Cassandra is a column family database that uses the primary key to decide where to store data. Hence the primary key plays an important role. The key can be simple based on a single column or composite based on multiple columns. Spring Data has a great way to handle complex composite keys. — Data structure As an example, we will work with a database that stores IOT sensor events. The database has a keyspace called IOT and a column family called sensor events. For simplicity, the database cluster has only one node. …

Cassandra is a distributed database. It consists of multiple nodes forming a cluster. Spring Boot is a popular framework and has great integration with distributed databases including Cassandra. — Database cluster Let's create a database cluster locally using Docker and Docker Compose. The cluster will contain 3 nodes. A detailed explanation of the Cassandra local setup I described in the tutorial below:

Cassandra is a popular distributed NoSQL database. It is a highly available system with no single point of failure due to its clever architecture that allows persisting large amounts of data across multiple servers. — In this tutorial, I will show you how to create a Cassandra cluster with 3 nodes locally. The easiest way to create a cluster is with the help of Docker and Docker Compose. …

Postgres is a very popular SQL database. JSON is the most used format in programming. And Docker is a standard for microservices architecture. In this tutorial, I will show you how to insert data in JSON format into a database running on a Docker container. — Let's imagine that we have a table in a database used to persist information about customers such as id, full name, phone number, address, payment types, information if the customer is active or not, and the creation date. It is worth mentioning that address will be saved in a JSON…

Logs provide valuable information about the functioning of applications. Knowing how to analyze logs and extract required information fast and efficiently enables us to solve or even prevent some problems in production. AWS is the most used cloud provider and it has a cool tool for working with logs. This tutorial is about how to construct a query that will fetch the necessary information. — Set-Up

Grafana is a tool for visualizing logs and all sorts of metrics. It allows the creation of a wide variety of graphics. This tutorial is about how to run Grafana on a Docker container with previously created graphics. — The challenge Using a Docker container to run Grafana is very convenient because it allows us to skip installing process and create an instance with only one command. Another advantage of using Docker is that we can configure Grafana once and then reuse those configurations and share them with others if required…

When the application is in production, we must ensure it runs without problems. Good that we have useful tools: Prometheus and Grafana that are out there to help us catch production issues early and avoid disasters. This tutorial will show how to enable metrics in the Spring Boot application so they can be gathered by Prometheus and represented in Grafana. The setup is local using Docker and Docker Compose, so one can easily create it with only one command.

Prometheus is a powerful tool used for collecting metrics from a variety of devices. PromQL is a query language used to fetch necessary data used to analyze and for a graphical representation using tools such as Grafana. — Data Prometheus stores data as a time series. Each entry in Prometheus consists of a metric name, a set of labels, a UNIX timestamp, and a sample collected at that timestamp.

We are in the era of microservices. One of the advantages of microservices architecture is faster time to market. Development can be split into smaller parts, hence can be developed in parallel. Most of the time microservices communication is done by REST API. With that being said, a question arises…