Shutting down netty 4 application throws RejectedExecutionException

问题:

let's assume the following pipeline:

pipeline.addLast(MY_STATELESS_DECODER); pipeline.addLast(SHARED_EVENT_EXECUTOR, MY_STATELESS_BUSINESS_LOGIC_HANDLER); 

I registered a ShutdownHook which shuts the NettyServer down like this:

boundChannel.close().await(5000); bossGroup.shutdownGracefully(0, 10, TimeUnit.SECONDS); workerGroup.shutdownGracefully(0, 10, TimeUnit.SECONDS); bossGroup.terminationFuture().awaitUninterruptibly(10, TimeUnit.SECONDS); workerGroup.terminationFuture().awaitUninterruptibly(10, TimeUnit.SECONDS); SHARED_EVENT_EXECUTOR.shutdownGracefully(0, 10, TimeUnit.SECONDS); SHARED_EVENT_EXECUTOR.terminationFuture().awaitUninterruptibly(10, TimeUnit.SECONDS); 

This however throws a RejectedExecutionException when I have connected clients:

java.util.concurrent.RejectedExecutionException: event executor terminated     at io.netty.util.concurrent.SingleThreadEventExecutor.reject(SingleThreadEventExecutor.java:703) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.SingleThreadEventExecutor.addTask(SingleThreadEventExecutor.java:296) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.SingleThreadEventExecutor.execute(SingleThreadEventExecutor.java:691) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.channel.DefaultChannelHandlerContext.teardown(DefaultChannelHandlerContext.java:91) ~[netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.channel.DefaultChannelHandlerContext.teardown0(DefaultChannelHandlerContext.java:106) ~[netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.channel.DefaultChannelHandlerContext.access$000(DefaultChannelHandlerContext.java:29) ~[netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.channel.DefaultChannelHandlerContext$1.run(DefaultChannelHandlerContext.java:94) ~[netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:325) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.SingleThreadEventExecutor.confirmShutdown(SingleThreadEventExecutor.java:613) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.DefaultEventExecutor.run(DefaultEventExecutor.java:40) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101) [netty-all-4.0.13.Final.jar:4.0.13.Final]     at java.lang.Thread.run(Thread.java:744) [na:1.7.0_45] 

The netty4 documentation according application-shutdown isn't helpful either. Do I have to follow a specific order to shutdown my application?

What I want to achieve is: 1. Stop accepting incoming messages 2. Handle all queued messages, which may involves sending messages

回答1:

When you call shutdown ,if there is any thread putting task into the taskQueue,and the taskQueue is not empty, it would call reject() method to reject your putting action.

文章来源: Shutting down netty 4 application throws RejectedExecutionException