- What are Traffic Manager "DNS Queries"?
Whenever a user accesses your application, a DNS query is used to map the name of your service to its IP address. By providing different responses to different DNS queries, Traffic Manager allows you to load balance incoming traffic across multiple hosted Windows Azure services whether they're running in the same datacenter or across different datacenters around the world.
Traffic Manager provides you with a choice of load-balancing methods, including performance, fail-over and round-robin. By using these to effectively manage your traffic, you can ensure high performance, availability and resiliency of your applications.
- What are Traffic Manager "Health Checks"?
Traffic Manager enables you to improve the availability of your critical applications by monitoring your hosted Windows Azure service endpoints and providing automatic failover capabilities when a service goes down.
To do this, Traffic Manager continually monitors the health of each service endpoint. When these “Health Checks” detect that a service has gone down, Traffic Manager re-routes traffic to the other services.
- Are the prices the same for all load-balancing methods?
Yes, the prices for DNS queries and health checks are same irrespective of the load-balancing method being used.
- How can I reduce my Traffic Manager bill?
When an end-user's PC makes a DNS query, it doesn't contact the Traffic Manager name servers directly. Instead, these queries are sent via "recursive" DNS servers run by enterprises and ISPs. These servers cache the DNS responses, so that other users' queries can be processed more quickly. Since these cached responses don't reach the Traffic Manager name servers, they don't incur a charge.
The caching duration is determined by the "TTL" parameter in the original DNS response. This parameter is configurable in Traffic Manager—the default is 300 seconds, and the minimum is 30 seconds.
By using a larger TTL, you can increase the amount of caching done by recursive DNS servers and thereby reduce your DNS query charges. However, increased caching will also impact how quickly changes in endpoint status are picked up by end users, i.e. your end-user failover times in the event of an endpoint failure will become longer. For this reason, we don't recommend using very large TTL values.
Likewise, a shorter TTL gives more rapid failover times, but since caching is reduced the query counts against the Traffic Manage name servers will be higher.
By allowing you to configure the TTL value, Traffic Manager enables you to make the best choice of TTL based on your application's business needs.
Traffic Manager is available in the following regions:
|Geo ||Regions |
|United States || US East, US West, US North Central, US South Central |
|Europe || Europe North, Europe West |
|Asia Pacific || Asia Pacific Southeast, Asia Pacific East |
|Japan || Japan East, Japan West |
Support and SLA
Technical support for all Windows Azure services released to General Availability, including Traffic Manager, is available through Windows Azure Support, starting at $--/month. Billing and subscription management support is provided at no cost. Technical support is also available free of charge through community forums.
We guarantee that DNS queries will receive a valid response from at least one of our Windows Azure Traffic Manager name server clusters at least 99.99% of the time. Availability is calculated over a monthly billing cycle. To learn more about our SLA, please visit the SLA page.