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https://issues.apache.org/jira/browse/IGNITE-21112?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Kirill Tkalenko resolved IGNITE-21112.
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Resolution: Fixed
Implemented in IGNITE-21155.
> Mechanism to wait for completion of transactions started on schema versions
> preceding a target schema version
> -------------------------------------------------------------------------------------------------------------
>
> Key: IGNITE-21112
> URL: https://issues.apache.org/jira/browse/IGNITE-21112
> Project: Ignite
> Issue Type: Improvement
> Reporter: Roman Puchkovskiy
> Priority: Major
> Labels: ignite-3
> Fix For: 3.0.0-beta2
>
>
> A. Each node should handle the following message:
> RwTransactionsFinishedRequest; it will have targetSchemaVersion field of type
> int (which represents a Catalog version). The response will be
> RwTransactionsFinishedResponse containing the only field: finished (of type
> boolean).
> B. When the node gets such a request, it should (1) first check whether the
> target version has activated (not just appeared in the local Catalog) on the
> node. If not, (2) it should return false. If it has already been activated on
> the node, then the node should atomically query its TxManager whether it has
> any non-finished RW transactions that started on schema versions preceding
> the target version (this is determined by the beginTs of the transaction).
> C. To avoid a race between starting an RW transaction and checking for
> non-finished transactions, we need to start RW transactions in the following
> way:
> # beginTs = HLC.now()
> # {*}Without doing a schema sync{*}, find the Catalog version active at
> beginTs, assign it to TxCatalogVersion
> # Atomically wrt checking for transactions existence on schemas before X
> (see B.2), wrt finishing RW transactions and wrt raising the 'latest
> activated Catalog version' (used in B.1), add the new transaction with
> beginTs to the map of the currently active transactions (only if the 'latest
> activated Catalog version' is not higher than TxCatalogVersion)
> # If on item 3 it turned out that TxCatalogVersion is already lower than the
> 'latest activated Catalog version', goto step 1
> Note that, as on step 2 we don't do schema sync, resolving the catalog
> version corresponding to the beginTs might yield different results, so we
> might increment one counter and decrement another counter for the same
> transaction. To avoid this, we could resolve the 'catalog version for
> counter' just once (when incrementing) and store it (for instance, in
> TxStateMeta).
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