HRegionServer 启动分析
HRegionServer的初始化到底做了哪些事情，以线程的维度应该能比较清晰的说明，也便于以后更进一步深入的分析。如果能弄清楚每个线程的职责分工，基本上HRegionServer的原理就明白了
HRegionServer的初始化
1.1）实例化
一个典型的栈快照
Thread[main](Suspended)
WritableRpcEngine$Server(HBaseServer).<init>(String,int,Class<Writable>,int,int,Configuration,String,int)line:1447
WritableRpcEngine$Server.<init>(Object,Class<?>[],Configuration,String,int,int,int,boolean,int)line:296
WritableRpcEngine.getServer(Class<VersionedProtocol>,Object,Class<?>[],String,int,int,int,boolean,Configuration,int)line:245
WritableRpcEngine.getServer(Class,Object,Class[],String,int,int,int,boolean,Configuration,int)line:55
HBaseRPC.getServer(Class,Object,Class<?>[],String,int,int,int,boolean,Configuration,int)line:401
HBaseRPC.getServer(Object,Class<?>[],String,int,int,int,boolean,Configuration,int)line:390
HRegionServer.<init>(Configuration)line:385
NativeConstructorAccessorImpl.newInstance0(Constructor,Object[])line:notavailable[nativemethod]
NativeConstructorAccessorImpl.newInstance(Object[])line:39
DelegatingConstructorAccessorImpl.newInstance(Object[])line:27
Constructor<T>.newInstance(Object...)line:513
HRegionServer.constructRegionServer(Class<HRegionServer>,Configuration)line:3225
HRegionServerCommandLine.start()line:60
HRegionServerCommandLine.run(String[])line:75
ToolRunner.run(Configuration,Tool,String[])line:65
HRegionServerCommandLine(ServerCommandLine).doMain(String[])line:76
HRegionServer.main(String[])line:3251
此时正在实例化HRegionServer
初始化了一个监听线程HBaseServer$Listener
初始化并启动了10个（默认、可调）请求线程HBaseServer$Listener$Reader：
将网络输入字节转化为Call,放入callQueue或者priorityCallQueue
DaemonThread[IPCReader0-9 onport60020]
初始化一个响应线程HBaseServer$Responder
初始化LruBlockCache
启动缓存逐出线程LruBlockCache$EvictionThread：
平时不干活，当缓存的内存过大会被唤醒，然后开始释放内存但不会使结果小于最小的内存
DaemonThread[LruBlockCache.EvictionThread]
启动一个定时的缓存使用统计线程LruBlockCache$StatisticsThread
仅仅在debug模式会将缓存统计信息打入日志
DaemonThread[LRUStatistics#0]
1.2）启动
一个典型的栈快照
Thread[main](Suspended)
HRegionServer.startRegionServer(HRegionServer,String)line:3207HRegionServer.startRegionServer(HRegionServer)line:3191
HRegionServerCommandLine.start()line:61
HRegionServerCommandLine.run(String[])line:75
ToolRunner.run(Configuration,Tool,String[])line:65
HRegionServerCommandLine(ServerCommandLine).doMain(String[])line:76
HRegionServer.main(String[])line:3251
启动一个启动线程HRegionServer(本身实现了runnable)：
用于向HMaster汇报
Thread[regionserver60020]
初始化zookeeper[HRegionServer.initializeZooKeeper]
启动zookeeperclient，实例化ZooKeeper，触发两个线程
ClientCnxn$SendThread
DaemonThread[regionserver60020-SendThread(vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net:2181)]
ClientCnxn$EventThread
DaemonThread[regionserver60020-EventThread]
实例化CatalogTracker跟踪-ROOT-和.META.，其中同样会实例化ZooKeeper，触发两个线程
ClientCnxn$SendThread
DaemonThread[regionserver60020-SendThread(vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net:2181)]
ClientCnxn$EventThread
DaemonThread[regionserver60020-EventThread]
实例化线程[HRegionServer.initializeThreads]
实例化MemStoreFlusher
实例化CompactSplitThread
实例化Leases线程
Leases线程一种超时检查机制，某些客户调用涉及到耗时操作比如rowlock或者scan,都会在Leases线程中注册，一旦超时，Leases线程会调用一个注册的回调进行处理
在zookeeper注册一个znode
设置复制
实例化Hlog
实例化一个logroll线程LogRoller：会定期检查log是否超过固定尺寸，超过则roll
实例化Hlog的的SequenceFileLogWriter，
启动一个LeaseCheck线程[org.apache.hadoop.hdfs.DFSClient$LeaseChecker]
（此Lease非彼Lease，前者是haddop,后者属hbase)
DaemonThread[LeaseChecker]
启动org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$DataStreamer
DaemonThread[DataStreamerforfile/hbase/.logs/vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net,60020,1335341948662/vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net%2C60020%2C1335341948662.1335342838477blockblk_-2454170457116903777_1073]
启动一个Hlog$LogSyncer线程同步writerbuffer中的数据
DaemonThread[regionserver60020.logSyncer]
会触发启动org.apache.hadoop.hdfs.DFSClient$DFSOutputStream$ResponseProcessor线程
DaemonThread[ResponseProcessorforblockblk_-2454170457116903777_1073]
启动服务线程
实例化一堆线程池
启动前面提到的LogRoller线程
DaemonThread[regionserver60020.logRoller]
启动前面提到的MemStoreFlusher线程
DaemonThread[regionserver60020.cacheFlusher]
启动前面提到的CompactSplitThread线程
DaemonThread[regionserver60020.compactionChecker]
启动前面提到的Leases线程
DaemonThread[regionserver60020.leaseChecker]
启动一个jettyserver
启动一个监听线程
Thread[1879358054@qtp-1524522201-0]
启动一个select线程
Thread[1185851599@[email protected]:60030]
也会触发启动一个java.util.TimerThread，
不知道干嘛个
DaemonThread[Timer-0]
启动RPCserver
启动HBaseServer$Responder线程
DaemonThread[IPCServerResponder]
启动HBaseServer$Listener线程
DaemonThread[IPCServerlisteneron60020]
启动10个Handler线程：处理callQueue中的请求
DaemonThread[IPCServerhandler 0-9on60020]
启动10个优先级Handler线程：处理priorityCallQueue中的请求
DaemonThread[PRIIPCServerhandler0-9on60020]
附上所有线程（见上面标绿的地方）
JavaHotSpot(TM)64-BitServerVM[10.20.156.53:8000]
DaemonThread[IPCReader0onport60020](Running)DaemonThread[IPCReader1onport60020](Running)
DaemonThread[IPCReader2onport60020](Running)
DaemonThread[IPCReader3onport60020](Running)
DaemonThread[IPCReader4onport60020](Running)
DaemonThread[IPCReader5onport60020](Running)
DaemonThread[IPCReader6onport60020](Running)
DaemonThread[IPCReader7onport60020](Running)
DaemonThread[IPCReader8onport60020](Running)
DaemonThread[IPCReader9onport60020](Running)
DaemonThread[LruBlockCache.EvictionThread](Running)
DaemonThread[LRUStatistics#0](Running)
Thread[regionserver60020](Running)
DaemonThread[regionserver60020-SendThread(vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net:2181)](Running)
DaemonThread[regionserver60020-EventThread](Running)
DaemonThread[regionserver60020-SendThread(vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net:2181)](Running)
DaemonThread[regionserver60020-EventThread](Running)
DaemonThread[LeaseChecker](Running)
DaemonThread[DataStreamerforfile/hbase/.logs/vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net,60020,1335341948662/vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net%2C60020%2C1335341948662.1335342838477blockblk_-2454170457116903777_1073](Running) DaemonThread[regionserver60020.logSyncer](Running)
DaemonThread[regionserver60020.logRoller](Running)
DaemonThread[regionserver60020.compactionChecker](Running)
DaemonThread[regionserver60020.cacheFlusher](Running)
DaemonThread[regionserver60020.leaseChecker](Running)
Thread[1879358054@qtp-1524522201-0](Running)
Thread[1185851599@[email protected]:60030](Running)
DaemonThread[ResponseProcessorforblockblk_-2454170457116903777_1073](Running)
DaemonThread[Timer-0](Running)
DaemonThread[IPCServerlisteneron60020](Running)
DaemonThread[IPCServerResponder](Running)
DaemonThread[IPCClient(47)connectiontovm-cbu-dev-otd-165-74.hst.bjc.kfc.alidc.net/10.20.165.74:60000fromadmin](Running)
Thread[SplitLogWorker-vm-cbu-dev-otd-156-53.hst.bjc.kfc.alidc.net,60020,1335341948662](Running)
DaemonThread[IPCServerhandler4on60020](Running)
DaemonThread[PRIIPCServerhandler3on60020](Running)
DaemonThread[IPCServerhandler1on60020](Running)
DaemonThread[IPCServerhandler9on60020](Running)
DaemonThread[IPCServerhandler7on60020](Running)
DaemonThread[IPCServerhandler5on60020](Running)
DaemonThread[IPCServerhandler6on60020](Running)
DaemonThread[PRIIPCServerhandler7on60020](Running)
DaemonThread[PRIIPCServerhandler4on60020](Running)
DaemonThread[PRIIPCServerhandler2on60020](Running)
DaemonThread[PRIIPCServerhandler1on60020](Running)
DaemonThread[IPCServerhandler0on60020](Running)
DaemonThread[IPCServerhandler3on60020](Running)
DaemonThread[IPCServerhandler2on60020](Running)
DaemonThread[PRIIPCServerhandler0on60020](Running)
DaemonThread[PRIIPCServerhandler9on60020](Running)
DaemonThread[PRIIPCServerhandler5on60020](Running)
DaemonThread[PRIIPCServerhandler8on60020](Running)
DaemonThread[IPCServerhandler8on60020](Running)
DaemonThread[PRIIPCServerhandler6on60020](Running)
Thread[DestroyJavaVM](Running)