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From Andrey Mashenkov <andrey.mashen...@gmail.com>
Subject Re: Same Affinity For Same Key On All Caches
Date Tue, 28 Feb 2017 12:14:08 GMT
Hi Val,

Assume, we have A-B-A topology and we have X,Y caches of single partition
(just for simplicity)  with 1 backup and same afinity function.
Obviously, every node contains all partitions of both caches.
Now, we can have on nodeA:  X as primary and Y as backup
On nodeB: X as backup and Y as primary.

So, for same key data of both caches is collocated, but primary node

As far as I know, Rendezvous move partitions only to newly added node while
Fair can move partitions among all nodes.

It is possible I am wrong, but IHMO

It looks like partitions partition primary and backups creates in order and
do not reassign after exchange.
E.g. for topology A-B-C-D-A:
Newly created cache will have partition 'x' primary on A and backups on
B,C, partition 'y' primary on B and backups on C,D and etc.....
After adding node E, some primary will be moved to it and order will be
broken. E.g 'y' can become primary on E and backups on C,D.
Now if we add new cache, we wil have for 'y' C as primary and D,E as backup.

Possible we just have wrong node order in partition->node mapping.

Can somebody clarify how primary partition is assigned?

On Tue, Feb 28, 2017 at 9:56 AM, Alper Tekinalp <alper@evam.com> wrote:

> Hi Val,
> We are using fair affinity function because we want to keep data more
> balanced among nodes. When I change "new FairAffinityFunction(128)"  with
> "new RendezvousAffinityFunction(false, 128)" I could not reproduce the
> problem.
> On Tue, Feb 28, 2017 at 7:15 AM, vkulichenko <
> valentin.kulichenko@gmail.com> wrote:
>> Andrey,
>> Is there an explanation for this? If this all is true, it sounds like a
>> bug
>> to me, and pretty serious one.
>> Alper, what is the reason for using fair affinity function? Do you have
>> the
>> same behavior with rendezvous (the default one)?
>> -Val
>> --
>> View this message in context: http://apache-ignite-users.705
>> 18.x6.nabble.com/Same-Affinity-For-Same-Key-On-All-Caches-
>> tp10829p10933.html
>> Sent from the Apache Ignite Users mailing list archive at Nabble.com.
> --
> Alper Tekinalp
> Software Developer
> Evam Streaming Analytics
> Atatürk Mah. Turgut Özal Bulv.
> Gardenya 5 Plaza K:6 Ataşehir
> 34758 İSTANBUL
> Tel:  +90 216 455 01 53 Fax: +90 216 455 01 54
> www.evam.com.tr
> <http://www.evam.com>

Best regards,
Andrey V. Mashenkov

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