Netty Heartbeat Detection Heartbeat (Fri)

HeartBeat Heartbeat

The necessity of heartbeat detection

1. Cluster heartbeat detection to avoid network interruption

2. Data synchronization: Master node write log, pull master node log from node every time.

The significance of heartbeat detection:

the client and the server have already established a long connection, the client opens the airplane mode, shuts down, shuts down the WiFi, the service side does not ( perceive ) receives the notification ( handremoved) and close the connection.

Core events:

usereventtriggered events for the Channelinboundhandleradapter class

Heartbeat detection Service-side code:

Server Startup class:

1  Public classHeartbeatserver {2 3      Public Static voidMain (string[] args)throwsinterruptedexception {4 5Eventloopgroup Bossgroup =NewNioeventloopgroup ();6Eventloopgroup Workergroup =NewNioeventloopgroup ();7 8         Try{9Serverbootstrap Serverbootstrap =Newserverbootstrap ();Ten Serverbootstrap.group (bossgroup,workergroup). OneChannel (Nioserversocketchannel.class) A. Handler (NewLogginghandler (loglevel.info)) -. Childhandler (NewMyheartbeatinitializer ()); -  theChannelfuture channelfuture = Serverbootstrap.bind (8899). sync (); - Channelfuture.channel (). Closefuture (). sync (); -}finally { - bossgroup.shutdowngracefully (); + workergroup.shutdowngracefully (); -         } +  A     } at  -}

Heartbeat Detection Initialization class:

1  Public classMyheartbeatinitializerextendsChannelinitializer<socketchannel> {2 @Override3     protected voidInitchannel (Socketchannel ch)throwsException {4 5Channelpipeline Channelpipeline =ch.pipeline ();6 7Channelpipeline.addlast (NewIdlestatehandler (3,7,10, Timeunit.seconds));8Channelpipeline.addlast (NewMyheartbeathandler ());9 Ten     } One}

Heartbeat detection Logic Processing handler:

1  Public classMyheartbeathandlerextendsChannelinboundhandleradapter {2 3 @Override4      Public voidUsereventtriggered (Channelhandlercontext ctx, Object evt)throwsException {5 6         if(evtinstanceofidlestateevent) {7Idlestateevent idlestateevent =(idlestateevent) evt;8 9String EventType =NULL;Ten  One             Switch(Idlestateevent.state ()) { A                  CaseReader_idle: -EventType = "Read Idle"; -                      Break; the                  CaseWriter_idle: -EventType = "Write Free"; -                      Break; -                  CaseAll_idle: +EventType = "Read and write Idle"; -                      Break; +  A             } at  -System.out.println (Ctx.channel (). Remoteaddress () + "Timeout event:" +eventtype); -  - Ctx.channel (). Close (); -         } -  in     } -}

Netty Heartbeat Detection Heartbeat (Fri)