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The "ConnectionRefused" page has been changed by SteveLoughran: http://wiki.apache.org/hadoop/ConnectionRefused?action=diff&rev1=4&rev2=5 Comment: point at vendor, say don't file JIRAs = Connection Refused = - - You get a ConnectionRefused Exception when there is a machine at the address specified, but there is no program listening on the specific TCP port the client is using -and there is no firewall in the way silently dropping TCP connection requests. If you do not know what a TCP connection request is, please consult the [[http://www.ietf.org/rfc/rfc793.txt|specification]]. + You get a ConnectionRefused Exception when there is a machine at the address specified, but there is no program listening on the specific TCP port the client is using -and there is no firewall in the way silently dropping TCP connection requests. If you do not know what a TCP connection request is, please consult the [[http://www.ietf.org/rfc/rfc793.txt|specification]]. Unless there is a configuration error at either end, a common cause for this is the Hadoop service isn't running. + 1. Check the hostname the client using is correct 1. Check the IP address the client gets for the hostname is correct. 1. Check that there isn't an entry for your hostname mapped to 127.0.0.1 or 127.0.1.1 in /etc/hosts (Ubuntu is notorious for this) 1. Check the port the client is using matches that the server is offering a service on. 1. On the server, try a {{{telnet localhost <port>}}} to see if the port is open there. 1. On the client, try a {{{telnet <server> <port>}}} to see if the port is accessible remotely. - 1. Try connecting to the server/port from a different machine, to see if it just the single client misbehaving. + 1. Try connecting to the server/port from a different machine, to see if it just the single client misbehaving. + 1. If you are using a Hadoop-based product from a third party, including those from Cloudera, Hortonworks, Intel, EMC and others -please use the support channels provided by the vendor. + 1. Please do not file bug reports related to your problem, as it will be closed as [[http://wiki.apache.org/hadoop/InvalidJiraIssues|Invalid]] - None of these are Hadoop problems, they are host, network and firewall configuration issues. As it is your cluster, only you can find out and track down the problem. + None of these are Hadoop problems, they are host, network and firewall configuration issues. As it is your cluster, only you can find out and track down the problem.
