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The "HdfsFutures" page has been changed by SanjayRadia. http://wiki.apache.org/hadoop/HdfsFutures?action=diff&rev1=8&rev2=9 -------------------------------------------------- * Read-only Replicas of NN * Scales performance but not namespace * Adds reliability and one of the steps towards HA - * Partition Namespace: Multiple namespace volumes + * Partition Namespace statically: Multiple namespace volumes * Scales both * Retains HDFS’s design philosophy but need a simplified automounter and management of horizontal scaling of NN servers + * A truly distributed name server that automatically partitions the namespace dynamically * Split function on NN (Namespace and Block maps) * scales name space x3, a little performance scaling * Page-in partial name space from disk (as in traditional FSs) @@ -118, +119 @@ Partition/distribute Name node (will also help performance) <<BR>>Several Options: - * Partition the namespace hierarchically and mount the volumes + * Statically Partition the namespace hierarchically and mount the volumes * In this scheme, there are multiple namespace volumes in a cluster. * All the name space volumes share the physical block storage (i.e. One storage pool) * Optionally All namespaces (ie volumes) are mounted at top level using an automounter like approach * A namepace can be explicitly mounted on to a node in another namename (a la mount in Posix) * Note the Cepf file system [ref] partitions automatically and mounts the partition - * Partition by a hash function - clients go to one NN by hashing the name + * A truly distributed name service that partitions the namespace dynamically. * Only keep part of the namespace in memory. * This like a tradional file system where the entire namepsace is stored in secondary and page-in as needed.
