Azure Cosmos DB
Globally distributed, multi-model database for low-latency data at scale.
When to Use
- Global distribution requirements
- Multi-model data (document, graph, key-value)
- Variable and unpredictable throughput
- Low-latency reads/writes at scale
- Flexible schema requirements
Required Supporting Resources
| Resource | Purpose |
|---|---|
| None required | Cosmos DB is fully managed |
| Key Vault | Store connection strings (recommended) |
Capacity Modes
| Mode | Use Case | Billing |
|---|---|---|
| Serverless | Variable/low traffic, dev/test | Per request |
| Provisioned | Predictable workloads | Per RU/s |
| Autoscale | Variable but predictable peaks | Per max RU/s |
Consistency Levels
| Level | Latency | Consistency |
|---|---|---|
| Strong | Highest | Linearizable |
| Bounded Staleness | High | Bounded |
| Session | Medium | Session-scoped |
| Consistent Prefix | Low | Prefix ordering |
| Eventual | Lowest | Eventually consistent |
Recommendation: Use Session for most applications.
Environment Variables
| Variable | Value |
|---|---|
COSMOS_CONNECTION_STRING |
Primary connection string (Key Vault reference) |
COSMOS_ENDPOINT |
Account endpoint URL |
COSMOS_DATABASE |
Database name |