker 名称
* @param brokerId broker id
*/
public void unregisterBroker(
final String clusterName,
final String brokerAddr,
final String brokerName,
final long brokerId) {
try {
try {
// 加写锁
this.lock.writeLock().lockInterruptibly();
// 存活信息表中移除broker地址
BrokerLiveInfo brokerLiveInfo = this.brokerLiveTable.remove(brokerAddr);
log.info("unregisterBroker, remove from brokerLiveTable {}, {}",
brokerLiveInfo != null ? "OK" : "Failed",
brokerAddr
);
// filterServerTable移除broker地址
this.filterServerTable.remove(brokerAddr);
// 是否从brokerAddrTable移除brokerName标志
boolean removeBrokerName = false;
//
BrokerData brokerData = this.brokerAddrTable.get(brokerName);
if (null != brokerData) {
// 移除brokerData中的该broker
String addr = brokerData.getBrokerAddrs().remove(brokerId);
log.info("unregisterBroker, remove addr from brokerAddrTable {}, {}",
addr != null ? "OK" : "Failed",
brokerAddr
);
// 如果该brokerName下无机器了,则从brokerAddrTable中移除brokerName
if (brokerData.getBrokerAddrs().isEmpty()) {
this.brokerAddrTable.remove(brokerName);
log.info("unregisterBroker, remove name from brokerAddrTable OK, {}",
brokerName
);
// 移除brokerName标志置true
removeBrokerName = true;
}
}
// 已经从brokerAddrTable移除了brokerName,则需要将clusterAddrTable中的brokerName也移除掉
if (removeBrokerName) {
Set<String> nameSet = this.clusterAddrTable.get(clusterName);
if (nameSet != null) {
// 移除brokerName
boolean removed = nameSet.remove(brokerName);
log.info("unregisterBroker, remove name from clusterAddrTable {}, {}",
removed ? "OK" : "Failed",
brokerName);
// 该clusterName下无其他broker,则将cluster也整体删掉
if (nameSet.isEmpty()) {
this.clusterAddrTable.remove(clusterName);
log.info("unregisterBroker, remove cluster from clusterAddrTable {}",
clusterName
);
}
}
// 移除该brokerName下的所有Topic
this.removeTopicByBrokerName(brokerName);
}
} finally {
// 释放写锁
this.lock.writeLock().unlock();
}
} catch (Exception e) {
log.error("unregisterBroker Exception", e);
}
}
private void removeTopicByBrokerName(final String brokerName) {
Iterator<Entry<String, List<QueueData>>> itMap = this.topicQueueTable.entrySet().iterator();
// 遍历topicQueueTable,释放brokerName下的队列
while (itMap.hasNext()) {
Entry<String, List<QueueData>> entry = itMap.next();
String topic = entry.getKey();
List<QueueData> queueDataList = entry.getValue();
Iterator<QueueData> it = queueDataList.iterator();
while (it.hasNext()) {
QueueData qd = it.next();
if (qd.getBrokerName().equals(brokerName)) {
log.info("removeTopicByBrokerName, remove one broker's topic {} {}", topic, qd);
it.remove();
}
}
// 该topic下的队列为空,则释放topic
if (queueDataList.isEmpty()) {
log.info("removeTopicByBrokerName, remove the topic all queue {}", topic);
itMap.remove();
}
}
}