Azure – Networking – Part 18 – Azure Traffic Manager 1
I hope everyone fully enjoyed their new year vacation :). So all are now with fresh mind. Today let’s pick one of the very very important Azure networking service and that is Azure Traffic Manager. Our last article was on ” VNet Peering ” . In this journey we will go through the basics of Azure Traffic Manager , which I have collected from different sources like from Microsoft articles,other blogs and videos . I have summarize important points in this article. So Let’s Start our new journey.
If you have missed our previous articles on azure networking, please check it in following links.
Azure Traffic Manager :
AS I said Azure Traffic Manager is one of the very critical/ useful service provided by MS Azure. Traffic Manager provide us DNS-based load balancing ability, which enables us to distribute traffic optimally to services across global Azure regions, while providing high availability and responsiveness. Azure provides a suite of fully managed load-balancing solutions for our scenarios.
How Does Azure Traffic Manager Work :
Azure Traffic Manager enables us to control the distribution of traffic across our application endpoints. An endpoint is any Internet-facing service hosted inside or outside of Azure.
Traffic Manager works at the DNS level. It uses DNS responses to direct clients to the appropriate service endpoint. Clients then connect to the service endpoint directly, not through Traffic Manager. Traffic Manager does not see HTTP traffic between client and server.
Routing Methods Of Azure Traffic Manager :
Performance : Routing method performance is designed for endpoints in different geographic locations and we want end users to use the closest endpoint in terms of the lowest network latency
Priority : Priority method is designed to root all user traffic based on Priority.
Weighted : This routing method designed to distribute traffic across a set of endpoint, Either evenly or according to weight, which we defined.
Geographic : This geographic method is designed in a way so that users are directed to specific endpoints (Azure, External, or Nested) based on which geographic location their DNS query originates from.
Multi-value :This method getting multiple healthy endpoint in a single DNS query.
Subnet : Subnet method allows for mapping map a set of user IP address ranges to specific endpoints in a profile.
One Traffic Manager profile can use only one traffic routing method in a single point of time. We can change to a different traffic routing method for our profile at any time. Changes are applied within one minute, and no downtime is incurred.
Real User Measurements :
Real user measurement is a small concept in Traffic Manager, which helps traffic manager to improve it’s decision taking ability. Real User Measurements enables us to measure network latency measurements from end user application to Azure regions, and Traffic Manager consider that information as well when making routing decisions. following are few more information about Real User Measurements .
- We can use Real User Measurements also with non-Azure regions.
- Real User Measurements are applicable only for profiles that use the performance routing method.
- Enable Real User Measurements once per subscription and all the latency information measured and reported are available to all profiles.
- We can disable Real User Measurements by deleting our Real User Measurements (RUM) key .
- We can use Real User Measurements with client applications other than web pages.
Benefits Of Azure Traffic Manager :
- Distribution of traffic according to one of several traffic-routing methods.
- Increase application availability (Azure Traffic Manager includes built-in endpoint monitoring and automatic endpoint failover).
- Improve application performance .
- Perform service maintenance without downtime.
- Combine hybrid applications.
- Distribute traffic for complex deployments
Traffic Manager endpoints :
We can enable and disable endpoints of configured Traffic Manager. Traffic Manager supporting following three types of endpoints :
- Azure endpoints : This end points are used if we are using services hosted on azure ( e.g PaaS cloud services, Web Apps , Web App Slots, PublicIPAddress resources ).
- External endpoints : This end point are used for IPv4/IPv6 addresses, FQDNs, or for services hosted outside Azure.
- Nested endpoints : Nested endpoints are used to combine Traffic Manager profiles to create more flexible traffic-routing schemes to support the needs of larger, more complex deployments.
Traffic Manager Azure endpoints do not permit more than one Web App endpoint from the same Azure region to be added to the same Traffic Manager profile.
Traffic Manager Endpoint Monitoring
Azure Traffic Manager includes built-in endpoint monitoring and automatic endpoint failover. Which help us to deliver high-availability applications by checking the health of the endpoint and immediately switch to a different healthy available endpoint . Following major properties need to be configured, when configuring an end point monitoring as in following figure.
- Custom header settings
- Expected status code ranges
- Probing interval
- Tolerated number of failures
- Probe timeout
Traffic View And Metrics :
Traffic View is a feature of Traffic Manager that helps us to understand more about our users and how their experience is. It uses the queries received by Traffic Manager and the network latency intelligence tables that the service maintains. We can turn off Traffic View for any profile using the Portal or REST API. It provides following benefits:
- The regions from where our users are connecting to our endpoints in Azure.
- The volume of users connecting from these regions.
- The Azure regions to which they are getting routed to.
- Their latency experience to these Azure regions.
- Health of the end points.
Like from traffic view, we can also get additional information from Traffic Manager Metric. Traffic Manager provides some metrics on a per profile basis that customers can use to understand their usage of Traffic manager and the status of their endpoints under that profile.
Pricing Model for Traffic Manager :
Traffic Manager billing is based on the following pricing dimensions:
- The number of DNS queries received, with a discount for services receiving more than 1 billion monthly queries.
- The number of monitored endpoints. The rate depends on (1) whether it is an Azure or external service and (2) how frequently we want Traffic Manager to monitor the endpoint.
- The number of real user measurements received by the Traffic Manager service.
- The number of data points used to generate Traffic View outputs.
We can found more pricing details of Azure Traffic Manager from this Link. In our next article, we can see how to configure a Traffic Manger.
Hope this article helps you and in my next article, we will go through a simple hands-on and will see how traffic manager actually works :).
My next article of this series is Part 19 – Azure Traffic Manager 2 -Create Traffic Manager Profile using (Cloud Shell) .
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Thanks for reading 🙂 .