RHN proxy fails to update clients and thorws "WARNING: Could not determine this machines public hostname".

Issue

• When running a yum update or yum install package on client machines. It fails with following errors:

Error: failed to retrieve repodata/ba2ebea83936003d9cebb120c2c7bc0afec8b8451ec9db6412d0f5071da6dc77-filelists.xml.gz from rhel-x86_64-server-6
       error was [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404"
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

• /var/log/squid/squid.out log

2012/10/08 17:44:35| WARNING: Could not determine this machines public hostname. Please configure one or set 'visible_hostname'.
2012/10/08 17:45:15| WARNING: Could not determine this machines public hostname. Please configure one or set 'visible_hostname'.
squid: ERROR: No running copy

• grep -i error /var/log/squid/squid.out

squid: ERROR: No running copy
squid: ERROR: Could not send signal 0 to process 14702: (3) No such process
squid: ERROR: Could not send signal 0 to process 6805: (3) No such process
squid: ERROR: Could not send signal 0 to process 12052: (3) No such process
squid: ERROR: Could not send signal 0 to process 13093: (3) No such process
squid: ERROR: Could not send signal 0 to process 20673: (3) No such process
squid: ERROR: Could not send signal 0 to process 12001: (3) No such process

• /var/log/rhn/rhn_proxy_broker.log

2013/04/23 03:27:25 +11:00 23096 172.23.36.72: proxy/rhnShared._connectToParent('ERROR', 'Error opening connection', 'http://satellite.example.com/XMLRPC/GET-REQ/rhel-x86_64-server-5/repodata/repomd.xml', error(111, 'Connection refused'))
2013/04/23 04:59:16 +11:00 23094 172.23.4.249: proxy/rhnShared._connectToParent('ERROR', 'Error opening connection', 'http://satellite.example.com/XMLRPC/GET-REQ/rhel-x86_64-server-6/repodata/repomd.xml', error(111, 'Connection refused'))

• RHN proxy server exception mail containing following exception error:

  #######
  
  Exception Handler Information
  
  Traceback (most recent call last):
  
  File "/usr/share/rhn/proxy/apacheServer.py", line 55, in __call__
     ret = f(req)
  File "/usr/share/rhn/proxy/apacheHandler.py", line 337, in handler
     ret = handlerObj.handler()
  File "/usr/share/rhn/proxy/broker/rhnBroker.py", line 156, in handler
     getResult = self.__local_GET_handler(self.req)
  File "/usr/share/rhn/proxy/broker/rhnBroker.py", line 323, in __local_GET_handler
     result = self.__callLocalRepository(reqchannel, reqaction, reqparams)
  File "/usr/share/rhn/proxy/broker/rhnBroker.py", line 423, in __callLocalRepository
     ret = apply(f, params)
  File "/usr/share/rhn/common/rhnRepository.py", line 102, in getPackage
     filePath = self.getPackagePath(pkg_spec)
  File "/usr/share/rhn/proxy/broker/rhnRepository.py", line 67, in getPackagePath
     self.__channelPackageMapping, ())
  File "/usr/share/rhn/proxy/broker/rhnRepository.py", line 165, in _cacheObj
     stringObject = dataProducer()
  File "/usr/share/rhn/proxy/broker/rhnRepository.py", line 198, in __channelPackageMapping
     self.channelVersion)
  File "/usr/share/rhn/proxy/broker/rhnRepository.py", line 228, in listPackages
     return function(channel, version)
  File "/usr/lib/python2.3/site-packages/rhn/rpclib.py", line 628, in __call__
     result = self._send(self._name, args)
  File "/usr/lib/python2.3/site-packages/rhn/rpclib.py", line 326, in _request
     self._handler, request, verbose=self._verbose)
  File "/usr/lib/python2.3/site-packages/rhn/transports.py", line 172, in request
     headers, fd = req.send_http(host, handler)
  File "/usr/lib/python2.3/site-packages/rhn/transports.py", line 700, in send_http
     self._connection.connect()
  File "/usr/lib/python2.3/site-packages/rhn/connections.py", line 159, in connect
     HTTPConnection.connect(self)
  File "/usr/lib/python2.3/httplib.py", line 548, in connect
     raise socket.error, msg
  error: (111, 'Connection refused')
  #######