Issue 1:
由于安全问题, 需要关闭 dubbo telnet调试功能

Issue 2:
I have searched the issues of this repository and believe that this is not a duplicate.

I have checked the FAQ of this repository and believe that this is not a duplicate.

Environment

Dubbo version: 2.5.3

Operating System version: centos7

Java version: 1.8

Steps to reproduce this issue

所有配置都不调整，仅升级环境的jdk版本从1.7升级至1.8

2.qps压力为200左右，service rt 2ms

运行一段时间

Caused by: java.util.concurrent.RejectedExecutionException: Thread pool is EXHAUSTED! Thread Name: DubboServerHandler-10.27.70.208:18707, Pool Size: 200 (active: 200, core: 200, max: 200, largest: 200), Task: 323413 (completed: 323213), Executor status:(isShutdown:false, isTerminated:false, isTerminating:false), in dubbo://10.27.70.208:18707!

调整 threads="1000" dispatcher="message" 依然是运行一段时间会爆掉

Pls. provide [GitHub address] to reproduce this issue.

Expected Result

稳定运行

Actual Result

What actually happens?

If there is an exception, please attach the exception trace:

2019-08-30 10:16:59,071 WARN [org.jboss.netty.channel.DefaultChannelPipeline] [DUBBO] An exception was thrown by a user handler while handling an exception event ([id: 0xdea80c4e, /10.31.120.115:50188 :> /10.27.70.208:18707] EXCEPTION: com.alibaba.dubbo.remoting.ExecutionException: class com.alibaba.dubbo.remoting.transport.dispatcher.all.AllChannelHandler error when process disconnected event .), dubbo version: 2.5.3, current host: 127.0.0.1
com.alibaba.dubbo.remoting.ExecutionException: class com.alibaba.dubbo.remoting.transport.dispatcher.all.AllChannelHandler error when process caught event .
at com.alibaba.dubbo.remoting.transport.dispatcher.all.AllChannelHandler.caught(AllChannelHandler.java:67)
at com.alibaba.dubbo.remoting.transport.AbstractChannelHandlerDelegate.caught(AbstractChannelHandlerDelegate.java:44)
at com.alibaba.dubbo.remoting.transport.AbstractChannelHandlerDelegate.caught(AbstractChannelHandlerDelegate.java:44)
at com.alibaba.dubbo.remoting.transport.AbstractPeer.caught(AbstractPeer.java:127)
at com.alibaba.dubbo.remoting.transport.netty.NettyHandler.exceptionCaught(NettyHandler.java:112)
at com.alibaba.dubbo.remoting.transport.netty.NettyCodecAdapter$InternalDecoder.exceptionCaught(NettyCodecAdapter.java:165)
at org.jboss.netty.channel.Channels.fireExceptionCaught(Channels.java:525)
at org.jboss.netty.channel.AbstractChannelSink.exceptionCaught(AbstractChannelSink.java:48)
at org.jboss.netty.channel.Channels.fireChannelDisconnected(Channels.java:396)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.close(AbstractNioWorker.java:361)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:93)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:109)
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:312)
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:90)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.util.concurrent.RejectedExecutionException: Thread pool is EXHAUSTED! Thread Name: DubboServerHandler-10.27.70.208:18707, Pool Size: 200 (active: 200, core: 200, max: 200, largest: 200), Task: 323413 (completed: 323213), Executor status:(isShutdown:false, isTerminated:false, isTerminating:false), in dubbo://10.27.70.208:18707!
at com.alibaba.dubbo.common.threadpool.support.AbortPolicyWithReport.rejectedExecution(AbortPolicyWithReport.java:53)
at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:830)
at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1379)
at com.alibaba.dubbo.remoting.transport.dispatcher.all.AllChannelHandler.caught(AllChannelHandler.java:65)
... 17 more