Apache Flink – Change Port for web front end Apache Flink runs the dashboard on port 8081. Since this is a common port there might be conflict with some other services running on the same machines. You might encounter this scenario especially during development when many services are running on the your development machine. But… Continue reading »
IntelliJ & Scala – Could not load main class This is one of the most common error we see when we get new code from a source repository. We might also see it when we create a new Scala project. As we run the application, the console shows could not load main class The solution… Continue reading »
IntelliJ – Add New Scala Class Option – Not Available You might get into this problem every time a new Scala project is created. By default, the support of Scala is not available. So when you right click your src folder to add Scala Class, you might be disappointed to see no option for adding… Continue reading »
Angular Material Toggle Buttons Group with Binding In this post we are going to create an Angular App to use Button toggle groups from Angular material. We are going to do data binding of these buttons and generate the buttons using a list in the code behind in the component class. Let’s first create a… Continue reading »
Kafka-Consumer-Groups – Kafka CLI Tools Kafka-Consumer-Groups is a CLI tool which can be used to get the message consumption from Kafka. The tool can be used to get the list of topics and partitions consumed by a consumer group. It also details if a consumer is lagging in consumption of the messages. First we need… Continue reading »
Deleting Connectors from Kafka Connect A connector can be deleting using Kafka Connect’s REST API. Here is the curl command:
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 »
Kafka Connect Issues: Found null value for non-optional schema In a custom connector, you might encounter the following issue: Here we have a schema defined for one of our custom connector: Now you would see the error when you create a SourceRecord with a value missing the non-optional fields.
Viewing systemctl logs for RHEL7 using journalctl The logs for systemctl service can be viewed using journalctl. Here we are viewing the logs for a process with PID 87920.
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 »