From 66846f47584a17c42fe80995d26bc26fbea41095 Mon Sep 17 00:00:00 2001 From: Maria Grimaldi Date: Wed, 18 Dec 2024 00:21:03 +0100 Subject: [PATCH] docs: drop references to event carried state transfer pattern --- docs/decisions/0016-event-design-practices.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/decisions/0016-event-design-practices.rst b/docs/decisions/0016-event-design-practices.rst index 11ec02fc..b72f9bbf 100644 --- a/docs/decisions/0016-event-design-practices.rst +++ b/docs/decisions/0016-event-design-practices.rst @@ -17,12 +17,12 @@ Decision We have compiled a list of suggested practices taken from `Event-Driven Microservices`_ and the `Event-Driven article`_ that we recommend reviewing and following when designing an Open edX Event and contributing to the library. The goal is to implement events that are consistent with the architecture, reusable, and maintainable over time. #. An event should describe as accurately as possible what happened (what) and why it happened (why). It must contain enough information for consumers to understand the message. For instance, if an event is about a user enrollment, it should contain the user's data, the course data, and the enrollment status and the event should be named accordingly. -#. Design events to be self-descriptive and self-contained. The event should contain all the information necessary about what took place for consumers to react to the event without consulting other data sources. This is known as the `Event-Carried State Transfer pattern`_. +#. Design events to be self-descriptive and self-contained. The event should contain all the information necessary about what took place for consumers to react to the event without consulting other data sources. #. Avoid ambiguous data fields or fields with multiple meaning. For instance, if an event contains a field called ``status`` it should be clear what the status represents. If the status can have multiple meanings, consider splitting the event into multiple events or adding a new field to clarify the status. #. Design events with a single responsibility in mind. Each event should represent a single action or fact that happened in the system. If an event contains multiple actions, consider splitting it into multiple events. For instance, if the course grade is updated to pass or fail, there should be two events: one for the pass action and another for the fail action. #. Avoid adding flow-control information or business logic to events. Events should be solely a representation of what took place. If a field is necessary to control the behavior of the consumer, consider moving it to the consumer side. So, design the event so it is small, well-defined and only contain relevant information. #. Use appropriate data types and formats for the event fields. Don't use generic data types like strings for all fields. Use specific data types like integers, floats, dates, or custom types when necessary. -#. Ensure the event carries all necessary data to prevent runtime dependencies with other services. An event doesn't need to contain all the data of the entities involved, but it should contain enough information for consumers to not immediately need to query other services to process the event. This might be not always possible, but it is good to keep in mind. +#. Ensure the event carries all necessary data to prevent runtime dependencies with other services. An event doesn't need to contain all the data of the entities involved, but it should contain enough information for consumers to not immediately need to query other services to understand what took place. This might be not always possible, but it is good to keep in mind. #. Manage the granularity of the event so it is not too coarse (generic name with too much information) or too fine-grained (specific name with too little information). It should be expressive enough to be useful. #. When designing an event, consider the consumers that will be using it. What information do they need to react to the event? What data is necessary for them to process the event?