Topology¶

Topology is a logical representation of a ProcessorTopology.

Topology is a facade to InternalTopologyBuilder (with all methods delegating to it).

Creating Instance¶

Topology takes no arguments to be created.

Topology is a part of the public API of Kafka Streams and can be created directly or indirectly for StreamsBuilder.

InternalTopologyBuilder¶

Topology creates an InternalTopologyBuilder when created.

addGlobalStore¶

<KIn, VIn> Topology addGlobalStore(
  StoreBuilder<?> storeBuilder,
  String sourceName,
  TimestampExtractor timestampExtractor,
  Deserializer<KIn> keyDeserializer,
  Deserializer<VIn> valueDeserializer,
  String topic,
  String processorName,
  ProcessorSupplier<KIn, VIn, Void, Void> stateUpdateSupplier)

addGlobalStore requests the InternalTopologyBuilder to add a global store.

addProcessor¶

Topology addProcessor(
  String name,
  ProcessorSupplier<KIn, VIn, KOut, VOut> supplier,
  String... parentNames)

addProcessor requests the InternalTopologyBuilder to add a processor.

If there are any state stores associated with the processor, addProcessor requests the InternalTopologyBuilder to add them.

addSource¶

Topology addSource(...) // (1)

1. There are over 10 different addSources

addSource requests the InternalTopologyBuilder to add a new source (node) (with the given arguments).

Demo¶

import org.apache.kafka.streams.Topology
val topology = new Topology