Gateway-First Deploy and Rollback Order¶
Specification¶
The full specification below is extracted from Chapter 18: Configuration, Migration, Backup, and Rollout.
Type: workflow
**sim-id:** gateway-first-deploy-rollback<br/>
**Library:** Mermaid<br/>
**Status:** Specified
Bloom Taxonomy: Analyze (L4)
Bloom Taxonomy Verb: trace, differentiate
Learning objective: Trace the deploy order and the reverse rollback order across the gateway, processors, and stateless roles, and explain why the gateway sits at both ends of the sequence.
Purpose: A Mermaid flowchart with two tracks sharing the same role nodes — "Deploy order" and "Rollback order" — visiting roles in opposite sequence, to make the asymmetry visually obvious.
Deploy order track: "Gateway (first)" -> "Processors (Termination Grace Period 60s)" -> "Summarizer" -> "Stateless APIs & Dashboards (last)".
Rollback order track: "Stateless APIs & Dashboards (first)" -> "Summarizer" -> "Processors" -> "Gateway (last)".
A shared side note connects both tracks: "Expand-Contract Rollback: schema never mutated out from under a version, so adjacent versions can run against it at once."
Interactive features: Every node has a Mermaid click directive opening an infobox on that role's rollout behavior (clicking "Processors" explains the Termination Grace Period; clicking "Gateway" explains why it is the only role whose downtime loses data). Clicking the side note explains Expand-Contract Rollback. A toggle highlights one track and dims the other.
Color coding: Deploy track teal, rollback track amber with reversed arrows, both gateway nodes outlined to draw the eye to the asymmetry.
Responsive design: Tracks stack vertically on narrow viewports, preserving reading order and all click handlers.