hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Lars Hofhansl (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-5229) Explore building blocks for "multi-row" local transactions.
Date Thu, 26 Jan 2012 04:25:40 GMT

    [ https://issues.apache.org/jira/browse/HBASE-5229?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13193551#comment-13193551
] 

Lars Hofhansl commented on HBASE-5229:
--------------------------------------

Is anybody interested in me exploring the split prefix idea described above?

Basically a table would declare a prefix of N bytes, and during splitting we make sure don't
split values with the same prefix (which essentially just means that we calculate the midKey
as we do now, and just take the first N bytes to perform the actual split, hence actual split
point would always be aligned with the prefixes).
That way we have defined a grouping of rows that could participate in local transactions.

                
> Explore building blocks for "multi-row" local transactions.
> -----------------------------------------------------------
>
>                 Key: HBASE-5229
>                 URL: https://issues.apache.org/jira/browse/HBASE-5229
>             Project: HBase
>          Issue Type: New Feature
>          Components: client, regionserver
>            Reporter: Lars Hofhansl
>            Assignee: Lars Hofhansl
>             Fix For: 0.94.0
>
>         Attachments: 5229-seekto-v2.txt, 5229-seekto.txt, 5229.txt
>
>
> HBase should provide basic building blocks for multi-row local transactions. Local means
that we do this by co-locating the data. Global (cross region) transactions are not discussed
here.
> After a bit of discussion two solutions have emerged:
> 1. Keep the row-key for determining grouping and location and allow efficient intra-row
scanning. A client application would then model tables as HBase-rows.
> 2. Define a prefix-length in HTableDescriptor that defines a grouping of rows. Regions
will then never be split inside a grouping prefix.
> #1 is true to the current storage paradigm of HBase.
> #2 is true to the current client side API.
> I will explore these two with sample patches here.
> --------------------
> Was:
> As discussed (at length) on the dev mailing list with the HBASE-3584 and HBASE-5203 committed,
supporting atomic cross row transactions within a region becomes simple.
> I am aware of the hesitation about the usefulness of this feature, but we have to start
somewhere.
> Let's use this jira for discussion, I'll attach a patch (with tests) momentarily to make
this concrete.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message