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https://issues.apache.org/jira/browse/IGNITE-17735?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17607891#comment-17607891
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Vladimir Steshin edited comment on IGNITE-17735 at 10/18/22 4:33 PM:
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Datastreamer with Individual receiver and ATOMIC/PRIMARY_SYNC persistent cache 
may consume heap. It has related 'perNodeParallelOperations()' setting. But it 
doesn't depend on StreamReceiver. User can experience heap issues with a 
trivial case.

The problem is that the streamer doesn't wait for backup updates on primary 
node and keep sending update batches again and again. Individual receiver uses 
cache.put(). Every put creates a future for primary update and future and 
update update request for the backups. Nodes start accumulating related  to 
single update objects in the heap (`processDhtAtomicUpdateRequest()`).

There is no reason to send more than 2-3-4 unresponded batches because they 
stuck at disk writes, WAL writes, page replacements, WAL rolling, GCs and so 
on. Why so many parallel batches by default? Especially for persistent caches. 
IgniteDataStreamer.DFLT_PARALLEL_OPS_MULTIPLIER=8 is weird to me. With 8 CPUs 
and 16 threads I get 128 parallel batches. 

Proposal: reduce default max parallel batches for a nod. Make this value depend 
on the persistence.

Some JFR screens attached.

See `JmhStreamerReceiverBenchmark.bchIndividual_512_1()`, 
`DataStreamProcessorSelfTest.testAtomicPrimarySyncStability()`.


was (Author: vladsz83):
Datastreamer with Individual receiver and ATOMIC/PRIMARY_SYNC persistent cache 
may consume heap. The test case is simple: 2 or 3 servers, 2 or 1 backups and 
Datastreamer from client loading significant amount of data. Around 1G of heap. 
Tested with 6 (16) CPU's, 6-16 streamer threads.

See `JmhStreamerReceiverBenchmark.bchIndividual_512_1()`, 
`DataStreamProcessorSelfTest.testAtomicPrimarySyncStability()`.

The problem is that the streamer doesn't wait for backup updates on primary 
node and keep sending update batches again and again. Individual receiver uses 
cache.put(). Every put creates a future for primary update and future and 
update update request for the backups. Nodes start accumulating related  to 
single update objects in the heap (`processDhtAtomicUpdateRequest()`).

There is no reason to send more than 2-3-4 unresponded batches because they 
stuck at disk writes, WAL writes, page replacements, WAL rolling, GCs and so 
on. Why so many parallel batches by default? Especially for persistent caches. 
IgniteDataStreamer.DFLT_PARALLEL_OPS_MULTIPLIER=8 is weird to me. With 8 CPUs 
and 16 threads I get 128 parallel batches. 

Solution: reduce default max parallel batches for a nod. Make this value depend 
on the persistence.

Some JFR screens attached.

> Datastreamer may consume heap with default settings.
> ----------------------------------------------------
>
>                 Key: IGNITE-17735
>                 URL: https://issues.apache.org/jira/browse/IGNITE-17735
>             Project: Ignite
>          Issue Type: Sub-task
>            Reporter: Vladimir Steshin
>            Assignee: Vladimir Steshin
>            Priority: Major
>              Labels: ise
>         Attachments: DS_heap_no_events_no_wal.png, 
> DS_heap_no_events_no_wal_2.png
>
>          Time Spent: 40m
>  Remaining Estimate: 0h
>




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