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From Dmitriy Pavlov <dpavlov....@gmail.com>
Subject Re: How much heap to allocate
Date Fri, 24 Aug 2018 11:03:45 GMT
Hi Eugene,

Misprint was corrected in https://issues.apache.org/jira/browse/IGNITE-7824 and
will be released as part of 2.7.

Even you don't have on-heap caches, entries during reading will be anyway
unmarshalled from off-heap to on-heap. So right choice of -Xmx has a high
dependence to particular application scenario.

Sincerely,
Dmitriy Pavlov

ср, 22 авг. 2018 г. в 21:30, eugene miretsky <eugene.miretsky@gmail.com>:

> Hi,
>
> I am getting the following warning when starting Ignite - "
>
> Nodes started on local machine require more than 20% of physical RAM what
> can lead to significant slowdown due to swapping
> "
>
> The 20% is a typo in version 2.5, it should be 80%.
>
> We have increased the max size of the default region to 70% of the
> available memory on the instance (since that's the only region we use at
> the moment).
>
> From reading the code
> <https://github.com/apache/ignite/blob/0681d8725d096272815dbd20c078871b27449895/modules/core/src/main/java/org/apache/ignite/internal/IgniteKernal.java>
that
> generates the error, it seems like
> 1) Ignite adds all the memory across all nodes to check if it is above the
> safeToUse threshold. I would expect the check to be done per node
> 2) totalOffheap seems to be the sum of the maxSizes of all regions, and
> totalHeap retrieved from the JVM configs. ingnite.sh sets  -Xmx200g.
>
> Assuming we are not enabling on-heap caching, what should we set the heap
> size to?
>
> Cheers,
> Eugene
>

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