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https://issues.apache.org/jira/browse/IGNITE-25286?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Roman Puchkovskiy updated IGNITE-25286:
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Description:
Currently, schema sync mechanism makes sure that AppliedMetastoreSafeTime
>=(operationTs - DD) for each operation (including KV operations and SQL).
AppliedMetastoreSafeTime is updated when the corresponding Metastore command is
both applied to the Metastore storage and all watch listeners fully handled the
revision corresponding to the command. Some watch listeners perform long
actions (like creating storages (this involves I/O) and starting replicas
(involves I/O and time to elect a leader); as a result, read/write/SQL
operations might be held by these long operations.
Schema sync mechanism actually only concerns Catalog updates (as the Catalog
stores schemas to sync on). Schemas are rarely updated. If we only concern safe
time of Catalog updates, long-running actions like storage creation and replica
starts will not affect transactional operations.
> Only concern Catalog updates application for Schema sync
> --------------------------------------------------------
>
> Key: IGNITE-25286
> URL: https://issues.apache.org/jira/browse/IGNITE-25286
> Project: Ignite
> Issue Type: Improvement
> Reporter: Roman Puchkovskiy
> Priority: Major
> Labels: ignite-3
>
> Currently, schema sync mechanism makes sure that AppliedMetastoreSafeTime
> >=(operationTs - DD) for each operation (including KV operations and SQL).
> AppliedMetastoreSafeTime is updated when the corresponding Metastore command
> is both applied to the Metastore storage and all watch listeners fully
> handled the revision corresponding to the command. Some watch listeners
> perform long actions (like creating storages (this involves I/O) and starting
> replicas (involves I/O and time to elect a leader); as a result,
> read/write/SQL operations might be held by these long operations.
> Schema sync mechanism actually only concerns Catalog updates (as the Catalog
> stores schemas to sync on). Schemas are rarely updated. If we only concern
> safe time of Catalog updates, long-running actions like storage creation and
> replica starts will not affect transactional operations.
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