[ https://issues.apache.org/jira/browse/HDFS-1094?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12855935#action_12855935 ]
Brian Bockelman commented on HDFS-1094: --------------------------------------- Hey Dhruba, How does this change the probability? Are you saying that P(rack r and rack r+1 fails) < P(rack i and rack j, i!=j) fails? Can you sketch out mathematically how this decreases the probability of failure? Brian > Intelligent block placement policy to decrease probability of block loss > ------------------------------------------------------------------------ > > Key: HDFS-1094 > URL: https://issues.apache.org/jira/browse/HDFS-1094 > Project: Hadoop HDFS > Issue Type: Improvement > Components: name-node > Reporter: dhruba borthakur > Assignee: dhruba borthakur > > The current HDFS implementation specifies that the first replica is local and > the other two replicas are on any two random nodes on a random remote rack. > This means that if any three datanodes die together, then there is a > non-trivial probability of losing at least one block in the cluster. This > JIRA is to discuss if there is a better algorithm that can lower probability > of losing a block. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: https://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira