The Flink SQL Cookbook by Ververica is a hands-on, example-rich guide to mastering Apache Flink SQL for real-time stream processing. It offers a wide range of self-contained recipes, from basic queries and table operations to more advanced use cases like windowed aggregations, complex joins, user-defined functions (UDFs), and pattern detection. These examples are designed to be run on the Ververica Platform, and as such, the cookbook doesn’t include instructions for setting up a Flink cluster.

To help you run these recipes locally and explore Flink SQL without external dependencies, this post walks through setting up a fully functional local Flink cluster using Docker Compose. With this setup, you can experiment with the cookbook examples right on your machine.

Change data capture (CDC) is a data integration pattern to track changes in a database so that actions can be taken using the changed data. Debezium is probably the most popular open source platform for CDC. Originally providing Kafka source connectors, it also supports a ready-to-use application called Debezium server. The standalone application can be used to stream change events to other messaging infrastructure such as Google Cloud Pub/Sub, Amazon Kinesis and Apache Pulsar. In this post, we develop a CDC solution locally using Docker. The source of the theLook eCommerce is modified to generate data continuously, and the data is inserted into multiple tables of a PostgreSQL database. Among those tables, two of them are tracked by the Debezium server, and it pushes row-level changes of those tables into Pub/Sub topics on the Pub/Sub emulator. Finally, messages of the topics are read by a Python application.

In this post, we develop an Apache Beam pipeline using the Python SDK and deploy it on an Apache Flink cluster via the Apache Flink Runner. Same as Part I, we deploy a Kafka cluster using the Strimzi Operator on a minikube cluster as the pipeline uses Apache Kafka topics for its data source and sink. Then, we develop the pipeline as a Python package and add the package to a custom Docker image so that Python user code can be executed externally. For deployment, we create a Flink session cluster via the Flink Kubernetes Operator, and deploy the pipeline using a Kubernetes job. Finally, we check the output of the application by sending messages to the input Kafka topic using a Python producer application.

Flink Kubernetes Operator acts as a control plane to manage the complete deployment lifecycle of Apache Flink applications. With the operator, we can simplify deployment and management of Python stream processing applications. In this series, we discuss how to deploy a PyFlink application and Python Apache Beam pipeline on the Flink Runner on Kubernetes. In Part 1, we first deploy a Kafka cluster on a minikube cluster as the source and sink of the PyFlink application are Kafka topics. Then, the application source is packaged in a custom Docker image and deployed on the minikube cluster using the Flink Kubernetes Operator. Finally, the output of the application is checked by sending messages to the input Kafka topic using a Python producer application.

Amazon MSK can be configured as an event source of a Lambda function. Lambda internally polls for new messages from the event source and then synchronously invokes the target Lambda function. With this feature, we can develop a Kafka consumer application in serverless environment where developers can focus on application logic. In this lab, we will discuss how to create a Kafka consumer using a Lambda function.

Kafka Connect is a tool for scalably and reliably streaming data between Apache Kafka and other systems. It makes it simple to quickly define connectors that move large collections of data into and out of Kafka. In this lab, we will discuss how to create a data pipeline that ingests data from a Kafka topic into a DynamoDB table using the Camel DynamoDB sink connector.

The value of data can be maximised when it is used without delay. With Apache Flink, we can build streaming analytics applications that incorporate the latest events with low latency. In this lab, we will create a Pyflink application that writes accumulated taxi rides data into an OpenSearch cluster. It aggregates the number of trips/passengers and trip durations by vendor ID for a window of 5 seconds. The data is then used to create a chart that monitors the status of taxi rides in the OpenSearch Dashboard.

In this lab, we will create a Pyflink application that exports Kafka topic messages into a S3 bucket. The app enriches the records by adding a new column using a user defined function and writes them via the FileSystem SQL connector. This allows us to achieve a simpler architecture compared to the original lab where the records are sent into Amazon Kinesis Data Firehose, enriched by a separate Lambda function and written to a S3 bucket afterwards. While the records are being written to the S3 bucket, a Glue table will be created to query them on Amazon Athena.

In this lab, we will create a Pyflink application that reads records from S3 and sends them into a Kafka topic. A custom pipeline Jar file will be created as the Kafka cluster is authenticated by IAM, and it will be demonstrated how to execute the app in a Flink cluster deployed on Docker as well as locally as a typical Python app. We can assume the S3 data is static metadata that needs to be joined into another stream, and this exercise can be useful for data enrichment.

Stream processing technology is becoming more and more popular with companies big and small because it provides superior solutions for many established use cases such as data analytics, ETL, and transactional applications, but also facilitates novel applications, software architectures, and business opportunities. Beginning with traditional data infrastructures and application/data development patterns, this post introduces stateful stream processing and demonstrates to what extent it can improve the traditional development patterns. A consulting company can partner with her clients on their journeys of adopting stateful stream processing, and it can bring huge opportunities. Those opportunities are summarised at the end.