Kafka Tools – kafka-delete-records While working with kafka we, sometimes, need to purge records from a topic. This is specially needed in a development environment where we just want to get rid of some records and want to keep the other ones. Previously we have discussed how we can purge all records from a topic… Continue reading »
com.esotericsoftware.kryo.KryoException: Unusual solution upgrading Flink While upgrading from Flink from 1.4 to a newer version 1.6.1, there are a few build issues. After we fix the issues, suddenly we started getting KryoException. Why are we getting this and how it this related to the upgrade? Let’s start with the exception message. If you try to… Continue reading »
Apache Flink – mapWithState on KeyedStream mapWithState operator provides a syntactic ease for keeping ValueState for map operations on KeyedStreams in Apache Flink. It is specially useful for doing a running count on the data. That is exactly what we are going to try in this post. Just remember that you don’t have to return… Continue reading »
Kafka Connect – Single Message Transforms (SMTs) Single Message Transforms were released with 0.10.2 release [ Release notes ]. It provides us the ability to transform a message before they get in or out of a connector using Kafka Connect. Source Transforms Source connector can be configured with a list of transforms. These transforms are… Continue reading »
Downloading Flink You can download flink from it’s Apache’s site. We are downloading Flink 1.6, which is the latest version available. https://flink.apache.org/downloads.html It requires Java version 8. Running Flink Cluster Let’s start the cluster. We can just run it directly from bin folder using start-cluster.sh utility available with the download. Alternatively we can run it… Continue reading »