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Posted to user@ignite.apache.org by Iv...@tdameritrade.com on 2021/01/28 21:49:27 UTC

PME and affinity guarantees

Dear Igniters,

Could someone please clarify if it is guaranteed that the Affinity (GridCacheAffinityImpl) will have the most up-to-date information about partitions distribution and the following scenario is impossible:


  1.  We have a registered listener of EVT_CACHE_REBALANCE_PART_LOADED and EVT_CACHE_REBALANCE_PART_UNLOADED events
  2.  We have a ContinuousQuery that keeps track of all the new cache entries (cluster-wide)
  3.  The events listener gets the Partition Loaded Event
  4.  The cache listener receives a new cache entry that belongs to the loaded partition and invokes Affinity#isPrimaryOrBackup(ignite.cluster().localNode(), key) and gets the FALSE response

In other words, is it guaranteed that the information about partitions distribution will be adjusted strictly before the first Partition Loaded Event will be distributed to listeners?

Best regards,
Ivan

Re: PME and affinity guarantees

Posted by Вячеслав Коптилин <sl...@gmail.com>.

Hello Ivan,

Well, EVT_CACHE_REBALANCE_PART_LOADED is triggered when the corresponding
partition is fully rebalanced and moved into the "OWNING" state,
and so, invoking Affinity#isPrimaryOrBackup(ignite.cluster().localNode(),
key) on this node should return "true".
to be more precise, this partition is treated as a "backup" until a new PME
(which is triggered by a Late Affinity Assignment) that can switch the
partition to "primary".

Thanks,
S.

пт, 29 янв. 2021 г. в 00:49, <Iv...@tdameritrade.com>:

> Dear Igniters,
>
> Could someone please clarify if it is guaranteed that the Affinity
> (GridCacheAffinityImpl) will have the most up-to-date information about
> partitions distribution and the following scenario is impossible:
>
>
>   1.  We have a registered listener of EVT_CACHE_REBALANCE_PART_LOADED and
> EVT_CACHE_REBALANCE_PART_UNLOADED events
>   2.  We have a ContinuousQuery that keeps track of all the new cache
> entries (cluster-wide)
>   3.  The events listener gets the Partition Loaded Event
>   4.  The cache listener receives a new cache entry that belongs to the
> loaded partition and invokes
> Affinity#isPrimaryOrBackup(ignite.cluster().localNode(), key) and gets the
> FALSE response
>
> In other words, is it guaranteed that the information about partitions
> distribution will be adjusted strictly before the first Partition Loaded
> Event will be distributed to listeners?
>
> Best regards,
> Ivan
>