Canary Releases: Progressive Delivery Strategies

Canary releases gradually roll out changes to a subset of users before full deployment.

Canary vs Blue-Green#

Blue-Green: 100% traffic switch
┌──────────┐     ┌──────────┐
│  v1.0.0  │ ──▶ │  v2.0.0  │
│   100%   │     │   100%   │
└──────────┘     └──────────┘

Canary: Gradual traffic shift
┌──────────┬──────────┐
│  v1.0.0  │  v2.0.0  │
│   95%    │    5%    │  ← Start
└──────────┴──────────┘
       ↓
┌──────────┬──────────┐
│  v1.0.0  │  v2.0.0  │
│   50%    │   50%    │  ← Progress
└──────────┴──────────┘
       ↓
┌──────────┬──────────┐
│  v1.0.0  │  v2.0.0  │
│    0%    │   100%   │  ← Complete
└──────────┴──────────┘