When an HDFS client performs a write operation,it is recorded in the Primary NameNode’s edit log – The"edits"file" – The NameNode’s in memory representation of the file system metadata is also updated Then why do we need a separate edits log and a need to combine it with the snapshot of the fsimage later? Wouldn't the in memory representation which has the new edits as well, be the new fsimage? Unless I am missing some important fact here. Thanks! ... View more

I am writing a script that uses the following command:   hdfs haadmin getServiceState <serviceId>   What is the serviceId?   Thanks! ... View more