Hi Mohammad, Queryable State works in some cases: https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/stream/state/queryable_state.html
As much as I know, this is the only way to access Flink's state from outside, until we have Savepoint API coming in 1.9. --- Oytun Tez *M O T A W O R D* The World's Fastest Human Translation Platform. oy...@motaword.com — www.motaword.com On Tue, Aug 6, 2019 at 9:52 AM Mohammad Hosseinian < mohammad.hossein...@id1.de> wrote: > Hi Alex, > > Thanks for your reply. The application is streaming. The issue with using > messaging channels for such kind of communication is the 'race condition'. > I mean, when you have parallel channels of communication (one for the main > flow of your streaming application and one for bringing 'stated/current' > objects to desired processing nodes), then the order of messages are not > preserved and it might lead to incorrect result of your application. That > was the reason why I was wondering if there is any 'synchronous' way of > accessing the Flink state. > > BR, Moe > > > On 06/08/2019 13:25, Протченко Алексей wrote: > > Hi Mohammad, > > which types of applications do you mean? Streaming or batch ones? In terms > of streaming ones queues like Kafka or RabbitMq between applications should > be the best way I think. > > Best regards, > Alex > > > Вторник, 6 августа 2019, 12:21 +02:00 от Mohammad Hosseinian > <mohammad.hossein...@id1.de> <mohammad.hossein...@id1.de>: > > Hi all, > > > We have a network of Flink applications. The whole cluster receives > 'state-update' messages from the outside, and there is one Flink > application in our cluster that 'merges' these updates and creates the > actual, most up-to-date, state of the 'data-objects' and passes it to the > next process. It does this, using a stateful stream processing with a > `KeyedProcessFunction` object. In our processing logic, there are nodes > that require to access the actual state of the objects when they receive > one or more 'object-id's from the previous Flink application. We do not > propagate the actual-state of the objects since, not all types of the > objects are relevant to all processes in the cluster, so we saved some > network/storage overhead there. > > The question is: for such scenario, what is the best way to expose the > Flink state to another Flink application? I am aware of 'Queryable states', > but I am not sure if this feature has been designed and is suitable for our > use-case or not? > > > Thank you very much in advance. > > > BR, Moe > -- > > *Mohammad Hosseinian* > Software Developer > Information Design One AG > > Phone +49-69-244502-0 > Fax +49-69-244502-10 > Web *www.id1.de <http://www.id1.de>* > > > Information Design One AG, Baseler Strasse 10, 60329 Frankfurt am Main, > Germany > Registration: Amtsgericht Frankfurt am Main, HRB 52596 > Executive Board: Robert Peters, Benjamin Walther, Supervisory Board: > Christian Hecht > > > > -- > Протченко Алексей > > -- > > *Mohammad Hosseinian* > Software Developer > Information Design One AG > > Phone +49-69-244502-0 > Fax +49-69-244502-10 > Web *www.id1.de <http://www.id1.de>* > > > Information Design One AG, Baseler Strasse 10, 60329 Frankfurt am Main, > Germany > Registration: Amtsgericht Frankfurt am Main, HRB 52596 > Executive Board: Robert Peters, Benjamin Walther, Supervisory Board: > Christian Hecht >
