知鸦日报2024-02-11

We’ve previously spoken in great detail about how Precision Time Protocol is being deployed at Meta, including the protocol itself and Meta’s precision time architecture.

As we deployed PTP into one of our data centers, we were also evaluating and testing alternative PTP clients. In doing so, we soon realized that we could eliminate a lot of complexity in the PTP protocol itself that we experienced during data center deployments while still maintaining complete hardware compatibility with our existing equipment.

This is how the idea of Simple Precision Time Protocol (SPTP) was born.

But before we dive under the hood of SPTP we should explore why the IEEE 1588 G8265.1 and G8275.2 unicast profiles (here, we just call them PTP) weren’t a perfect fit for our data center deployment.

In September, 2020, our team at Shopify released a Ruby gem named Packwerk, a tool to enforce boundaries and modularize Rails applications. Since its release, Packwerk has taken on a life of its own, inspiring blog posts, conference talks, and even an entire gem ecosystem. Its popularity is an indication that Packwerk clearly filled a void in the Rails community.

Packwerk is a static analysis tool, similar to tools like Rubocop and Sorbet. Applied to a codebase, it analyzes constant references to help decouple code and organize it into well-defined packages.

But Packwerk is more than just a tool. Over the years, Packwerk’s approach to modularity has come to embody distinct and sometimes conflicting perspectives on code organization and its evolution. Packwerk’s feedback can change the entire trajectory of a codebase to a degree that distinguishes it from other tools of its kind.

This retrospective is our effort, as the team that developed Packwerk at Shopify, to shine a light on our learnings working with the tool, concerns about its use, and hopes for its future.

The world of Big Data is generally characterized by the big 3V’s - Volume, Velocity, and Variety. But here is one more V which is getting increasingly spotlighted in the world of big data which is Veracity.