Trying to understand the capacity calculator

[John Smith <ja...@gmail.com>]

Hi, using the calculator spread sheet downloaded here:
https://apacheignite.readme.io/docs/capacity-planning

I have
10 000 000 objects
100 bytes average
0 backups

According to the calculator I need 2.7 GB and about 4.3GB of disk.
This includes the 30% indexes and the 100% in RAM calculations and native
persistence = true.

Lets assume single node deployment...

1- Does it mean that I need give or take 3GB of physical RAM on the host
and set OFF-HEAP value to 3GB?
2- And give or take 5GB of physical disk space and set the data region 5GB?
3- Now lets say I get 10 million and 1 objects would I get OOM?

Re: Trying to understand the capacity calculator

[John Smith <ja...@gmail.com>]

Thanks.

One last question.

If I set the off-heap to 3GB but I want to store more data then the
allowable heap size, that means I need to have set the disk persistence to
bigger file size correct?
And the heap will only contain the active/latest entries while the rest
will be on disk?

On Fri, 12 Apr 2019 at 20:10, aealexsandrov <ae...@gmail.com> wrote:

> Hi,
>
> This calculator provides the approximated results but I will try to
> explain:
>
> 1)Does it mean that I need to give or take 3GB of physical RAM on the host
> and set OFF-HEAP value to 3GB?
>
> Not fully correct. Yes, you should have 3GB of RAM for OFF-HEAP. But also
> you should provide some memory for Ignite application HEAP. The minimal
> requirement for a single node is 512 MB. It provides the possibility to
> start and works. Recommended configuration you can see here:
>
> https://apacheignite.readme.io/docs/jvm-and-system-tuning
>
> Also, your operating system and other application will use the memory. You
> should take it into account.
>
> 2)And give or take 5GB of physical disk space and set the data region 5GB?
>
> Correct in case if you will limit the WAL history. WAL history size could
> be
> unlimited in some configurations. It means that the size of it can't be
> calculated.
>
> You can set the limit:
>
> https://apacheignite.readme.io/docs/write-ahead-log#section-wal-archive
>
> 3)Now lets say I get 10 million and 1 objects would I get OOM?
>
> In case of persistence no. Some of the entries will be replaced by a new
> one
> in the memory but all of them will be stored on the disk. However, you can
> get "no disk space on device" error is there is no disk space.
>
> In case of disabled persistence the may see OOM in case if you didn't set
> the eviction policies:
>
> https://apacheignite.readme.io/docs/evictions
>
> BR,
> Andrei
>
>
>
> --
> Sent from: http://apache-ignite-users.70518.x6.nabble.com/
>

Re: Trying to understand the capacity calculator

[aealexsandrov <ae...@gmail.com>]

Hi,

This calculator provides the approximated results but I will try to explain:

1)Does it mean that I need to give or take 3GB of physical RAM on the host
and set OFF-HEAP value to 3GB?

Not fully correct. Yes, you should have 3GB of RAM for OFF-HEAP. But also
you should provide some memory for Ignite application HEAP. The minimal
requirement for a single node is 512 MB. It provides the possibility to
start and works. Recommended configuration you can see here:

https://apacheignite.readme.io/docs/jvm-and-system-tuning

Also, your operating system and other application will use the memory. You
should take it into account.

2)And give or take 5GB of physical disk space and set the data region 5GB?

Correct in case if you will limit the WAL history. WAL history size could be
unlimited in some configurations. It means that the size of it can't be
calculated.

You can set the limit:

https://apacheignite.readme.io/docs/write-ahead-log#section-wal-archive

3)Now lets say I get 10 million and 1 objects would I get OOM?

In case of persistence no. Some of the entries will be replaced by a new one
in the memory but all of them will be stored on the disk. However, you can
get "no disk space on device" error is there is no disk space.

In case of disabled persistence the may see OOM in case if you didn't set
the eviction policies:

https://apacheignite.readme.io/docs/evictions

BR,
Andrei



--
Sent from: http://apache-ignite-users.70518.x6.nabble.com/