Apache Pulsar in Action

2 Pulsar concepts and architecture

This chapter covers

• Pulsar’s physical architecture

• Pulsar’s logical architecture

• Message consumption and the subscription types provided by Pulsar

• Pulsar’s message retention, expiration, and backlog policies

Now that you have been introduced to the Pulsar messaging platform and how it compares to other messaging systems, we will drill down into the low-level architectural details and cover some of the unique terminology used by the platform. If you are unfamiliar with messaging systems and distributed systems, then it might be difficult to wrap your head around some of Pulsar’s concepts and terminology. I will start with an overview of Pulsar’s physical architecture before diving into how Pulsar logically ...