Incorrect fillFactor/memory usage metric

[coliin <co...@yahoo.co.uk.INVALID>]

Regarding the below issue, which causes incorrect memory consumption metric
in Ignite 2.7+ and related GG versions:

https://issues.apache.org/jira/browse/IGNITE-12096

As reported in the jira comment, this appears to be caused by failure to
account for pages that are flagged for reuse - the FreeList REUSE_BUCKET is
not counted when determining freeSpace.

Is anyone able to comment on whether there is a good reason for not doing
so? If there isn't then the issue is simple to fix.

Regards,
Colin.



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Re: Incorrect fillFactor/memory usage metric

[coliin <co...@yahoo.co.uk.INVALID>]

Thanks very much for your thoughts on this. I can confirm that the use of
getTotalUsedPages() does indeed allow us to calculate a memory consumption
metric that reduces as cache data is purged. I will comment on and close the
Jira ticket. This is great news.

Just one thought, in case there's any work in this area still under way -
perhaps it would be worth adding explicit methods on the metrics interface
to get used/free memory as per this calculation? It strikes me that these
metrics are absolutely critical for many use cases - but obtaining them is
not currently obvious or always reliable. I'm very happy for my test (see
jira) to be included in the test suite if that's useful?

Regards,
Colin.



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Re: Incorrect fillFactor/memory usage metric

[Alex Plehanov <pl...@gmail.com>]

Hello Colin,

AFAIK fill factor doesn't take into account reuse bucket by design, it's
not a bug.
To calculate memory consumption you can also use metric totalUsedPages
which take into account the reuse bucket (but doesn't take into account
free-list fill factor) This metric was introduced in Ignite 2.8 and hasn't
released yet.
.

вт, 14 янв. 2020 г. в 19:44, coliin <co...@yahoo.co.uk.invalid>:

> Regarding the below issue, which causes incorrect memory consumption metric
> in Ignite 2.7+ and related GG versions:
>
> https://issues.apache.org/jira/browse/IGNITE-12096
>
> As reported in the jira comment, this appears to be caused by failure to
> account for pages that are flagged for reuse - the FreeList REUSE_BUCKET is
> not counted when determining freeSpace.
>
> Is anyone able to comment on whether there is a good reason for not doing
> so? If there isn't then the issue is simple to fix.
>
> Regards,
> Colin.
>
>
>
> --
> Sent from: http://apache-ignite-developers.2346864.n4.nabble.com/
>