Unlimited Infrastructure Monitoring for Free Enabled by Apache Pulsar

The Netdata Agent is free, open source single-node monitoring software. Netdata Cloud is a free, closed source, software-as-a-service that brings together metadata from endpoints running the Netdata Agent, giving a complete view of the health and performance of an infrastructure. All the metrics remain on the Netdata Agent, making Netdata Cloud the focal point of a distributed, infinitely scalable, low cost solution.

The heart of Netdata Cloud is Pulsar. Almost every message coming from and going to the open source agents passes through Pulsar. Pulsar's infinite number of topics has given us the flexibility we needed and in some cases, every single Netdata Agent has its own unique Pulsar topic.A single message from an agent or from a service that processes a front end request can trigger several other Pulsar messages, as we also use Pulsar for communication between microservices (using a CQRS pattern with shared subscriptions for scalability).

The reliable persistence of messages has allowed us to replay old events to rebuild old and build new materialized views and debug specific production issues. It's also what will enable us to implement an event sourcing pattern, for a new set of features we want to introduce shortly.We have had a few issues with a specific client and our shared subscriptions that we're working on resolving, but overall Pulsar has proven to be one of the most reliable parts of our infrastructure and we decided to proceed with a managed services agreement.