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https://issues.apache.org/jira/browse/HBASE-17931?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15971963#comment-15971963
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Duo Zhang commented on HBASE-17931:
-----------------------------------
Most issues under HBASE-17143 have the potential to break the compatibility of
old server and new client...
And the most dangerous one is HBASE-17508. We will use this feature when scan
meta.
Maybe we could do something on the implementation. We could return more results
then expected when scan, and the upper layer should just drop the needless
results. For now I believe there will be a fatal error if server does not
support limit as I added some asserts in the code...
Thanks.
> Rolling upgrade on branch-1 and master
> --------------------------------------
>
> Key: HBASE-17931
> URL: https://issues.apache.org/jira/browse/HBASE-17931
> Project: HBase
> Issue Type: Bug
> Components: scan
> Affects Versions: 1.4.0
> Reporter: Phil Yang
> Priority: Blocker
> Fix For: 2.0.0
>
>
> In branch-1 and master we have some improvement and new features on scanning
> which is not compatible.
> A client of old version to a server of new version is compatible (must be a
> bug if not, maybe need some test?).
> A client of new version may not be able to read from a server of old version
> correctly (because of scan limit, moreResults flag, etc), which is ok for
> major/minor upgrade and we can tell users to upgrade server before upgrading
> client. But RS also use scan to read meta. If meta table is in RS of old
> version, all RSs of new version may have trouble while scanning meta table.
> So we should make sure meta table always in servers of new version. Force
> meta table in Master and upgrade Master first, or assign meta table in region
> servers with latest version?
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