[
https://issues.apache.org/jira/browse/HBASE-21098?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16605068#comment-16605068
]
Mingliang Liu commented on HBASE-21098:
---------------------------------------
Thanks [~mtylr]. I guess my suggestion is to compare FS using _scheme_,
_authority_, and _ugi_ instead of {{equals()}} to check if we can rename;
*and* if the comparison is false or FS.rename fails, we fallback to FS.copy.
But I'm fine with {{equals()}} as the copy itself is not costly. The reason we
can not rename without checking the feasibility is that, if the path
{{workingDir}} is not fully qualified URI (e.g. "/user/bob/snap") but is
actually on different FS (e.g. hdfs), the root FS.rename("/user/bob/snap",
"s3a://bucket/hbase/.snapshot/snap1") does not make sense but may still succeed.
Otherwise +1 (non-binding).
> Improve Snapshot Performance with Temporary Snapshot Directory when rootDir
> on S3
> ---------------------------------------------------------------------------------
>
> Key: HBASE-21098
> URL: https://issues.apache.org/jira/browse/HBASE-21098
> Project: HBase
> Issue Type: Improvement
> Affects Versions: 3.0.0, 1.4.8, 2.1.1
> Reporter: Tyler Mi
> Priority: Major
> Attachments: HBASE-21098.master.001.patch,
> HBASE-21098.master.002.patch, HBASE-21098.master.003.patch,
> HBASE-21098.master.004.patch, HBASE-21098.master.005.patch,
> HBASE-21098.master.006.patch, HBASE-21098.master.007.patch,
> HBASE-21098.master.008.patch, HBASE-21098.master.009.patch,
> HBASE-21098.master.010.patch, HBASE-21098.master.011.patch
>
>
> When using Apache HBase, the snapshot feature can be used to make a point in
> time recovery. To do this, HBase creates a manifest of all the files in all
> of the Regions so that those files can be referenced again when a user
> restores a snapshot. With HBase's S3 storage mode, developers can store their
> data off-cluster on Amazon S3. However, utilizing S3 as a file system is
> inefficient in some operations, namely renames. Most Hadoop ecosystem
> applications use an atomic rename as a method of committing data. However,
> with S3, a rename is a separate copy and then a delete of every file which is
> no longer atomic and, in fact, quite costly. In addition, puts and deletes on
> S3 have latency issues that traditional filesystems do not encounter when
> manipulating the region snapshots to consolidate into a single manifest. When
> HBase on S3 users have a significant amount of regions, puts, deletes, and
> renames (the final commit stage of the snapshot) become the bottleneck
> causing snapshots to take many minutes or even hours to complete.
> The purpose of this patch is to increase the overall performance of snapshots
> while utilizing HBase on S3 through the use of a temporary directory for the
> snapshots that exists on a traditional filesystem like HDFS to circumvent the
> bottlenecks.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
