Kafka Streams – Resetting Application State I the previous post, we discussed that we might need to reprocess data during development during application development. Since Kafka Streams ensures the application state, it doesn’t pull and reprocess data. In this case, you might find yourself keep waiting for the join operations to get triggered, but to… Continue reading »
Building Serde for Kafka Streams Application While developing Kafka Streams applications, I found myself requiring some utility code over and over. One such code is to build Serde for custom types. It is better if it is refactored into separate types and used when needed. It has two methods specificAvroSerde and genericAvroSerde. It must be… Continue reading »
Kafka Tools – Mirror Maker MirrorMaker is a Kafka tools for copying data from one cluster to the other. In this post we are going to see how we can run Mirror Maker to copy data from one cluster to the other. This can be specially useful when we want to copy data between two… Continue reading »
Serde and Kafka Streams In order to push / pull messages from Kafka we need to use Serde. I have found that if you create a Serializer / Deserialzer like following then it becomes really useful to create the Serde for your types. You can also use the method to create a GenericSerde to serialize… Continue reading »
Kafka Streams Config’s General Properties In this post, I just need to add Kafka Stream configuration which I have to use over and over again for a Kafka streams application. This can be used when developing a new Kafka Streams application. First we need to introduce configurations for Stream. They include details of broker and… Continue reading »
Kafka Streams – Interactive Queries (Intra Application Instance) Kafka Streams application need to maintain KTables in an internal application store. It maintains the store using RocksDB. It even allows to query this store during application lifecycle anywhere from the application parts. Let’s first create a simple application KafkaStreamsInteractiveQueriesApp. It is a simple Scala Application. In… Continue reading »
Kafka Streams: Converting KStream to KTable There are no methods in KStream to convert into a KTable. But there are workarounds to do that. They are as follows: Write on a Kafka Topic and read back as Kable We can also write to an intermediate Kafka Topic and read it back using StreamBuilder. Here is… Continue reading »
Kafka Streams – Merging multiple KStream (s) In this post we are going to see how we can merge messages from multiple topics into a single topic in using Kafka Streams. In the example scenario, we will be using heart beat data for four sensors and merge into a single topic as follows: Here we… Continue reading »