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