[
https://issues.apache.org/jira/browse/HBASE-11742?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14102826#comment-14102826
]
Matteo Bertozzi commented on HBASE-11742:
-----------------------------------------
{quote}What happens if there is an older client library that wants to run a
MR-over snapshots job against snapshots dropped by newer servers? The older
library will be looking for table descriptors and snapshot region names in the
FS instead of SnapshotFileInfo/SnapshotRegionManifest.{quote}
you can't use old jars to read the new format.
{quote}Do we continue to handle TableSnapshotRegionSplit messages that have
RegionSpecifiers (field #1) instead of the new TableSchema and RegionInfo
fields (3 and 4)?{quote}
That proto is internal to the map reduce and used just for message passing, so
there is no need for compatibility there. Unless you have different jars
executing the mr job.
{quote}What happens if someone uses the newer client in a MR-over-snapshots job
where there is no SnapshotFileInfo/SnapshotRegionManifest data available
because the servers are older?{quote}
The new code is able to read the old format
{quote}What happens when we have a mix of snapshots dropped by an older server
side versus a newer server side?{quote}
The new code support taking snapshot during rolling upgrades, which means that
the older RS writes in the old format and the new one in the new format. Which
is fine since both format are readable and aggregated on read if necessary
(requires the new jars). If the master is already updates will do the merge of
the RS result converting to the single manifest if necessary.
> Backport HBASE-7987 and HBASE-11185 to 0.98
> -------------------------------------------
>
> Key: HBASE-11742
> URL: https://issues.apache.org/jira/browse/HBASE-11742
> Project: HBase
> Issue Type: Improvement
> Components: mapreduce, snapshots
> Affects Versions: 0.98.5
> Reporter: Esteban Gutierrez
> Assignee: Esteban Gutierrez
> Fix For: 0.98.6
>
> Attachments: HBASE-11742.v0.patch, HBASE-11742.v1.patch
>
>
> HBASE-7987 improves how snapshots are handled via a manifest file. This
> requires reverting HBASE-11360 since introduces an alternate functionality
> that is not compatible with HBASE-7987.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
