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https://issues.apache.org/jira/browse/IGNITE-6939?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladimir Ozerov updated IGNITE-6939:
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Labels: sql-stability (was: )
> Exclude false owners from the execution plan based on query response
> --------------------------------------------------------------------
>
> Key: IGNITE-6939
> URL: https://issues.apache.org/jira/browse/IGNITE-6939
> Project: Ignite
> Issue Type: Task
> Components: cache, sql
> Reporter: Alexey Goncharuk
> Priority: Major
> Labels: sql-stability
>
> This is related to IGNITE-6858, the fix in the ticket can be improved.
> The scenario leading to the issue is as follows:
> 1) Node A has partition 1 as owning
> 2) Node B has local partition map which has partition 1 on node A as owning
> 3) Topology change is triggered which would move partition 1 from A to
> another node, topology version is X
> 4) A transaction is started on node B on topology X
> 5) Partition is rebalanced and node A moves partition 1 to RENTING and then
> to EVICTED state, node A updates it's local partition map.
> 6) A new topology change is triggered
> 7) Node A sends partition map (transitively) to the node B, but since there
> is a pending exchange, node B ignores the updated map and still thinks that A
> owns partition 1 [1]
> 8) transaction attempts to execute an SQL query against partition 1 on node A
> and retries infinitely
> [1] The related code is in
> GridDhtPartitionTopologyImpl#update(AffinityTopologyVersion,
> GridDhtPartitionFullMap, CachePartitionFullCountersMap, Set,
> AffinityTopologyVersion)
> {code}
> if (stopping || !lastTopChangeVer.initialized() ||
> // Ignore message not-related to exchange if exchange is in progress.
> (exchangeVer == null && !lastTopChangeVer.equals(readyTopVer)))
> return false;
> {code}
> There are two possibilities to fix this:
> 1) Make all updates to partition map in a single thread, then we will not
> need update sequences and then we can update local partition map even when
> there is a pending exchange (this is a relatively big, but useful change)
> 2) Make a change in SQL query execution so that if a node cannot reserve a
> partition, do not map the partition to this node on the same topology version
> anymore (a quick fix)
> This will remove the need to throw an exception from SQL query inside
> transaction when there is a pending exchange.
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