[
https://issues.apache.org/jira/browse/HDFS-9814?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15147775#comment-15147775
]
Dinesh S. Atreya commented on HDFS-9814:
----------------------------------------
Having Block Level Leases functionality will make it easy to support
Transactions (Hive Transactions is planned in HIVE-9675).
HDFS Transactions JIRA will be created down the road.
> Advance Hadoop Architecture (AHA) - HDFS Block Level Leases (Locks)
> -------------------------------------------------------------------
>
> Key: HDFS-9814
> URL: https://issues.apache.org/jira/browse/HDFS-9814
> Project: Hadoop HDFS
> Issue Type: New Feature
> Reporter: Dinesh S. Atreya
>
> 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 message was sent by Atlassian JIRA
(v6.3.4#6332)
