Welcome to the Cadence Community Spotlight update!

This is the second in our series of monthly updates focused on the Cadence community and news about what you have been doing with Cadence. We hope that you enjoyed last month's update and are keen to find out what has been happening.

Please see below for a short activity roundup of what has happened recently in the community.

Announcements​

Just in case you missed it the alpha version of the Cadence notification service has been released. Details can be found at the following link: Cadence Notification Service

Thanks very much to everyone that worked on this!

Welcome to our very first Cadence Community Spotlight update!

This monthly update focuses on news from the wider Cadence community and is all about what you have been doing with Cadence. Do you have an interesting project that uses Cadence? If so then we want to hear from you. Also if you have any news items, blogs, articles, videos or events where Cadence has been mentioned then that is good too. We want to showcase that our community is active and is doing exciting and interesting things.

Please see below for a short round up of things that have happened recently in the community.

Background​

Cadence historically has been using TChannel transport with Thrift encoding for both internal RPC calls and communication with client SDKs. gRPC is becoming a de-facto industry standard with much better adoption and community support. It offers features such as authentication and streaming that are very relevant for Cadence. Moreover, TChannel is being deprecated within Uber itself, pushing an effort for this migration. During the last year we’ve implemented multiple changes in server and SDK that allows users to use gRPC in Cadence, as well as to upgrade their existing Cadence cluster in a backward compatible way. This post tracks the completed work items and our future plans.

Our Approach​

With ~500 services using Cadence at Uber and many more open source customers around the world, we had to think about the gRPC transition in a backwards compatible way. We couldn’t simply flip transport and encoding everywhere. Instead we needed to support both protocols as an intermediate step to ensure a smooth transition for our users.

Cadence was using Thrift/TChannel not just for the API with client SDKs. They were also used for RPC calls between internal Cadence server components and also between different data centers. When starting this migration we had a choice of either starting with public APIs first or all the internal things within the server. We chose the latter one, so that we could gain experience and iterate faster within the server without disruption to the clients. With server side done and listening for both protocols, dynamic config flag was exposed to switch traffic internally. It allowed gradual deployment and provided an option to rollback if needed.

Are you a current Cadence user, do you operate Cadence services, or are you interested in learning about workflow technologies and wonder what problems Cadence could solve for you? We would like to talk to you!

Our team has spent a significant amount of time working with users and partner teams at Uber to design, scale and operate their workflows. This helps our users understand the technology better, smooth their learning curve and ramp up experience, and at the same time allows us to get fast and direct feedback so we can improve the developer experience and close feature gaps. As our product and community grows, we would like to expand this practice to our users in the OSS community. For the first time ever, members of the Cadence team along with core contributors from the community will host bi-weekly office hours to answer any questions you have about Cadence, or workflow technology in general. We can also dedicate future sessions to specific topics that have a common interest. Please don’t hesitate to let us know your thoughts.

Please join a session if you would like to talk about any of the following topics:

1. Understand what Cadence is and why it might be useful for you and your company
2. Guidance about running Cadence services and workers in production
3. Workflow design and operation consultation
4. Product update, future roadmaps as well as collaboration opportunities

Building and maintaining a healthy and growing community is the key to the success of Cadence, and one of the top priorities for our team. We would like to use the office hours as an opportunity to understand and help our customers, seek feedback, and forge partnerships. We look forward to seeing you in one of the meetings.

Upcoming Office Hours

As we have a geo-distributed userbase, we are still trying to figure out a time that works for most of the people. In the meanwhile, we will manually schedule the first few instances of the meeting until we settle on a fixed schedule. Our next office hours will take place on Thursday, October 21 2pm-3pm PT/5pm-6pm EST/9pm-10pm GMT. Please join via this zoom link.

Dear valued Cadence users and developers,

Some of you might have read Temporal’s recent announcement about their decision to drop the support for the Cadence project. This message caused some confusion in the community, so we would like to take this opportunity to clear things out.

First of all, Uber is committed to the long-term success of the Cadence project. Since its inception 5 years ago, use cases built on Cadence and their scale have grown significantly at Uber. Today, Cadence powers a variety of our most business-critical use cases (some public stories are available here and here). At the same time, the Cadence development team at Uber has enjoyed rapid growth with the product and has been driving innovations of workflow technology across the board, from new features (e.g. graceful failover, workflow shadowing, UI improvements) to better engineering foundations (e.g. gRPC support, multi-tenancy support), all in a backwards compatible manner. Neither Uber’s use nor support of Cadence is going to change with Temporal’s announcement. We have a long list of features and exciting roadmaps ahead of us, and we will share more details in our next meetup in November ‘21. As always we will continue to push the boundaries of scale and reliability as our usage within Uber grows.