RocketMQ源码解析-NameServer篇
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在这一篇我们主要来看下NameServer是怎样保存topic、broker、cluster这些信息的。
一、rocketmq-namesrv模块基本介绍
可以看到在它的源码中，namesrv其只有这些类(当然也有使用rocketMQ源码的其他的模块)。NamesrvController完成netty连接的初始化，然后DefaultRequestProcessor负责完成客户端具体要做的操作的派发，而关于注册信息相关的保存以及获取就是RouteInfoManager。
二、重要类介绍
1、DefaultRequestProcessor
这个类就是对客户端例如broker注册、producer获取对应broker信息等具体操作的派发
@Override
public RemotingCommand processRequest(ChannelHandlerContext ctx,
RemotingCommand request) throws RemotingCommandException
...........
switch (request.getCode())
..........
case RequestCode.REGISTER_BROKER:
Version brokerVersion = MQVersion.value2Version(request.getVersion());
if (brokerVersion.ordinal() >= MQVersion.Version.V3_0_11.ordinal())
return this.registerBrokerWithFilterServer(ctx, request);
else
return this.registerBroker(ctx, request);
case RequestCode.UNREGISTER_BROKER:
return this.unregisterBroker(ctx, request);
case RequestCode.GET_ROUTEINFO_BY_TOPIC:
return this.getRouteInfoByTopic(ctx, request);
case RequestCode.GET_BROKER_CLUSTER_INFO:
return this.getBrokerClusterInfo(ctx, request);
case RequestCode.WIPE_WRITE_PERM_OF_BROKER:
return this.wipeWritePermOfBroker(ctx, request);
case RequestCode.GET_ALL_TOPIC_LIST_FROM_NAMESERVER:
return getAllTopicListFromNameserver(ctx, request);
case RequestCode.DELETE_TOPIC_IN_NAMESRV:
return deleteTopicInNamesrv(ctx, request);
case RequestCode.GET_KVLIST_BY_NAMESPACE:
return this.getKVListByNamespace(ctx, request);
case RequestCode.GET_TOPICS_BY_CLUSTER:
return this.getTopicsByCluster(ctx, request);
case RequestCode.GET_SYSTEM_TOPIC_LIST_FROM_NS:
return this.getSystemTopicListFromNs(ctx, request);
case RequestCode.GET_UNIT_TOPIC_LIST:
return this.getUnitTopicList(ctx, request);
case RequestCode.GET_HAS_UNIT_SUB_TOPIC_LIST:
return this.getHasUnitSubTopicList(ctx, request);
case RequestCode.GET_HAS_UNIT_SUB_UNUNIT_TOPIC_LIST:
return this.getHasUnitSubUnUnitTopicList(ctx, request);
case RequestCode.UPDATE_NAMESRV_CONFIG:
return this.updateConfig(ctx, request);
case RequestCode.GET_NAMESRV_CONFIG:
return this.getConfig(ctx, request);
default:
break;
return null;
这里就有如RequestCode.REGISTER_BROKER其就是处理broker的注册请求的、RequestCode.GET_TOPICS_BY_CLUSTER客户端获取namesrv保存的topic信息、客户端获取以及注册的broker信息GET_BROKER_CLUSTER_INFO、GET_ROUTEINFO_BY_TOPIC获取Topic路由信息等。
1）、registerBroker
这个方法就是处理broker注册请求的
public RemotingCommand registerBroker(ChannelHandlerContext ctx,
RemotingCommand request) throws RemotingCommandException
.........
RegisterBrokerResult result = this.namesrvController.getRouteInfoManager().registerBroker(
requestHeader.getClusterName(),
requestHeader.getBrokerAddr(),
requestHeader.getBrokerName(),
requestHeader.getBrokerId(),
requestHeader.getHaServerAddr(),
topicConfigWrapper,
null,
ctx.channel()
);
responseHeader.setHaServerAddr(result.getHaServerAddr());
responseHeader.setMasterAddr(result.getMasterAddr());
byte[] jsonValue = this.namesrvController.getKvConfigManager().getKVListByNamespace(NamesrvUtil.NAMESPACE_ORDER_TOPIC_CONFIG);
response.setBody(jsonValue);
response.setCode(ResponseCode.SUCCESS);
response.setRemark(null);
return response;
这里就会交给RouteInfoManager来请求。
2）、getRouteInfoByTopic
public RemotingCommand getRouteInfoByTopic(ChannelHandlerContext ctx,
RemotingCommand request) throws RemotingCommandException
final RemotingCommand response = RemotingCommand.createResponseCommand(null);
final GetRouteInfoRequestHeader requestHeader =
(GetRouteInfoRequestHeader) request.decodeCommandCustomHeader(GetRouteInfoRequestHeader.class);
TopicRouteData topicRouteData = this.namesrvController.getRouteInfoManager().pickupTopicRouteData(requestHeader.getTopic());
if (topicRouteData != null)
if (this.namesrvController.getNamesrvConfig().isOrderMessageEnable())
String orderTopicConf =
this.namesrvController.getKvConfigManager().getKVConfig(NamesrvUtil.NAMESPACE_ORDER_TOPIC_CONFIG,
requestHeader.getTopic());
topicRouteData.setOrderTopicConf(orderTopicConf);
byte[] content = topicRouteData.encode();
response.setBody(content);
response.setCode(ResponseCode.SUCCESS);
response.setRemark(null);
return response;
response.setCode(ResponseCode.TOPIC_NOT_EXIST);
response.setRemark("No topic route info in name server for the topic: " + requestHeader.getTopic()
+ FAQUrl.suggestTodo(FAQUrl.APPLY_TOPIC_URL));
return response;
获取TopicRouteData路由信息也是交给RouteInfoManager。下面我们就来具体看下RouteInfoManager。
2、RouteInfoManager
public class RouteInfoManager
private static final InternalLogger log = InternalLoggerFactory.getLogger(LoggerName.NAMESRV_LOGGER_NAME);
private final static long BROKER_CHANNEL_EXPIRED_TIME = 1000 * 60 * 2;
private final ReadWriteLock lock = new ReentrantReadWriteLock();
private final HashMap<String/* topic */, List<QueueData>> topicQueueTable;
private final HashMap<String/* brokerName */, BrokerData> brokerAddrTable;
private final HashMap<String/* clusterName */, Set<String/* brokerName */>> clusterAddrTable;
private final HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;
private final HashMap<String/* brokerAddr */, List<String>/* Filter Server */> filterServerTable;
这个类我们主要是要知道这几个成员变量保存的值就可以了，因为关于broker注册、Topic路由信息都是获取这些变量中的值。
1）、前置介绍
在了解这些变量的时候，我有配置3台机的集群关系，建立了两个broker集群：DefaultCluster、DefaultCluster-2。
DefaultCluster由双主双从构成，其主要构成DefaultCluster集群，broker-xx.properties配置的部分内容
192.168.127.128：broker-a
brokerClusterName=DefaultCluster
brokerName=broker-a
brokerId=0
192.168.127.128：broker-b-s
brokerClusterName=DefaultCluster
brokerName=broker-b
brokerId=1
192.168.127.129：broker-a-s
brokerClusterName=DefaultCluster
brokerName=broker-a
brokerId=1
192.168.127.129：broker-b
brokerClusterName=DefaultCluster
brokerName=broker-b
brokerId=0
另一个集群我用的一台机192.168.127.130，正常不会怎样做(而且我发送消息的时候，发送的消息会在两个broker集群上都会有，要实现集群发消息隔离，应该需要不同集群分别注册到不同的nameServer上)
192.168.127.129：broker-c
brokerClusterName=DefaultCluster-2
brokerName=broker-c
brokerId=0
192.168.127.129：broker-a-s
brokerClusterName=DefaultCluster-2
brokerName=broker-c-s
brokerId=1
下面我们就来看下其具体保存的信息
2）、topicQueueTable(HashMap<String, List<QueueData>>)
public class QueueData implements Comparable<QueueData>
private String brokerName;
private int readQueueNums;
private int writeQueueNums;
private int perm;
private int topicSysFlag;
topicQueueTable就是保存topic与broker的对应关系，例如cluster_queue_topic，这个topic在我们搭建的集群中，其每台broker默认是4个队列，然后发送的消息会分布在3台broker的节点上面–broker-a、broker-b、broker-c，也就是说一个topic会有3*4个MessageQueue，例如在producer发送消息的时候，就会在12个MessageQueue中选一个：
同时这个topic的路由信息：
所以我们就可以通过topicQueueTable来知道topic发布在哪些broker上，以及整个topic的queue分布情况。
3）、brokerAddrTable(HashMap<String, BrokerData> )
public class BrokerData implements Comparable<BrokerData>
private String cluster;
private String brokerName;
private HashMap<Long/* brokerId */, String/* broker address */> brokerAddrs;
这个就是保存brokerName对应的broker启动的实例的主从实例的分布情况：
例如broker-b所属的集群是DefaultCluster，其有两个实例其中一个主节点(breokerId=0)在192.168.127.129，有一个从节点，这个从节点(brokerId>0)在192.168.127.128。
4）、clusterAddrTable(HashMap<String, Set<String>>)
这个就是保存集群有哪些brokerName。
5）、brokerLiveTable(HashMap<String, BrokerLiveInfo>)
这个主要是用来维护上次心跳的维持时间
private final HashMap<String/* brokerAddr */, BrokerLiveInfo> brokerLiveTable;
class BrokerLiveInfo
private long lastUpdateTimestamp;
private DataVersion dataVersion;
private Channel channel;
private String haServerAddr;
6）、registerBroker(REGISTER_BROKER)
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
this.lock.writeLock().lockInterruptibly();
Set<String> brokerNames = this.clusterAddrTable.get(clusterName);
if (null == brokerNames)
brokerNames = new HashSet<String>();
this.clusterAddrTable.put(clusterName, brokerNames);
brokerNames.add(brokerName);
boolean registerFirst = false;
BrokerData brokerData = this.brokerAddrTable.get(brokerName);
if (null == brokerData)
registerFirst = true;
brokerData = new BrokerData(clusterName, brokerName, new HashMap<Long, String>());
this.brokerAddrTable.put(brokerName, brokerData);
..........
String oldAddr = brokerData.getBrokerAddrs().put(brokerId, brokerAddr);
registerFirst = registerFirst || (null == oldAddr);
if (null != topicConfigWrapper
&& MixAll.MASTER_ID == brokerId)
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());
BrokerLiveInfo prevBrokerLiveInfo = this.brokerLiveTable.put(brokerAddr,
new BrokerLiveInfo(
System.currentTimeMillis(),
topicConfigWrapper.getDataVersion(),
channel,
haServerAddr));
.........
finally
this.lock.writeLock().unlock();
catch (Exception e)
log.error("registerBroker Exception", e);
return result;
private final ReadWriteLock lock = new ReentrantReadWriteLock();
private void createAndUpdateQueueData(final String brokerName, final TopicConfig topicConfig)
QueueData queueData = new QueueData();
queueData.setBrokerName(brokerName);
queueData.setWriteQueueNums(topicConfig.getWriteQueueNums());
queueData.setReadQueueNums(topicConfig.getReadQueueNums());
queueData.setPerm(topicConfig.getPerm());
queueData.setTopicSysFlag(topicConfig.getTopicSysFlag());
List<QueueData> queueDataList = this.topicQueueTable.get(topicConfig.getTopicName());
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
..........
这里更新的时候首先是上锁，然后就是将客户端实例broker注册的信息构建保存到上面的那些变量中。
7）、pickupTopicRouteData(GET_ROUTEINFO_BY_TOPIC)
public TopicRouteData pickupTopicRouteData(final String topic)
TopicRouteData topicRouteData = new TopicRouteData();
boolean foundQueueData = false;
boolean foundBrokerData = false;
Set<String> brokerNameSet = new HashSet<String>();
List<BrokerData> brokerDataList = new LinkedList<BrokerData>();
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