[ https://issues.apache.org/jira/browse/HDFS-4521?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13701514#comment-13701514 ]
Matt Foley commented on HDFS-4521: ---------------------------------- Aaron or Suresh, could you please review? > invalid network topologies should not be cached > ----------------------------------------------- > > Key: HDFS-4521 > URL: https://issues.apache.org/jira/browse/HDFS-4521 > Project: Hadoop HDFS > Issue Type: Improvement > Affects Versions: 2.1.0-beta, 1.3.0 > Reporter: Colin Patrick McCabe > Assignee: Junping Du > Priority: Minor > Fix For: 2.1.0-beta > > Attachments: HDFS-4521.001.patch, HDFS-4521.002.patch, > HDFS-4521.005.patch, HDFS-4521.006.patch, HDFS-4521.008.patch, > HDFS-4521-branch1.patch > > > When the network topology is invalid, the DataNode refuses to start with a > message such as this: > {quote} > org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol.registerDatanode from > 172.29.122.23:55886: error: > org.apache.hadoop.net.NetworkTopology$InvalidTopologyException: Invalid > network topology. You cannot have a rack and a non-rack node at the same > level of the network topology. > {quote} > This is expected if you specify a topology file or script which puts leaf > nodes at two different depths. However, one problem we have now is that this > incorrect topology is cached forever. Once the NameNode sees it, this > DataNode can never be added to the cluster, since this exception will be > rethrown each time. The NameNode will not check to see if the topology file > or script has changed. We should clear the topology mappings when there is > an InvalidTopologyException, to prevent this problem. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira