Advance Hybrid Cloud Architecture (AHA) - HDFS Block Level Leases (Locks)

Link to Umbrella JIRA https://issues.apache.org/jira/browse/HADOOP-12620
See https://issues.apache.org/jira/browse/HADOOP-12620?focusedCommentId=15046300&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15046300 for more details.

Currently, only file level leases (locks) are supported. This JIRA is for expanding the capability to allow block level leases (locks).

Block level leases presume that Block Manager as a Service (reference JIRA https://issues.apache.org/jira/browse/HDFS-5477) solution is available.

File level leases are default. When block level leases are requested, they will supersede file level leases and lease (lock) capability will advance to block levels. In the absence of block level leases, leases degenerate into file level leases.

If we correspond to DBMS paradigm, file level leases amount to table locks; while row level locks are not possible with HDFS, the closest we can get to is block level leases (locks).

This JIRA is within the broad initiative:

Advance Hadoop Architecture (AHA) / Advance Hadoop Adaptabilities (AHA) /

Advance Hybrid Cloud Architecture (AHA)