Has Something Gone Wrong?

Generally, we choose to leverage Read-Access Geo-Redundant Azure Storage Accounts (RA-GRS) because we can use it as part of our disaster recovery (DR) plan. And sometimes, we forget that our devil is in the details. Disaster recovery (DR) plans are rarely tested and can cause headaches when they are. So let’s relieve some of those headaches.

Headache…

“Geo Replication Lag” for GRS and RA-GRS Accounts is the time it takes for data stored in the Primary Region of the storage account to replicate to the Secondary Region of the storage account. Because GRS and RA-GRS Accounts are replicated asynchronously to the Secondary Region, data written to the Primary Region of the storage account will not be immediately available in the Secondary Region. Customers can query the Geo Replication Lag for a storage account, but Microsoft does not provide any guarantees as to the length of any Geo Replication Lag under this SLA.

The Recovery Time Objective (RTO) and Recovery Point Objective (RPO) are the first items that come up in DR discussions. When we use RA-GRS we control the RTO because we decide when to read from the secondary location. The RPO is a bit different because that can vary due to physics and load. The best way get current Recovery Point (RP) is to get the last sync time for the RA-GRS in question. This post is all about getting the right information, when we need it, because we need facts to make the right decisions.

Windows Azure Traffic Manager – High Performance, Availability & Resiliency

With the ability to deploy Windows Azure Cloud Services in different geographical locations, there has to be a way to bring it all together under a single URI.

The Windows Azure Traffic Manager does just that! It allows your end-user’s to interact with the cloud service instance that is closest to them! But that’s not all, it provides the ability 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. By effectively managing traffic, you can ensure high performance, availability and resiliency for your applications.

During Preview, Windows Azure Traffic Manager is currently available at no charge.

Available Traffic Manager Profiles

• Performance – Use this method when your endpoints are deployed in different geographic locations and want to use the one with the lowest latency.
  See Performance load balancing method in Windows Azure Traffic Manager
• Round Robin – Use this method when you want to distribute traffic equally across a set of endpoints.
  See Round Robin load balancing method in Windows Azure Traffic Manager.
• Failover  – Use this method when a primary endpoint is selected to serve all the traffic but backups are required in case the primary or the backup endpoint go offline. The endpoints can be in the same data center or in different data centers. See Failover load balancing method in Windows Azure Traffic Manager.