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https://issues.apache.org/jira/browse/IGNITE-9314?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Ivan Pavlukhin updated IGNITE-9314:
-----------------------------------
Description:
Need to change DataStreamer semantics.
{{allowOverwrite=false}} mode currently is inconsistent with interval
_partition counters_ update approach used by MVCC transactions.
{{allowOverwrite=true}} mode is terribly slow when using single {{cache.put}}
operations (snapshot request, tx commit on coordinator overhead). Batched mode
using {{cache.putAll}} should handle write conflicts and possible deadlocks.
Also there is a problem when {{DataStreamer}} with {{allowOverwrite == false}}
does not insert value when versions for entry exist but they all are aborted.
Proper transactional semantics should developed for such case. After that
attention should be put on Cache.size method behavior. Cache.size addressed in
https://issues.apache.org/jira/browse/IGNITE-8149 could be decremented
improperly in
{{org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManager#mvccRemoveAll}}
method (called during streamer processing) when all existing mvcc row versions
are aborted or last committed one is _remove_ version.
was:
Need to change DataStreamer semantics (make it transactional)
Currently clients can see DataStreamer partial writes and two subsequent
selects, which are run in scope of one transaction at load time, may return
different results.
Related thread:
[http://apache-ignite-developers.2346864.n4.nabble.com/MVCC-and-IgniteDataStreamer-td32340.html]
Also there is a problem when {{DataStreamer}} with {{allowOverwrite == false}}
does not insert value when versions for entry exist but they all are aborted.
Proper transactional semantics should developed for such case. After that
attention should be put on Cache.size method behavior. Cache.size addressed in
https://issues.apache.org/jira/browse/IGNITE-8149 could be decremented
improperly in
{{org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManager#mvccRemoveAll}}
method (called during streamer processing) when all existing mvcc row versions
are aborted or last committed one is _remove_ version.
> MVCC TX: Datastreamer operations
> --------------------------------
>
> Key: IGNITE-9314
> URL: https://issues.apache.org/jira/browse/IGNITE-9314
> Project: Ignite
> Issue Type: Task
> Components: mvcc
> Reporter: Igor Seliverstov
> Assignee: Ivan Pavlukhin
> Priority: Major
> Fix For: 2.8
>
>
> Need to change DataStreamer semantics.
> {{allowOverwrite=false}} mode currently is inconsistent with interval
> _partition counters_ update approach used by MVCC transactions.
> {{allowOverwrite=true}} mode is terribly slow when using single {{cache.put}}
> operations (snapshot request, tx commit on coordinator overhead). Batched
> mode using {{cache.putAll}} should handle write conflicts and possible
> deadlocks.
> Also there is a problem when {{DataStreamer}} with {{allowOverwrite ==
> false}} does not insert value when versions for entry exist but they all are
> aborted. Proper transactional semantics should developed for such case. After
> that attention should be put on Cache.size method behavior. Cache.size
> addressed in https://issues.apache.org/jira/browse/IGNITE-8149 could be
> decremented improperly in
> {{org.apache.ignite.internal.processors.cache.IgniteCacheOffheapManager#mvccRemoveAll}}
> method (called during streamer processing) when all existing mvcc row
> versions are aborted or last committed one is _remove_ version.
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