Affects Version/s: 0.1.0
Fix Version/s: 0.2.0
currently, there's no way to analyze and debug DFS errors where blocks disapear.
name server should log its decisions that affect data, including block creation, removal, replication:
- block <b> created, assigned to datanodes A, B, ...
- datanode A dead, block <b> underreplicated(1), replicating to datanode C
- datanode B dead, block <b> underreplicated(2), replicating to datanode D
- datanode A alive, block <b> overreplicated, removing from datanode D
- block <removed> from datanodes C, D, ...
that will enable me to track down, two weeks later, a block that's missing from a file, and to debug the name server.
- rotate log file, as it might grow large
- make this behaviour optional/configurable