Provide a command line entry point to view/test topology options ----------------------------------------------------------------
Key: HADOOP-8232 URL: https://issues.apache.org/jira/browse/HADOOP-8232 Project: Hadoop Common Issue Type: Sub-task Components: util Affects Versions: 0.23.1 Reporter: Steve Loughran Priority: Minor Add a new command line entry point "topo" with commands for preflight checking of a clusters topology setup. The initial operations would be to list the implementation class of the mapper, and attempt to load it, resolve a set of supplied hostnames, then dump the topology map after the resolution process. Target audience: # ops teams trying to get a new/changed script working before deploying it on a cluster. # someone trying to write their first script. Resolve and list the rack mappings of the given host {code} hadoop topo test [host1] [host2] ... {code} This would load the hostnames from a given file, resolve all of them and list the results: {code} hadoop topo testfile filename {code} This version is intended for the ops team who have a list of hostnames, IP addresses. * Rather than just list them, the ops team may want to mandate that there were no /default-rack mappings found, as that is invariably a sign that the script isn't handling a hostname properly. * No attempt to be clever and do IP address resolution, FQDN to hostname mapping, etc. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira