1# Azure Service Bus
2 
3Enterprise messaging with queues and pub/sub topics.
4 
5## When to Use
6 
7- Reliable message delivery
8- Pub/sub messaging patterns
9- Message ordering requirements
10- Dead-letter handling
11- Transaction support
12- Enterprise integration
13 
14## Required Supporting Resources
15 
16| Resource | Purpose |
17|----------|---------|
18| None required | Service Bus is self-contained |
19| Key Vault | Store connection strings (legacy) |
20 
21## SKU Selection
22 
23| SKU | Features | Use Case |
24|-----|----------|----------|
25| Basic | Queues only, 256KB messages | Simple messaging |
26| Standard | Topics, 256KB messages | Pub/sub patterns |
27| Premium | 100MB messages, VNET, zones | Enterprise, high throughput |
28 
29## Environment Variables
30 
31### Managed Identity (Recommended)
32 
33| Variable | Value |
34|----------|-------|
35| `SERVICEBUS__fullyQualifiedNamespace` | `<namespace>.servicebus.windows.net` |
36| `SERVICEBUS_NAMESPACE` | Namespace name (for SDK) |
37| `SERVICEBUS_QUEUE` | Queue name |
38 
39**Required RBAC roles:**
40- `Azure Service Bus Data Sender` (69a216fc-b8fb-44d8-bc22-1f3c2cd27a39) - for sending
41- `Azure Service Bus Data Receiver` (4f6d3b9b-027b-4f4c-9142-0e5a2a2247e0) - for receiving
42 
43### Connection String (Legacy)
44 
45| Variable | Value |
46|----------|-------|
47| `SERVICEBUS_CONNECTION_STRING` | Connection string (Key Vault) |
48| `SERVICEBUS_NAMESPACE` | Namespace name |
49| `SERVICEBUS_QUEUE` | Queue name |
50 
51## References
52 
53- [Bicep Patterns](bicep.md)
54- [Messaging Patterns](patterns.md)
55