Nodes started on local machine require more than 80% of physical RAM

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Stéphane Thibaud Stéphane Thibaud
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Nodes started on local machine require more than 80% of physical RAM

Hello!

I am deploying my first Ignite node, but I encountered the following message
on start:

[07:42:50] Nodes started on local machine require more than 80% of physical
RAM what can lead to significant slowdown due to swapping (please decrease
JVM heap size, data region size or checkpoint buffer size) [required=950MB,
available=1692MB]

I did apply the followings tweaks to the Java VM -Xms512m and Xmx512m and it
had an effect in that the 'required' part in the message above went down.
However, required/available < 0.8 now and I don't know why the message still
appears. Any ideas?


Kind regards,

Stéphane



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dmagda dmagda
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Re: Nodes started on local machine require more than 80% of physical RAM

Hi Stéphane,

This message relates to Ignite off-heap memory. You need to adjust the size for its data regions. Hope this page helps:

-
Denis


On Wed, Feb 12, 2020 at 12:07 AM Stéphane Thibaud <[hidden email]> wrote:
Hello!

I am deploying my first Ignite node, but I encountered the following message
on start:

[07:42:50] Nodes started on local machine require more than 80% of physical
RAM what can lead to significant slowdown due to swapping (please decrease
JVM heap size, data region size or checkpoint buffer size) [required=950MB,
available=1692MB]

I did apply the followings tweaks to the Java VM -Xms512m and Xmx512m and it
had an effect in that the 'required' part in the message above went down.
However, required/available < 0.8 now and I don't know why the message still
appears. Any ideas?


Kind regards,

Stéphane



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Sent from: http://apache-ignite-users.70518.x6.nabble.com/
Mikhail Mikhail
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Re: Nodes started on local machine require more than 80% of physical RAM

In reply to this post by Stéphane Thibaud
Hi Stephane,

Ignite has a check: it sums all JVM heaps and off-heap sizes for all nodes
in the cluster that you run on the same host,  and check if it takes more
then 80% of host RAM OR *there's less then 4GB left*:

https://github.com/apache/ignite/blob/ef6764e99c318a857ec92d6a270d8ef621cfde66/modules/core/src/main/java/org/apache/ignite/internal/IgniteKernal.java#L1753

So your system just have only 1.5GB, so you always will see this message,
while "required" size less than "available" and there's still some space for
OS and your tools you can ignore this message. Plus, even if you will
require more space then your RAM capacity, I believe you use SWAP, don't
you? so it's still okay to run Ignite, but please, remember that you can
have poor performance due to lack of RAM.

Thanks,
Mike.



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Stéphane Thibaud Stéphane Thibaud
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Re: Nodes started on local machine require more than 80% of physical RAM

Thank you. I am running this on a Google Cloud instance with Container OS and was trying to find a minimal setup first. Maybe I need to add some more RAM to the instance, but 4GB for container OS seems a bit much. Thanks for letting me know in any case! :-)


Kind regards,

Stéphane

2020年2月13日(木) 7:55 Mikhail <[hidden email]>:
Hi Stephane,

Ignite has a check: it sums all JVM heaps and off-heap sizes for all nodes
in the cluster that you run on the same host,  and check if it takes more
then 80% of host RAM OR *there's less then 4GB left*:

https://github.com/apache/ignite/blob/ef6764e99c318a857ec92d6a270d8ef621cfde66/modules/core/src/main/java/org/apache/ignite/internal/IgniteKernal.java#L1753

So your system just have only 1.5GB, so you always will see this message,
while "required" size less than "available" and there's still some space for
OS and your tools you can ignore this message. Plus, even if you will
require more space then your RAM capacity, I believe you use SWAP, don't
you? so it's still okay to run Ignite, but please, remember that you can
have poor performance due to lack of RAM.

Thanks,
Mike.



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Mikhail Mikhail
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Re: Nodes started on local machine require more than 80% of physical RAM

> but 4GB for container OS seems a bit much. Thanks for letting me know in
any case!

Absolutely agree with you that 4GB is too much, especially for the container
environment.
I think the person who wrote the check thought about big bare-metal
installations with 128GB+ RAM, but you can just ignore this warning, as I
said, just make sure that required mem < total mem.

Thanks,
Mike.



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