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From Vladimir Rodionov <vladrodio...@gmail.com>
Subject Re: Question in WALEdit
Date Wed, 22 Mar 2017 19:56:01 GMT
a) HBase does not support transaction - it only guarantees that single
mutation to a row-key is atomic. WALEdit can contains cells (mutations)
from different rows (for example when you do butchMutatate all operations
go to the same WALEdit afaik)
b) I coud not find postWALEdit()  in RegionObserver API. What coprocessor
hook did you mean exactly?


On Wed, Mar 22, 2017 at 5:19 AM, Sreeram <sreeram.v@gmail.com> wrote:

> Hi,
>  I have below questions on WALEdit. Looking forward to answer from the
> community.
>  a) I understand that all Cells in a given WALEdit form part of a single
> transaction. Since HBase atomicity is at row level, this implies all Cells
> in a given WALEdit have the same row key. is this understanding is correct
>  b) With MultiWAL, does log sequence monotonically increase based on
> transaction time stamp ?  Specifically, suppose there two transactions for
> two different tables for a single region server at times t0 and t1 (t0 <
> t1). In the presence of MultiWAL, will the postWALEdit() coprocessor event
> for transaction 0 be triggered before than transaction 1?
> Thanks,
> Sreeram
> PS: I use HBase version 1.2.0

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