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
