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Konstantin Shvachko commented on HADOOP-1762: --------------------------------------------- Mostly cosmetic comments: # Datanode.setNewStorageID(): {code} } catch (UnknownHostException ignored) {} {code} Should not be ignored but rather logged. # We should deprecate FSEdits.OP_DATANODE_ADD and FSEdits.OP_DATANODE_REMOVE so that we could eventually remove them sometimes. # FSNamesystem.registerDatanode(): {code} NameNode.stateChangeLog.info( "BLOCK* NameSystem.registerDatanode: " + "node " + nodeS.getName() + " is replaced by " + nodeReg.getName() + " since they have the same storageID " + nodeReg.getStorageID() + ". If this message repeats, both nodes " + "might have same storageID by random " + "chance. You need to restart one of the " + "nodes with its data cleared. "); {code} This message may cause confusion in the regular case. The possibility of storage id collision is so negligible that we should not hint on it every time one node *_legally_* replaces another with the same storage id. Let's retain the original redaction. > Namenode does not need to store storageID and datanodeID persistently > --------------------------------------------------------------------- > > Key: HADOOP-1762 > URL: https://issues.apache.org/jira/browse/HADOOP-1762 > Project: Hadoop > Issue Type: Improvement > Components: dfs > Affects Versions: 0.14.0 > Reporter: Raghu Angadi > Assignee: Raghu Angadi > Attachments: HADOOP-1762-Opt2.patch, HADOOP-1762-Opt2.patch, > HADOOP-1762-Opt2.patch, HADOOP-1762-Opt2.patch, HADOOP-1762.patch > > > Currently Namenode stores all the storage-ids it generates since the > beginning (since last format). It allocates a new storageID everytime a new > datanode comes online. It also stores all the known datanode ids since the > beginning. > It would be better if Namenode did not have to keep track of these. I will > describe a proposal in the next comment. > This has implecations regd how Namenode helps administrators identify 'dead > datanodes' etc. These issues are addressed in HADOOP-1138. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.