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https://issues.apache.org/jira/browse/IGNITE-8841?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16759857#comment-16759857
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Ivan Pavlukhin edited comment on IGNITE-8841 at 2/4/19 1:48 PM:
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[~gvvinblade] please find my comments below.
# Can we get rid of {{MvccUtils.requestSnapshot}} as it mostly delegates to
{{GridNearTxLocal}}?
# I did not get why do we need to call {{PreviousQueries.init}} from
{{onLocalJoin}} callback? It worth adding a comment explaining the idea.
was (Author: pavlukhin):
[~gvvinblade] please find my comments below.
# Can we get rid of {{MvccUtils.requestSnapshot as it mostly delegates to
{{GridNearTxLocal}}?
# I did not get why do we need to call {{PreviousQueries.init}} from
{{onLocalJoin}} callback? It worth adding a comment explaining the idea.
> MVCC TX: Read transactions remap when coordinator fails.
> --------------------------------------------------------
>
> Key: IGNITE-8841
> URL: https://issues.apache.org/jira/browse/IGNITE-8841
> Project: Ignite
> Issue Type: Bug
> Components: mvcc, sql
> Reporter: Roman Kondakov
> Assignee: Igor Seliverstov
> Priority: Major
> Labels: failover
> Time Spent: 50m
> Remaining Estimate: 0h
>
> At the moment read transactions that don't acquire topology lock will be
> forcibly rolled back on topology change as read tx can be in fly while
> topology being change.
> This is done to prevent having active transaction with stale snapshots on
> new topology in cases of TX coordinator or Near node were lost.
>
> It would be nice to remap it somehow until they locked a topology or at least
> throw some meaningful exception to user.
> For example, it is possible to obtain a new "write" mvcc version from the
> new coordinator and use this version for all further writes while using "old"
> version for reads. In this case we need to change visibility rules a little:
> "old" version should see "own" updates made by "new" "write" version.
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