[
https://issues.apache.org/jira/browse/HBASE-2294?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12845711#action_12845711
]
Todd Lipcon commented on HBASE-2294:
------------------------------------
bq. Should we put it somewhere we can all hack on it? Up on hbase wiki or over
in public google doc?
I made a gist: http://gist.github.com/333664 - hopefully this is easy to hack
on and also retain edit history
Regarding the scan stuff, we should add some section to clarify "latest" with
regard to timestamp versus "latest" with regard to the time of the edit.
There's a lot of confusion over the semantics here - do timestamps just act
like a "z dimension" or do they actually impact consistent views, etc?
Will try to address your other feedback on the gist later this evening.
> Enumerate ACID properties of HBase in a well defined spec
> ---------------------------------------------------------
>
> Key: HBASE-2294
> URL: https://issues.apache.org/jira/browse/HBASE-2294
> Project: Hadoop HBase
> Issue Type: Task
> Components: documentation
> Reporter: Todd Lipcon
> Priority: Blocker
> Fix For: 0.20.4, 0.21.0
>
>
> It's not written down anywhere what the guarantees are for each operation in
> HBase with regard to the various ACID properties. I think the developers know
> the answers to these questions, but we need a clear spec for people building
> systems on top of HBase. Here are a few sample questions we should endeavor
> to answer:
> - For a multicell put within a CF, is the update made durable atomically?
> - For a put across CFs, is the update made durable atomically?
> - Can a read see a row that hasn't been sync()ed to the HLog?
> - What isolation do scanners have? Somewhere between snapshot isolation and
> no isolation?
> - After a client receives a "success" for a write operation, is that
> operation guaranteed to be visible to all other clients?
> etc
> I see this JIRA as having several points of discussion:
> - Evaluation of what the current state of affairs is
> - Evaluate whether we currently provide any guarantees that aren't useful to
> users of the system (perhaps we can drop in exchange for performance)
> - Evaluate whether we are missing any guarantees that would be useful to
> users of the system
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
