The basics and complications of gRPC

Arrow Flight is built on two things:

• The Arrow IPC format (which we covered in Chapter 3, Format and Memory Handling)
• gRPC (https://grpc.io), an open source RPC framework built on top of Protocol Buffers (Protobuf) for high-performance services

Since we’ve already covered the Arrow IPC format, let’s first quickly look at what gRPC is and how to use it. To do that, we need to talk about application programming interfaces (APIs).

Building modern APIs for data

We’ve used the word “API” a lot already in this book, and most of you are likely at least already conceptually familiar with the idea of an API, but let’s quickly define what we’re talking about.

While the term API has been around since at least the 1960s, the scope of what it refers to has broadened considerably. Initially, it was used solely to describe an end user-facing interface, at the time just called application...