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https://issues.apache.org/jira/browse/IGNITE-20771?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vladislav Pyatkov reassigned IGNITE-20771:
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Assignee: Vladislav Pyatkov
> Implement tx coordinator liveness check
> ---------------------------------------
>
> Key: IGNITE-20771
> URL: https://issues.apache.org/jira/browse/IGNITE-20771
> Project: Ignite
> Issue Type: Improvement
> Reporter: Alexander Lapin
> Assignee: Vladislav Pyatkov
> Priority: Major
> Labels: ignite-3
>
> h3. Motivation
> In order to implement tx coordinator recovery, it's definitely required to
> understand whether coordinator is dead or not. Every data node has it's own
> txn state local volatile map (txId ->
> org.apache.ignite.internal.tx.TxStateMeta) where besides other fields we can
> find txCoordinatorId. Liveness check assumes that if a node with given id is
> available in physical topology then coordinator is alive, otherwise it's
> considered as dead. However despite the fact that such local check is fast
> enough there's no sense in checking it too often, espesially with subsequent
> sends of initialRecoveryRequests. Thus, it seems reasonable to add one more
> field to the TxStateMeta that will store last liveness check timestamp.
> Because it's always local checks it's valid to use System.currentTimeMillis
> or similar instead of HybridTimestamp in order to reduce the contention on
> the clock. Please pay attention that triggers that will initiate liveness
> checks will be implemented separetly.
> h3. Definition of Done
> * One more lastLivenessCheck timestamp is added to the TxStateMeta.
> * Aforementioned field is updated locally on each tx operation with
> currentTimeMillis.
> * New cluster-wide tx liveness interval configuration property is introduced.
> * Within liveness check
> ** if (the lastLivenessCheck >= currentTimeMillis - livenessInterval) - no-op
> ** else
> *** update lastLivenessCheck
> *** do the probe - check whether txCoordinatorId is still available in
> physical topology, if it's available no further actions are required if int's
> not then
> **** trigger initiateRecovery procedure implemented in IGNITE-20685.
> **** if commit partition is also unavailable (meaning that there's no
> primary replica) mark transaction as abandoned.
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