[ http://issues.apache.org/jira/browse/HADOOP-227?page=comments#action_12458905 ] Konstantin Shvachko commented on HADOOP-227: --------------------------------------------
My idea of supporting multiple secondary nodes was that the primary node always deals with ONE secondary node, which in turn becomes the "primary" node for next secondary node, and so on. The order of the nodes is defined by how the secondary nodes are listed in the config file. That way each name-node need to know and speak to only one secondary, which substantially simplifies the logic. The primary decides when the new check point should be created and initiates the chain of checkpoints. I think we want to avoid heartbeat processing from secondary nodes and minimize inter-name-node communication traffic. I'd prefer to have all configuration in config file rather than configurable paths to other files, containing edditional configuration parameters. Don't like the last proposal linking "masters" in the config. This will make configration even more complicated. > Namespace check pointing is not performed until the namenode restarts. > ---------------------------------------------------------------------- > > Key: HADOOP-227 > URL: http://issues.apache.org/jira/browse/HADOOP-227 > Project: Hadoop > Issue Type: Bug > Components: dfs > Affects Versions: 0.2.0 > Reporter: Konstantin Shvachko > Assigned To: dhruba borthakur > Attachments: patch-async-checkpoints-0.9.0, > patch-async-checkpoints-0.9.0, patch-async-checkpoints-0.9.0 > > > In current implementation when the name node starts, it reads its image file, > then > the edits file, and then saves the updated image back into the image file. > The image file is never updated after that. > In order to provide the system reliability reliability the namespace > information should > be check pointed periodically, and the edits file should be kept relatively > small. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
