Client mqttbench1b81e-19960 has exceeded timeout, disconnecting [IO wait]

[liwenxian]

excute：
mqtt-bench -action=p -broker="tcp://27.0.0.1:1883" -clients=20000 -count=10

goroutine 1761 [IO wait]:
net.runtime_pollWait(0x7f376441bc80, 0x72, 0xc8200820e0)
/usr/lib/golang/src/runtime/netpoll.go:157 +0x60
net.(_pollDesc).Wait(0xc820909a30, 0x72, 0x0, 0x0)
/usr/lib/golang/src/net/fd_poll_runtime.go:73 +0x3a
net.(_pollDesc).WaitRead(0xc820909a30, 0x0, 0x0)
/usr/lib/golang/src/net/fd_poll_runtime.go:78 +0x36
net.(_netFD).Read(0xc8209099d0, 0xc820ce6750, 0x1, 0x1, 0x0, 0x7f37658d9140, 0xc8200820e0)
/usr/lib/golang/src/net/fd_unix.go:232 +0x23a
net.(_conn).Read(0xc82014c380, 0xc820ce6750, 0x1, 0x1, 0x0, 0x0, 0x0)
/usr/lib/golang/src/net/net.go:172 +0xe4
io.ReadAtLeast(0x7f376771c050, 0xc82014c380, 0xc820ce6750, 0x1, 0x1, 0x1, 0x0, 0x0, 0x0)
/usr/lib/golang/src/io/io.go:298 +0xe6
io.ReadFull(0x7f376771c050, 0xc82014c380, 0xc820ce6750, 0x1, 0x1, 0x1, 0x0, 0x0)
/usr/lib/golang/src/io/io.go:316 +0x62
git.eclipse.org/gitroot/paho/org.eclipse.paho.mqtt.golang.git/packets.ReadPacket(0x7f376771c050, 0xc82014c380, 0x0, 0x0, 0x0, 0x0)
/data/go/src/git.eclipse.org/gitroot/paho/org.eclipse.paho.mqtt.golang.git/packets/packets.go:105 +0xd4
git.eclipse.org/gitroot/paho/org%2eeclipse%2epaho%2emqtt%2egolang%2egit.incoming(0xc820cacc00)
/data/go/src/git.eclipse.org/gitroot/paho/org.eclipse.paho.mqtt.golang.git/net.go:78 +0x263
created by git.eclipse.org/gitroot/paho/org%2eeclipse%2epaho%2emqtt%2egolang%2egit.(*Client).Connect.func1
/data/go/src/git.eclipse.org/gitroot/paho/org.eclipse.paho.mqtt.golang.git/client.go:254 +0x14a4

1476173392: Client mqttbench1b81e-19960 has exceeded timeout, disconnecting.
1476173392: Socket error on client mqttbench1b81e-19960, disconnecting.