Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm
Precedence: bulk
Date: Sat, 7 Jan 2017 05:49:58 +0000 (UTC)
From: "stack (JIRA)" <jira@apache.org>
To: issues@hbase.apache.org
Message-ID: <JIRA.13032727.1483745358000.675938.1483768198556@Atlassian.JIRA>
In-Reply-To: <JIRA.13032727.1483745358000@Atlassian.JIRA>
References: <JIRA.13032727.1483745358000@Atlassian.JIRA> <JIRA.13032727.1483745358569@arcas>
Subject: [jira] [Commented] (HBASE-17437) Support specifying a WAL directory
 outside of the root directory
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
archived-at: Sat, 07 Jan 2017 05:50:00 -0000


    [ https://issues.apache.org/jira/browse/HBASE-17437?page=3Dcom.atlassia=
n.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D158=
06867#comment-15806867 ]=20

stack commented on HBASE-17437:
-------------------------------

[~yangyishan0901m] Thank you for your submission.

WAL dir gets same pegging as the root dir. Interesting. Could be helpful in=
 cases other than S3+EBS/EFS. We are working on redo of the fs layout but I=
'd think we could take this change in the meantime.

How amenable are you to feedback on the patch? Is it deployed by you lot al=
ready? If so, I'd imagine big changes would be tough?

Here is some quick feedback. More detail to follow.

Patch looks good.=20

You use 'hlog' when you talk of the WAL dir and attributes. Would be better=
 if you s/hlog/wal/g and s/LOG/WAL/g. e.g. s/getLogRootDir/getWALDir/g This=
 is a nit.

Thanks.


> Support specifying a WAL directory outside of the root directory
> ----------------------------------------------------------------
>
>                 Key: HBASE-17437
>                 URL: https://issues.apache.org/jira/browse/HBASE-17437
>             Project: HBase
>          Issue Type: Bug
>    Affects Versions: 1.2.4
>            Reporter: Yishan Yang
>              Labels: patch
>             Fix For: 2.0.0, 1.2.5
>
>         Attachments: hbase-17437-branch-1.2.patch, hbase-17437-master.pat=
ch
>
>
> Currently, the WAL and the StoreFiles need to be on the same FileSystem. =
Some FileSystems (such as Amazon S3) don=E2=80=99t support append or consis=
tent writes. These two properties are imperative for the WAL in order to av=
oid loss of writes. However, StoreFiles don=E2=80=99t necessarily need the =
same consistency guarantees (since writes are cached locally and if writes =
fail, they can always be replayed from the WAL).
> =20
> This JIRA aims to allow users to configure a log directory (for WALs) tha=
t is outside of the root directory or even in a different FileSystem. The d=
efault value will still put the log directory under the root directory.


--
This message was sent by Atlassian JIRA
(v6.3.4#6332)