[ https://issues.apache.org/jira/browse/HDFS-3077?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13242697#comment-13242697 ]
Andrew Purtell commented on HDFS-3077: -------------------------------------- Re: JournalDaemons or Bookies on Datanodes (Slave nodes) vs "Master" nodes Makes sense. However, there will be many more Datanodes than metadata nodes, so finding new candidates to participate in a quorum protocol as others are lost or decommissioned would be less challenging given that larger pool. For each federated HDFS volume will we need 3 metadata nodes? > Quorum-based protocol for reading and writing edit logs > ------------------------------------------------------- > > Key: HDFS-3077 > URL: https://issues.apache.org/jira/browse/HDFS-3077 > Project: Hadoop HDFS > Issue Type: New Feature > Components: ha, name-node > Reporter: Todd Lipcon > Assignee: Todd Lipcon > > Currently, one of the weak points of the HA design is that it relies on > shared storage such as an NFS filer for the shared edit log. One alternative > that has been proposed is to depend on BookKeeper, a ZooKeeper subproject > which provides a highly available replicated edit log on commodity hardware. > This JIRA is to implement another alternative, based on a quorum commit > protocol, integrated more tightly in HDFS and with the requirements driven > only by HDFS's needs rather than more generic use cases. More details to > follow. -- 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