CRITICAL nova [-] [Errno 32] Broken pipe

if i stop AMQP, the compute will dead.
it's essex rc1.

2012-03-25 21:40:55 INFO nova.rpc.common [-] Reconnecting to AMQP server on 192.168.28.5:5672
2012-03-25 21:41:00 ERROR nova.rpc.common [-] AMQP server on 192.168.28.5:5672 is unreachable: timed out. Trying again in 11 seconds.
(nova.rpc.common): TRACE: Traceback (most recent call last):
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/nova/rpc/impl_kombu.py", line 446, in reconnect
(nova.rpc.common): TRACE: self._connect()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/nova/rpc/impl_kombu.py", line 423, in _connect
(nova.rpc.common): TRACE: self.connection.connect()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/kombu/connection.py", line 118, in connect
(nova.rpc.common): TRACE: return self.connection
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/kombu/connection.py", line 438, in connection
(nova.rpc.common): TRACE: self._connection = self._establish_connection()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/kombu/connection.py", line 404, in _establish_connection
(nova.rpc.common): TRACE: conn = self.transport.establish_connection()
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/kombu/transport/pyamqplib.py", line 242, in establish_connection
(nova.rpc.common): TRACE: connect_timeout=conninfo.connect_timeout)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/kombu/transport/pyamqplib.py", line 51, in __init__
(nova.rpc.common): TRACE: super(Connection, self).__init__(*args, **kwargs)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/amqplib/client_0_8/connection.py", line 129, in __init__
(nova.rpc.common): TRACE: self.transport = create_transport(host, connect_timeout, ssl)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/amqplib/client_0_8/transport.py", line 281, in create_transport
(nova.rpc.common): TRACE: return TCPTransport(host, connect_timeout)
(nova.rpc.common): TRACE: File "/usr/lib/python2.7/site-packages/amqplib/client_0_8/transport.py", line 85, in __init__
(nova.rpc.common): TRACE: raise socket.error, msg
(nova.rpc.common): TRACE: timeout: timed out
(nova.rpc.common): TRACE:
2012-03-25 21:41:03 CRITICAL nova [-] [Errno 32] Broken pipe