Deprecate\remove REBALANCE_OBJECT_LOADED cache event

[Mmuzaf]

Igniters,


I've faced with EVT_CACHE_REBALANCE_OBJECT_LOADED [1] and
EVT_CACHE_REBALANCE_OBJECT_UNLOADED [2] cache events and not fully
understand their general purpose. Hope someone from the community can
clarify to me the initial idea of adding these events.

The first - it seems to me that these events are completely Ignite
internal thing. Why the user should be able to subscribe to such
events? (not related to tracking cache keys metrics). Once the data is
loaded to cache, I see no reasons to notifying the user about moving
cache keys from one node to another if the cluster topology changed.
It's up to Ignites mission to keep data consistency in any cases.

The second - I haven't found any real usages on GitHub\Google of these
events. Most of the examples are related to our community members and
Ignites documentation.

The third - Correct me if I am wrong, but subscribing for Ignites
events can have a strong influence on the cluster performance. So
fewer events available to users the better performance will be.


I think these events can be easily removed in the next 2.8 release.
WDYT? Am I missing something?

[1] https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_LOADED
[2] https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_UNLOADED

[Pavel Kovalenko]

Hello Maxim,

Thank you for researching this.
It seems those events can be used as an interceptor for the rebalance
process to make some extra actions after the entry is rebalanced.
However, I don't see any real usages despite tests. Most likely
functionality that used such rebalance events no longer exists.
I see no reasons to have it anymore.
+1 for removing in 2.8


ср, 31 июл. 2019 г. в 20:54, Maxim Muzafarov <[hidden email]>:

> Igniters,
>
>
> I've faced with EVT_CACHE_REBALANCE_OBJECT_LOADED [1] and
> EVT_CACHE_REBALANCE_OBJECT_UNLOADED [2] cache events and not fully
> understand their general purpose. Hope someone from the community can
> clarify to me the initial idea of adding these events.
>
> The first - it seems to me that these events are completely Ignite
> internal thing. Why the user should be able to subscribe to such
> events? (not related to tracking cache keys metrics). Once the data is
> loaded to cache, I see no reasons to notifying the user about moving
> cache keys from one node to another if the cluster topology changed.
> It's up to Ignites mission to keep data consistency in any cases.
>
> The second - I haven't found any real usages on GitHub\Google of these
> events. Most of the examples are related to our community members and
> Ignites documentation.
>
> The third - Correct me if I am wrong, but subscribing for Ignites
> events can have a strong influence on the cluster performance. So
> fewer events available to users the better performance will be.
>
>
> I think these events can be easily removed in the next 2.8 release.
> WDYT? Am I missing something?
>
> [1]
> https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_LOADED
> [2]
> https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_UNLOADED
>

[Mmuzaf]

Igniters,

I've created a ticket [1].

[1] https://issues.apache.org/jira/browse/IGNITE-12035

On Thu, 1 Aug 2019 at 10:55, Pavel Kovalenko <[hidden email]> wrote:

>
> Hello Maxim,
>
> Thank you for researching this.
> It seems those events can be used as an interceptor for the rebalance
> process to make some extra actions after the entry is rebalanced.
> However, I don't see any real usages despite tests. Most likely
> functionality that used such rebalance events no longer exists.
> I see no reasons to have it anymore.
> +1 for removing in 2.8
>
>
> ср, 31 июл. 2019 г. в 20:54, Maxim Muzafarov <[hidden email]>:
>
> > Igniters,
> >
> >
> > I've faced with EVT_CACHE_REBALANCE_OBJECT_LOADED [1] and
> > EVT_CACHE_REBALANCE_OBJECT_UNLOADED [2] cache events and not fully
> > understand their general purpose. Hope someone from the community can
> > clarify to me the initial idea of adding these events.
> >
> > The first - it seems to me that these events are completely Ignite
> > internal thing. Why the user should be able to subscribe to such
> > events? (not related to tracking cache keys metrics). Once the data is
> > loaded to cache, I see no reasons to notifying the user about moving
> > cache keys from one node to another if the cluster topology changed.
> > It's up to Ignites mission to keep data consistency in any cases.
> >
> > The second - I haven't found any real usages on GitHub\Google of these
> > events. Most of the examples are related to our community members and
> > Ignites documentation.
> >
> > The third - Correct me if I am wrong, but subscribing for Ignites
> > events can have a strong influence on the cluster performance. So
> > fewer events available to users the better performance will be.
> >
> >
> > I think these events can be easily removed in the next 2.8 release.
> > WDYT? Am I missing something?
> >
> > [1]
> > https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_LOADED
> > [2]
> > https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_UNLOADED
> >

[Anton Vinogradov-2]

+1 for removing, but...
Is it suitable to remove some API not at major release?

On Fri, Aug 2, 2019 at 11:32 AM Maxim Muzafarov <[hidden email]> wrote:

> Igniters,
>
> I've created a ticket [1].
>
> [1] https://issues.apache.org/jira/browse/IGNITE-12035
>
> On Thu, 1 Aug 2019 at 10:55, Pavel Kovalenko <[hidden email]> wrote:
> >
> > Hello Maxim,
> >
> > Thank you for researching this.
> > It seems those events can be used as an interceptor for the rebalance
> > process to make some extra actions after the entry is rebalanced.
> > However, I don't see any real usages despite tests. Most likely
> > functionality that used such rebalance events no longer exists.
> > I see no reasons to have it anymore.
> > +1 for removing in 2.8
> >
> >
> > ср, 31 июл. 2019 г. в 20:54, Maxim Muzafarov <[hidden email]>:
> >
> > > Igniters,
> > >
> > >
> > > I've faced with EVT_CACHE_REBALANCE_OBJECT_LOADED [1] and
> > > EVT_CACHE_REBALANCE_OBJECT_UNLOADED [2] cache events and not fully
> > > understand their general purpose. Hope someone from the community can
> > > clarify to me the initial idea of adding these events.
> > >
> > > The first - it seems to me that these events are completely Ignite
> > > internal thing. Why the user should be able to subscribe to such
> > > events? (not related to tracking cache keys metrics). Once the data is
> > > loaded to cache, I see no reasons to notifying the user about moving
> > > cache keys from one node to another if the cluster topology changed.
> > > It's up to Ignites mission to keep data consistency in any cases.
> > >
> > > The second - I haven't found any real usages on GitHub\Google of these
> > > events. Most of the examples are related to our community members and
> > > Ignites documentation.
> > >
> > > The third - Correct me if I am wrong, but subscribing for Ignites
> > > events can have a strong influence on the cluster performance. So
> > > fewer events available to users the better performance will be.
> > >
> > >
> > > I think these events can be easily removed in the next 2.8 release.
> > > WDYT? Am I missing something?
> > >
> > > [1]
> > >
> https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_LOADED
> > > [2]
> > >
> https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_UNLOADED
> > >
>

[Mmuzaf]

Anton,

I've thought that we will mark these events with @deprecated
annotation and remove all the internal usages. We can safely remove it
in 3.0 (see the issue [1] description).

[1] https://issues.apache.org/jira/browse/IGNITE-12035

On Tue, 13 Aug 2019 at 08:30, Anton Vinogradov <[hidden email]> wrote:

>
> +1 for removing, but...
> Is it suitable to remove some API not at major release?
>
> On Fri, Aug 2, 2019 at 11:32 AM Maxim Muzafarov <[hidden email]> wrote:
>
> > Igniters,
> >
> > I've created a ticket [1].
> >
> > [1] https://issues.apache.org/jira/browse/IGNITE-12035
> >
> > On Thu, 1 Aug 2019 at 10:55, Pavel Kovalenko <[hidden email]> wrote:
> > >
> > > Hello Maxim,
> > >
> > > Thank you for researching this.
> > > It seems those events can be used as an interceptor for the rebalance
> > > process to make some extra actions after the entry is rebalanced.
> > > However, I don't see any real usages despite tests. Most likely
> > > functionality that used such rebalance events no longer exists.
> > > I see no reasons to have it anymore.
> > > +1 for removing in 2.8
> > >
> > >
> > > ср, 31 июл. 2019 г. в 20:54, Maxim Muzafarov <[hidden email]>:
> > >
> > > > Igniters,
> > > >
> > > >
> > > > I've faced with EVT_CACHE_REBALANCE_OBJECT_LOADED [1] and
> > > > EVT_CACHE_REBALANCE_OBJECT_UNLOADED [2] cache events and not fully
> > > > understand their general purpose. Hope someone from the community can
> > > > clarify to me the initial idea of adding these events.
> > > >
> > > > The first - it seems to me that these events are completely Ignite
> > > > internal thing. Why the user should be able to subscribe to such
> > > > events? (not related to tracking cache keys metrics). Once the data is
> > > > loaded to cache, I see no reasons to notifying the user about moving
> > > > cache keys from one node to another if the cluster topology changed.
> > > > It's up to Ignites mission to keep data consistency in any cases.
> > > >
> > > > The second - I haven't found any real usages on GitHub\Google of these
> > > > events. Most of the examples are related to our community members and
> > > > Ignites documentation.
> > > >
> > > > The third - Correct me if I am wrong, but subscribing for Ignites
> > > > events can have a strong influence on the cluster performance. So
> > > > fewer events available to users the better performance will be.
> > > >
> > > >
> > > > I think these events can be easily removed in the next 2.8 release.
> > > > WDYT? Am I missing something?
> > > >
> > > > [1]
> > > >
> > https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_LOADED
> > > > [2]
> > > >
> > https://ignite.apache.org/releases/latest/javadoc/org/apache/ignite/events/EventType.html#EVT_CACHE_REBALANCE_OBJECT_UNLOADED
> > > >
> >