Thanks Jan, super helpful! To summarize (I hope I've got it right), there are only two ways for external applications to access data derived from a KTable:
1. Inside the streams application that builds the KTable, create a KafkaStreams.store and expose to the outside via a service. 2. Convert the KTable to a stream and write to a new Kafka topic. Then external apps can just consume this feed. If we only care about the latest updates, make the topic log-compacted. Thanks, Pete On Thu, Dec 7, 2017 at 1:42 AM, Jan Filipiak <jan.filip...@trivago.com> wrote: > Hi, > > you should be able to retrieve your store with > > https://github.com/apache/kafka/blob/trunk/streams/src/main/ > java/org/apache/kafka/streams/KafkaStreams.java#L1021 > > This would give you access to the store from inside your current > application. In your Streams application your could then > expose this Store with a say REST or any other RPC interface, to let > applications from outside your JVM query it. > > So i would say the blogpost still applies quite well. > > Hope this helps > > Best Jan > > > On 07.12.2017 04:59, Peter Figliozzi wrote: > >> I've written a Streams application which creates a KTable like this: >> >> val myTable: KTable[String, GenericRecord] = myStream >> .groupByKey() >> .aggregate(myInitializer, myAdder, myStore) >> >> where myStore was configured like this: >> >> val myStore >> : Materialized[String, GenericRecord, KeyValueStore[Bytes, >> Array[Byte]]] = >> Materialized >> .as("my-store") >> .withKeySerde(Serdes.String()) >> .withValueSerde(genericValueSerde) >> >> What I'd like to do now is query (read) this store from a separate >> application. How do I query it in 1.0.0? With a KTable constructor, >> using >> the store string as the topic, i.e.: >> >> public <K,V> KTable<K,V> table( >> java.lang.String topic, >> Materialized<K,V,KeyValueStore<org.apache.kafka.common. >> utils.Bytes,byte[]>> >> materialized) >> >> Or some other way? >> >> I saw this blog post >> <https://blog.codecentric.de/en/2017/03/interactive-queries- >> in-apache-kafka-streams/> >> but it appears to be only applicable to the older version of Kafka (please >> correct me if I'm wrong). >> >> Thanks, >> >> Pete >> >> >
