Pavel, > OP_QUERY_CONTINUOUS_END_NOTIFICATION is another client -> server message I think you mean "server -> client" here.
But I still didn't get why do we need it. I've briefly looked to the POC implementation and, as far as I understand, OP_QUERY_CONTINUOUS_END_NOTIFICATION can be sent only when OP_RESOURCE_CLOSE is received by server (client closes the CQ explicitly). If client closes CQ it doesn't want to receive any new events. Why can't we just ignore events for this CQ after that moment? Also, in current implementation OP_QUERY_CONTINUOUS_END_NOTIFICATION is sent before OP_RESOURCE_CLOSE response, so OP_RESOURCE_CLOSE response can be used the same way as OP_QUERY_CONTINUOUS_END_NOTIFICATION. Such notification (or something more generalized like OP_RESOURCE_CLOSED) can be helpful if CQ is closed by someone else (for example if administrator call QueryMXBean.cancelContinuous), but AFAIK now we don't have callbacks for this action on user side. ср, 15 июл. 2020 г. в 01:26, Pavel Tupitsyn <ptupit...@apache.org>: > Igniters, > > I've made an important change to the IEP (and the POC): > OP_QUERY_CONTINUOUS_END_NOTIFICATION is another client -> server message > that notifies the client that the query has stopped and no more events > should be expected. > > This is important because client can't immediately stop listening > for OP_QUERY_CONTINUOUS_EVENT_NOTIFICATION > after sending OP_RESOURCE_CLOSE - some more events can be present in one of > the buffers/queues of the server and/or the OS. > > Let me know if this makes sense. > > On Tue, Jul 14, 2020 at 3:25 PM Pavel Tupitsyn <ptupit...@apache.org> > wrote: > > > I've removed Initial Query from the POC and IEP (left a note there about > > the decision). > > > > Since there are no other comments and concerns, I'll move on with the > > final implementation. > > > > On Fri, Jul 10, 2020 at 4:14 PM Pavel Tupitsyn <ptupit...@apache.org> > > wrote: > > > >> Igor, Alex, > >> > >> I was aware of the duplicates issue with the initial query, but I did > not > >> give it a second thought. > >> > >> Now I see that Vladimir was right - Initial query seems to be pointless, > >> since users can > >> achieve the same by simply invoking the regular query. > >> > >> I will remove Initial Query from the IEP and POC next week if there are > >> no objections by then. > >> > >> > >> On Fri, Jul 10, 2020 at 3:58 PM Alex Plehanov <plehanov.a...@gmail.com> > >> wrote: > >> > >>> Igor, Pavel, > >>> > >>> Here is discussion about removal: [1] > >>> > >>> [1] : > >>> > >>> > http://apache-ignite-developers.2346864.n4.nabble.com/ContinuousQueryWithTransformer-implementation-questions-2-td21418i20.html#a22041 > >>> > >>> пт, 10 июл. 2020 г. в 17:44, Igor Sapego <isap...@apache.org>: > >>> > >>> > Can not find proposal to remove them, so maybe it was not on devlist, > >>> > but here is discussion about the problem: [1] > >>> > > >>> > [1] - > >>> > > >>> > > >>> > http://apache-ignite-developers.2346864.n4.nabble.com/Continuous-queries-and-duplicates-td39444.html > >>> > > >>> > Best Regards, > >>> > Igor > >>> > > >>> > > >>> > On Fri, Jul 10, 2020 at 3:27 PM Pavel Tupitsyn <ptupit...@apache.org > > > >>> > wrote: > >>> > > >>> > > > What's about "stop" message? How can user unsubscribe from > >>> receiving > >>> > > notifications? > >>> > > OP_RESOURCE_CLOSE is used for that. I've updated the IEP in an > >>> attempt to > >>> > > make this cleaner. > >>> > > > >>> > > > I've seen discussions on removing initial query from continuous > >>> > queries > >>> > > Interesting, I'm not aware of this. Can you please link those > >>> > discussions? > >>> > > > >>> > > On Fri, Jul 10, 2020 at 2:04 PM Igor Sapego <isap...@apache.org> > >>> wrote: > >>> > > > >>> > > > Pavel, > >>> > > > > >>> > > > What's about "stop" message? How can user unsubscribe from > >>> receiving > >>> > > > notifications? > >>> > > > > >>> > > > Also, I believe I've seen discussions on removing initial query > >>> from > >>> > > > continuous queries, > >>> > > > as there are not any guarantees about getting consistent results > >>> with > >>> > > them. > >>> > > > Should > >>> > > > we avoid adding them in thin protocol maybe? It would also > simplify > >>> > > > protocol a lot. > >>> > > > > >>> > > > Best Regards, > >>> > > > Igor > >>> > > > > >>> > > > > >>> > > > On Tue, Jun 30, 2020 at 2:39 PM Pavel Tupitsyn < > >>> ptupit...@apache.org> > >>> > > > wrote: > >>> > > > > >>> > > > > Igniters, > >>> > > > > > >>> > > > > Let's discuss Thin Client Continuous Queries, > >>> > > > > I've prepared an IEP [1] and a PoC [2]. > >>> > > > > > >>> > > > > [1] > >>> > > > > > >>> > > > > > >>> > > > > >>> > > > >>> > > >>> > https://cwiki.apache.org/confluence/display/IGNITE/IEP-50%3A+Thin+Client+Continuous+Queries > >>> > > > > > >>> > > > > [2] https://github.com/apache/ignite/pull/7966 > >>> > > > > > >>> > > > > >>> > > > >>> > > >>> > >> >
