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https://issues.apache.org/jira/browse/IGNITE-27435?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18047512#comment-18047512
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Alexey Scherbakov commented on IGNITE-27435:
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If we are on commit partition path, this means tx is abandoned (coordinator is
dead), so waiting doesn't make sense.
> Improve commit latency for explicit RW transactions
> ---------------------------------------------------
>
> Key: IGNITE-27435
> URL: https://issues.apache.org/jira/browse/IGNITE-27435
> Project: Ignite
> Issue Type: Improvement
> Reporter: Alexey Scherbakov
> Priority: Major
> Labels: ignite-3
> Fix For: 3.3
>
>
> Currently explicit transaction is committed as soon as all write inflights
> are completed.
> This adds additional latency before beginning to commit, caused by waiting
> (see TransactionInflights.ReadWriteTxContext#waitNoInflights).
> This can be optimized in the following way:
> 1. Each inflight addtitionally tracks corresponding key in the tx inflight
> context. A key is removed from the set as soon as inflight is replicated
> 2. We introduce addtitional persisted tx state: COMMITTING
> 3. The a tx is started to commit, it synchronously replicates COMMITTING
> state instead of COMMITED. Committing state additionally includes a list of
> keys (ack list), which are being inflight just before commit starts.
> 4. Tx commit as acked to the user as soon as COMMITTING state is replicated
> and all inflights are finished. This is "implicit commit".
> 5. As soon as tx is "implicitly committed", COMMITED state is replicated
> asynchronously. After this, tx is considered "explicitely committed".
> We need changes in write intent resolution logic.
> For coordinator path nothing is changed.
> For commit partition path, if the tx is in COMMITTING state, we need to
> attempt to resolve tx state by validating successful replication of all keys
> from the ack list. While resolving the state, the COMMITTED message can be
> received and processed accordingly.
> If multiple write intents are resolved concurrently, other are waiting for
> the first request outcome.
> Write intent remains unavailable until tx state is resolved.
> If inflight keys hit a hard limit (defined by some configuration parameter),
> this optimization is disabled.
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