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https://issues.apache.org/jira/browse/IGNITE-18026?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Vyacheslav Koptilin updated IGNITE-18026:
-----------------------------------------
Description:
*Motivation:*
As for now, HLC propagates via replica messages and Raft appendEntries
messages. The latter required changes in jraft code which was done under
IGNITE-17221 . Replica safe time (see IGNITE-17263 ) also uses HLC timestamps
coming from leader, but these timestamps should be applied only on commiting
index, so the whole mechanism consists of two steps: creating safe time
candidate on processing of appendEntries request, and appying it on index
commit.
All of this have grown up into significant amount of invasive code in jraft
which is not related to Raft protocol itself. It can be reworked by moving the
logic related to HLC and safe time propagation to ignite state machine listener
working on top of Raft.
*Definition of done:*
There is no code related to HLC and safe time left in ignite-raft module.
*Implementation notes:*
Raft write commands can be enriched with HybridTimestamps. Idle HLC adjustment
could be done using SafeTimeSyncCommand (it should be renamed in this case).
Safe time candidates will no longer be needed.
was:
*Motivation:*
As for now, HLC propagates via replica messages and Raft appendEntries
messages. The latter required changes in jraft code which was done under
IGNITE-17221 . Replica safe time (see IGNITE-17263 ) also uses HLC timestamps
coming from leader, but these timestamps should be applied only on commiting
index, so the whole mechanism consists of two steps: creating safe time
candidate on processing of appendEntries request, and appying it on index
commit.
All of this have grown up into significant amount of invasive code in jraft
which is not related to Raft protocol itself. It can be reworked by moving the
logic related to HLC and safe time propagation to ignite the state machine
listener working on top of Raft.
*Definition of done:*
There is no code related to HLC and safe time left in ignite-raft module.
*Implementation notes:*
Raft write commands can be enriched with HybridTimestamps. Idle HLC adjustment
could be done using SafeTimeSyncCommand (it should be renamed in this case).
Safe time candidates will no longer be needed.
> Rework HLC propagation in parts related to Raft
> -----------------------------------------------
>
> Key: IGNITE-18026
> URL: https://issues.apache.org/jira/browse/IGNITE-18026
> Project: Ignite
> Issue Type: Improvement
> Reporter: Denis Chudov
> Assignee: Denis Chudov
> Priority: Major
> Labels: ignite-3
> Fix For: 3.0.0-beta2
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> *Motivation:*
> As for now, HLC propagates via replica messages and Raft appendEntries
> messages. The latter required changes in jraft code which was done under
> IGNITE-17221 . Replica safe time (see IGNITE-17263 ) also uses HLC timestamps
> coming from leader, but these timestamps should be applied only on commiting
> index, so the whole mechanism consists of two steps: creating safe time
> candidate on processing of appendEntries request, and appying it on index
> commit.
> All of this have grown up into significant amount of invasive code in jraft
> which is not related to Raft protocol itself. It can be reworked by moving
> the logic related to HLC and safe time propagation to ignite state machine
> listener working on top of Raft.
> *Definition of done:*
> There is no code related to HLC and safe time left in ignite-raft module.
> *Implementation notes:*
> Raft write commands can be enriched with HybridTimestamps. Idle HLC
> adjustment could be done using SafeTimeSyncCommand (it should be renamed in
> this case). Safe time candidates will no longer be needed.
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