Microsoft has introduced new Basic Compute Tier pricing on Azure that offers savings of up to 27% when compared with General Purpose Tier Virtual Machines (VMs) to help customers benefit from savings when transitioning to IaaS. The new Basic Tier matches the General Tier options exactly in terms of compute and memory, but Basic Tier instances do not include Azure load balancer and auto-scaling options. For Azure customers who have requirements for application load balancing and L7 application delivery services when using Basic Tier VMs, an external load balancer is required.
KEMP Technologies built a specialized virtual load balancer optimized for Azure (Virtual LoadMaster (VLM) for Azure) that was released in summer 2013. It provides full Layer 7 load balancing, reverse proxy and advanced application delivery services. Additionally, it can be used for both Standard and Basic Tier VMs.
Application Delivery vs. Layer 4 Load Balancing
Load balancers typically operate at either Layer 4 (transport) or Layer 7 (application) of the network stack. Layer 4 load balancing only takes into account network attributes such as source port/address, destination port/address and protocol (TCP/UDP). This approach, while suitable for certain application deployments, can result in client traffic being directed to different servers during a single session and also limits the amount of traffic manipulation that can be done to encrypted application streams since SSL decryption is not possible at Layer 4. These factors may place extra complexity on many traditional applications that a customer wants to migrate to the cloud without much development effort since a client’s context has to be kept across all servers and advanced functions all have to be handled within the application.
KEMP’s Virtual Load Master for Azure complements the native functionality of Azure by providing all of the same features and functionality available on VLMs for private cloud including SSL offloading, pre-authentication and SSO, hybrid traffic distribution and services for multi-tenant applications such as intelligent content switching and SNI (server name indication). All of these services ensure that clients receive the best application performance and user experience possible.
In addition to services to enhance application performance, a core requirement of load balancers is to provide a mechanism for resilience and high availability of deployed applications. KEMP’s VLM monitors the health of servers and application resources and dynamically redirects traffic in the event of instance outages or reduced capability ensuring continuity of service to clients. For maximum availability, KEMP VLMs can also steer traffic across Azure-hosted and private clouds.
KEMP’s VLM for Azure is available via Microsoft’s VMDepot, so you can see for yourself how your application availability can be enhanced with KEMP and the lower cost Azure Basic Compute tier. To learn more, visit https://kemptechnologies.com/solutions/microsoft-load-balancing/loadmaster-azure.
|Azure Load Balancer||KEMP VLM for Azure|
|Application-Aware L7 load balancing||No||Yes|
|High Availability||Yes using Traffic Manager||Yes using GEO|
|Hybrid Traffic Distribution||No||Yes using GEO|
|Scheduling methods||Round Robin Only||L4 / L7|
|Server persistence||No||L4 / L7 (Cookie and more)|
|VM Resource Availability Awareness||No||Yes|
|Basic Tier VM Load Balancing||No||Yes|
|Least Connection Scheduling||No||Yes|
|Standard Tier VM Load Balancing||Yes||Yes|