Compute API requires code deployment, which may be an obstacle in some
cases.
But instead of withAffinityNode, I think we can add a new method to
IgniteClient:
public ClientTransactions transactions(ClusterGroup grp);
Similar to existing compute(ClusterGroup) and services(ClusterGroup)
methods.
On Thu, Aug 11, 2022 at 7:31 PM Alexei Scherbakov <
alexey.scherbak...@gmail.com> wrote:
> Moving transaction logic to the client seems to me a bad idea.
>
> I would instead send the transaction's code close to data using Compute
> API.
>
> чт, 11 авг. 2022 г. в 17:54, Maxim Muzafarov <mmu...@apache.org>:
>
> > Igniters,
> >
> >
> > I'd like to discuss with you some thoughts about getting colocated
> > data [1] from nodes via thin client (mostly the java thin client).
> >
> > - We do have partition awareness enabled for non-transactional data [2].
> > - We do have from now on partition awareness for caches with custom
> > affinity functions [3].
> > - We do NOT have an option to execute a transactional operation on
> > affinity node [4], however, I think it is possilbe to send a
> > transactional get request over the affinity channels instead of the
> > default one.
> >
> >
> > The process execution on the thin client side may looks like:
> >
> > open transaction (colocated get request) -> set the right client
> > context -> pick up the affinity node channel (instead of the default
> > one) -> send the request over this channel right to the destination
> > primaries.
> >
> > The interface improvement may looks like:
> >
> > IgniteClient {
> > public void withAffinityNode(String cacheName, Object affKey);
> > }
> >
> > IgniteClient affClient = Ignition.startClient(new ClientConfiguration()
> > .setAddresses("node1_address:10800", "node2_address:10800",
> > "node3_address:10800"))
> > .withAffinityNode("person", "affKey");
> >
> > try (ClientTransaction tx = affClient.transactions().txStart()
> > ) {
> > ClientCache<Integer, String> personCache = affClient.cache("person");
> > ClientCache<Integer, String> paymentsCache =
> > affClient.cache("payments");
> >
> > // personCache.get("affKey");
> > // paymentsCache.get(..);
> > }
> > catch (ClientException e) {
> > // Ignore.
> > }
> >
> >
> > Additional benefits:
> >
> > - ScanQuery, SqlQuery with #setLocal(true) flag right on the required
> > affinity channel;
> > - ClientCompute task right on the required affinity channel;
> >
> >
> > WDYT?
> >
> >
> > [1]
> >
> https://ignite.apache.org/docs/latest/data-modeling/affinity-collocation#affinity-colocation
> > [2]
> >
> https://ignite.apache.org/docs/latest/thin-clients/getting-started-with-thin-clients#partition-awareness
> > [3] https://issues.apache.org/jira/browse/IGNITE-17316
> > [4]
> >
> https://github.com/apache/ignite/blob/master/modules/core/src/main/java/org/apache/ignite/internal/client/thin/TcpClientCache.java#L994
> >
>
>
> --
>
> Best regards,
> Alexei Scherbakov
>
