Canary Deployment Strategy.md

title	notetype	date
Canary Deployment Strategy	feed	16-08-2022

Canary is a [[Deployment Strategy]] where we gradually shift traffic from version A to version B. This is usually done via weighted load balancing (e.g., 90% traffic to A, 10% traffic to B).

How it works

• before we start, we have 2 instances of A running and serving traffic
• we deploy 2 instances of B alongside them, and send 10% of traffic to them
• we confirm that version B acts as expected while handilng 10% traffic
• we switch all traffic from version A to version B

Tradeoffs

Pros:

• zero downtime
• testing new version on real traffic with a subset of random users, which allows us to monitor how new version behaves
• fast rollback

Cons:

• rollout speed is sacrificed for safety

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Status: #💡

References:

• Six Strategies for Application Deployment