Hi, Pavel
This feature looks very interesting, can you add me as a reviewer please.
Or maybe I can contribute somehow?
Thanks,
Sergey.
On Tue, 18 Feb 2020 at 20:46, Pavel Tupitsyn <ptupit...@apache.org> wrote:
> Ilya, looks like there is a misunderstanding.
>
> We don't start near cache on a subset of server nodes. Let me explain
> again.
> Consider the following code, executed on any node (client or server - does
> not matter):
>
> ignite.createCache(new CacheConfiguration("c").setNearConfiguration(new
> NearCacheConfiguration()));
>
> As a result, cache "c" is started on all server nodes, and corresponding
> near cache is started on all server nodes,
> with the same config, eviction policy, and so on.
>
> Now, what do we do with .NET near cache in this situation?
> 1. Start .NET near cache as well on server nodes, always.
> 2. Introduce a config flag, and start .NET near cache only when the flag is
> set
>
> The problem with option (1) is that it changes the behavior of existing
> applications,
> increasing overhead for cache operations and increasing memory usage.
>
> As a user, I don't want some new features to be force-enabled on me
> silently in a new product version.
> That is why an opt-in config flag is required.
>
> Does this make sense?
>
> On Tue, Feb 18, 2020 at 6:42 PM Ilya Kasnacheev <ilya.kasnach...@gmail.com
> >
> wrote:
>
> > Hello!
> >
> > I'm not sure that we can/want to create near cache on a subset of server
> > nodes.
> >
> > If this is indeed possible, I would decouple that from .Net and introduce
> > as a separate feature.
> >
> > Ideally we should be able to start or stop near cache on any node, server
> > or client, and this should be the same cache for all platforms (including
> > Java). WDYT?
> >
> > Regards,
> > --
> > Ilya Kasnacheev
> >
> >
> > вт, 18 февр. 2020 г. в 17:31, Pavel Tupitsyn <ptupit...@apache.org>:
> >
> > > Ilya, as noted above:
> > >
> > > > There are 2 kinds of Near Caches:
> > > > - On client nodes: created per-node by calling ignite.CreateNearCache
> > > > - On server nodes: created on all server nodes if
> > > CacheConfiguration.NearCacheConfiguration is not null
> > > >
> > > > When user says ignite.CreateCache(new CacheConfiguration
> > > {NearCacheConfiguration = ...}),
> > > > the whole config is sent to all server nodes, and .NET-specific flag
> > has
> > > to be included somehow.
> > >
> > >
> > >
> > > On Tue, Feb 18, 2020 at 5:10 PM Ilya Kasnacheev <
> > ilya.kasnach...@gmail.com
> > > >
> > > wrote:
> > >
> > > > Hello!
> > > >
> > > > Why would it waste additional memory? All nodes are also Java nodes
> so
> > > they
> > > > will start near caches all right.
> > > >
> > > > Don't we have near cache start-up on per-node basis for clients,
> > anyway?
> > > >
> > > > I'm not convinced why we need this flag. I have to admit my
> > understanding
> > > > of near caches is limited.
> > > >
> > > > Regards,
> > > > --
> > > > Ilya Kasnacheev
> > > >
> > > >
> > > > вт, 18 февр. 2020 г. в 16:56, Pavel Tupitsyn <ptupit...@apache.org>:
> > > >
> > > > > Ilya, Aleksandr,
> > > > >
> > > > > The flag is called platformNearCacheEnabled, my idea is to have
> just
> > > one
> > > > > flag for all platforms.
> > > > >
> > > > > If some platform is present on the given node (.NET, C++) and it
> > > supports
> > > > > native near caching,
> > > > > then the flag is honored, otherwise it is ignored. We should not
> > throw
> > > > > exceptions,
> > > > > because mixed clusters are possible (.NET nodes along with Java
> > nodes).
> > > > >
> > > > > > Why would enabling it affect mixed`clusters?
> > > > > Initially the idea was to enable .NET near cache whenever
> > > > > NearCacheConfiguration is present.
> > > > > If we assume .NET-only clusters, it makes sense: existing code will
> > > work
> > > > > faster automatically.
> > > > >
> > > > > Mixed cluster is just one of the possible use cases when this may
> be
> > a
> > > > bad
> > > > > idea,
> > > > > e.g. users have enabled near caching to speed up their Java-based
> > > > > computations,
> > > > > and .NET nodes are used for something else, wasting memory on near
> > > > caching
> > > > > unnecessarily.
> > > > >
> > > > > On ue, Feb 18, 2020 at 4:30 PM Aleksandr Shapkin <
> lexw...@gmail.com
> > >
> > > > > wrote:
> > > > >
> > > > > > Pavel,
> > > > > >
> > > > > >
> > > > > >
> > > > > > I think it’s ok to add a new flag.
> > > > > >
> > > > > > Though we may change a name to something like
> > > > > #usePlatformCacheIfAvailable
> > > > > >
> > > > > >
> > > > > >
> > > > > > But it may vary depending on the implementation, i.e.
> > > > > >
> > > > > > should we throw an error if there is no native cache
> > > > > >
> > > > > > available for a platform or just ignore the configuration.
> > > > > >
> > > > > > вт, 18 февр. 2020 г. в 15:05, Pavel Tupitsyn <
> ptupit...@apache.org
> > >:
> > > > > >
> > > > > > > Igor,
> > > > > > >
> > > > > > > The problem is - we need to pass this flag around the
> cluster`for
> > > > > Server
> > > > > > > Near Caches,
> > > > > > > so that .NET near caches are started accordingly.
> > > > > > >
> > > > > > > There are 2 kinds of Near Caches:
> > > > > > > - On client nodes: created on every client node separately by
> > > calling
> > > > > > > ignite.CreateNearCache
> > > > > > > - On server nodes: created on all server nodes if
> > > > > > > CacheConfiguration.NearCacheConfiguration is set
> > > > > > >
> > > > > > > When user says ignite.CreateCache(new CacheConfiguration
> > > > > > > {NearCacheConfiguration = ...}),
> > > > > > > the whole config is sent 4o all server nodes, and .NET-specific
> > > flag
> > > > > has
> > > > > > to
> > > > > > > be included somehow.
> > > > > > >
> > > > > > > On Tue, Feb 18, 2020 at 2:59 PM Igor Sapego <
> isap...@apache.org>
> > > > > wrote:
> > > > > > >
> > > > > > > > Do you suggest to introduce it in general configuration? Why
> > not
> > > > > > > introduce
> > > > > > > > it only on platform side? Is there any .NET-specific
> > > configuration?
> > > > > > > >
> > > > > > > > Best Regards,
> > > > > > > > Igo2
> > > > > > > >
> > > > > > > >
> > > > > > > > On Tue, Feb 18, 2020 at 1:10 AM Pavel Tupitsyn <
> > > > ptupit...@apache.org
> > > > > >
> > > > > > > > wrote:
> > > > > > > >
> > > > > > > > > Igniters,
> > > > > > > > >
> > > > > > > > > I'm working on .NET Near Cache feature [1]
> > > > > > > > > (storing deserialized cache entries in CLR memory to
> improve
> > > > > > > > performance).
> > > > > > > > >
> > > > > > > > > Implementation is based on Java near cache, with some
> > callbacks
> > > > to
> > > > > > .NET
> > > > > > > > > side
> > > > > > > > > for updating and invalidating cached entries.
> > ~ > > > > > >
> > > > > > > > > However, I'd like to make this feature optional: enabling
> > Java
> > > > near
> > > > > > > cache
> > > > > > > > > should not
> > > > > > > > > always enable .NET near cache - some users may have mixed
> > > > clusters,
> > > > > > > etc.
> > > > > > > > >
> > > > > > > > > Therefore I'm adding
> > > > > NearCacheConfiguration#platformNearCacheEnabled
> > > > > > > > > boolean flag.
> > > > > > > > > Are there any objections or better ideas to configure this
> > > > > behavior?
> > > > > > > > >
> > > > > > > > > Thanks,
> > > > > > > > > Pavel
> > > > > > > > >
> > > > > > > > > [1] https://issues.apache.org/jira/browse/IGNITE-12691
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Alex.
> > > > > >
> > > > >
> > > >
> > >
> >
>
