netty 连接 No buffer space available (maximum connections reached?): connect

active953
java.lang.IllegalStateException: failed to create a child event loop
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:99)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:68)
	at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:49)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:100)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:71)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:56)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:41)
	at com.bimatrix.revit.nettyTest.TcpClient.getBootstrap(TcpClient.java:35)
	at com.bimatrix.revit.nettyTest.TcpClient.run(TcpClient.java:97)
	at com.bimatrix.revit.controller.RevitController$1.run(RevitController.java:194)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: io.netty.channel.ChannelException: failed to open a new selector
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:126)
	at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:118)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:140)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:31)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:95)
	... 12 more
Caused by: java.io.IOException: Unable to establish loopback connection
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:125)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:69)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:141)
	at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50)
	at java.nio.channels.Pipe.open(Pipe.java:150)
	at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127)
	at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44)
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:124)
	... 16 more
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
	at sun.nio.ch.Net.connect0(Native Method)
	at sun.nio.ch.Net.connect(Net.java:465)
	at sun.nio.ch.Net.connect(Net.java:457)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:670)
	at java.nio.channels.SocketChannel.open(SocketChannel.java:184)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:97)
	... 24 more
java.lang.IllegalStateException: failed to create a child event loop
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:99)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:68)
	at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:49)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:100)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:71)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:56)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:41)
	at com.bimatrix.revit.nettyTest.TcpClient.getBootstrap(TcpClient.java:35)
	at com.bimatrix.revit.nettyTest.TcpClient.run(TcpClient.java:97)
	at com.bimatrix.revit.controller.RevitController$1.run(RevitController.java:194)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: io.netty.channel.ChannelException: failed to open a new selector
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:126)
	at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:118)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:140)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:31)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:95)
	... 12 more
Caused by: java.io.IOException: Unable to establish loopback connection
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:125)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:69)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:141)
	at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50)
	at java.nio.channels.Pipe.open(Pipe.java:150)
	at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127)
	at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44)
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:124)
	... 16 more
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
	at sun.nio.ch.Net.connect0(Native Method)
	at sun.nio.ch.Net.connect(Net.java:465)
	at sun.nio.ch.Net.connect(Net.java:457)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:670)
	at java.nio.channels.SocketChannel.open(SocketChannel.java:184)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:97)
	... 24 more
java.lang.IllegalStateException: failed to create a child event loop
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:99)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:68)
	at io.netty.channel.MultithreadEventLoopGroup.<init>(MultithreadEventLoopGroup.java:49)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:100)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:71)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:56)
	at io.netty.channel.nio.NioEventLoopGroup.<init>(NioEventLoopGroup.java:41)
	at com.bimatrix.revit.nettyTest.TcpClient.getBootstrap(TcpClient.java:35)
	at com.bimatrix.revit.nettyTest.TcpClient.run(TcpClient.java:97)
	at com.bimatrix.revit.controller.RevitController$1.run(RevitController.java:194)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:745)
Caused by: io.netty.channel.ChannelException: failed to open a new selector
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:126)
	at io.netty.channel.nio.NioEventLoop.<init>(NioEventLoop.java:118)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:140)
	at io.netty.channel.nio.NioEventLoopGroup.newChild(NioEventLoopGroup.java:31)
	at io.netty.util.concurrent.MultithreadEventExecutorGroup.<init>(MultithreadEventExecutorGroup.java:95)
	... 12 more
Caused by: java.io.IOException: Unable to establish loopback connection
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:125)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:69)
	at java.security.AccessController.doPrivileged(Native Method)
	at sun.nio.ch.PipeImpl.<init>(PipeImpl.java:141)
	at sun.nio.ch.SelectorProviderImpl.openPipe(SelectorProviderImpl.java:50)
	at java.nio.channels.Pipe.open(Pipe.java:150)
	at sun.nio.ch.WindowsSelectorImpl.<init>(WindowsSelectorImpl.java:127)
	at sun.nio.ch.WindowsSelectorProvider.openSelector(WindowsSelectorProvider.java:44)
	at io.netty.channel.nio.NioEventLoop.openSelector(NioEventLoop.java:124)
	... 16 more
Caused by: java.net.SocketException: No buffer space available (maximum connections reached?): connect
	at sun.nio.ch.Net.connect0(Native Method)
	at sun.nio.ch.Net.connect(Net.java:465)
	at sun.nio.ch.Net.connect(Net.java:457)
	at sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:670)
	at java.nio.channels.SocketChannel.open(SocketChannel.java:184)
	at sun.nio.ch.PipeImpl$Initializer.run(PipeImpl.java:97)
	... 24 more

 

socket连接数 不够

 

 

 

从上面的分析来看，导致出现 No buffer space available 这一问题的原因是多方面的，原因以及解决办法如下：

l 从代码层面上看， webservice 或 httpclient 调用未进行连接释放，导致资源无法回收 。

解决办法是在 axis2 的客户端代码中进行连接关闭，如下：

stub._getServiceClient().cleanupTransport();

stub._getServiceClient().cleanup();

stub.cleanup();

stub = null;

及时的关闭和clean 能有效的避免内存溢出的问题，及时回收资源。

或者 httpClient 中，最终要在 finally 调用 response.close()或者httpPost.releaseConnection() 进行连接释放。

l 从系统层面上看，系统 socket 连接数设置不合理， socket 连接数过小，易达到上限；其次是 2MSL 设置过长，容易积压 TIME_WAIT状态的 TCP 连接 。

解决办法是修改 Linux 内核参数，

修改系统 s ocket 最大连接数 ，在文件 /etc/security/limits.conf 最后加入下面两行：

* soft nofile 32768

* hard nofile 32768

或者缩小 2MSL 的时长、允许重用处于 TIME_WAIT状态的 TCP 连接、快速回收处于 TIME_WAIT状态的 TCP 连接，修改 /etc/sysctl.conf，添加如下几行：

# 改系統默认的 TIMEOUT 时间

net.ipv4.tcp_fin_timeout=2

# 启重用 ，允许将 TIME_WAIT sockets 重新用于新的 TCP 连接 默认为 0 表示关闭

net.ipv4.tcp_tw_reuse=1

# 开启 TCP 连接中 TIME_WAIT sockets 的快速回收 默认为 0  表示关闭

net.ipv4.tcp_tw_recycle=1

对于 windows 环境，可通过修改注册表进行配置：

\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

添加一个 DWORD 类型的值 TcpTimedWaitDelay ，值可以根据实际情况配置。

\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TCPIP\Parameters

添加一个 DWORD 类型的值 MaxUserPort ，值可以根据实际情况配置。

上面这些参数根据实际情况进行配置。

l 从LVS 层面上看，调度算法不合理，导致请求过多分配到某一台服务器上 。

解决办法，根据实际情况指定合理的负载均衡解决方案。

l 从安全层面上看，当服务器遭到DDoS（拒绝服务攻击）时，服务器大量积压TIME_WAIT状态的 TCP 连接而无法向外提供服务 。

解决办法，加强安全防护。

 

 

 

ps 我的问题解决是通过 修改windows注册表解决

注意是在Parameters 当前节点下面添加 参数 不要再子节点下面加