Azure Traffic Manager
What it is
Azure Traffic Manager is a DNS-based global traffic load balancer for public-facing applications. It chooses a healthy endpoint—an Azure or external internet-facing service—when a client looks up the Traffic Manager name. It is not an inline proxy between the user and the application.
Why it exists
For global availability, latency, or planned maintenance, a team may need to direct new clients to different regional endpoints. Because Traffic Manager makes a DNS decision rather than proxying each request, it can point clients to Azure, on-premises, or other public endpoints.
Key ideas
- Priority: primary/backup failover. Weighted: divide traffic by proportion. Performance: directs a client to the endpoint with lowest latency. Geographic: directs by the client’s geographic region. Other methods include multi-value and subnet routing.
- Health monitoring: Traffic Manager checks endpoints and can stop returning an unhealthy endpoint for new DNS responses.
- DNS caching matters: a client or recursive resolver can retain a prior answer for its DNS time-to-live (TTL). Failover changes new DNS responses; it does not move an already-open connection.
- It does not provide HTTP routing, TLS termination, or a web-application firewall. Those are reasons to consider Front Door or Application Gateway.
Northwind example
Northwind runs the ordering site in two regions. Its Traffic Manager profile uses priority routing: the primary regional endpoint is returned while healthy, and the standby is returned when the primary is unhealthy. A customer who has already resolved the old endpoint—or has an active connection—may not switch immediately, so the application and its data design still need their own resilience plan.
How it fits
[users worldwide]
│ DNS query → returns best endpoint IP
▼
[Traffic Manager profile (DNS)]
│ Performance routing
├──→ [region 1 LB] [region 2 LB] [region 3 LB]
(endpoints monitored for health)Exam notes
- Traffic Manager = DNS-level, global routing; no inline proxy, TLS termination, or Layer 4/7 forwarding.
- Compare with Front Door (L7/global proxy + WAF) and Load Balancer (L4, regional).
- Priority/Weighted/Performance/Geographic methods are exam staples.
Related
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