As mentioned in the prior newsletter, this is the second of a three-part series in which our colleague Robin Layland is sharing insight from the just released “2010 Application Delivery Challenge“.
This time, Robin continues to share his ideas with us, defining the various components of a comprehensive Application Delivery Networking strategy.
“Application delivery servers are deployed using two separate solutions. The first is the Application Delivery Control or ADC for short. ADC evolved from a Server Load Balancing base that supports a wide range of applications. It also monitors the heath and response time of the server. When it notices a problem it alerts operations and can also take action, lessening the problem.
“ADC also offloads tasks for servers that can best be handled in special purpose hardware. A good example is SSL processing. SSL encryption and de-encryption are processor intensive tasks. Running them in a server’s general purpose processor is inefficient and takes valuable cycles away from running the application. Putting a specialized processor in every server is costly and inefficient since the process would be greatly underutilized. Centralizing the SSL processing in the ADC is the best answer. The ADC also reduces the server’s workload by reducing the number of short lived connections a server has to deal with. Additionally, the ADC also performs application acceleration functions such as caching common objects so that the ADC can quickly deliver them to the users. This also saves server resources since the server doesn’t have to expend its resources sending the object.
“The second component of an Application Delivery Networking strategy is a WAN Optimization Controller (WOC). A WOC is deployed in a symmetrical configuration. It performs advanced application acceleration and bandwidth optimization allowing it to significantly improve response times and reduce bandwidth requirements. Initially WOC focused on Web applications, file server protocols such as CIFS and CAD/CAM but recently has expanded its range of supported application protocols to include SharePoint, NFS, VDI and other leading application protocols. WOCs have also taken on the task of monitoring at the application layer. This monitoring complements the traditional network layer monitor and gives network operations a complete view of what is happening. Additionally, WOCs have added security and application servers functions. Just a few examples include support for DNS/DHCP, print servers, active directory and streaming media that greatly reduce costs at branch offices.
“Where do WOCs and ADCs need to be deployed? Just about everywhere. ADCs are a critical data center technology and are needed wherever large number of servers are deployed. WOCs are critical between data centers and remote offices but that is not the only location they are needed. They have an important role to play between data centers. Their ability to reduce bandwidth requirements and speed up processes make them a winner by significantly cutting the time and bandwidth it takes to perform backups, database replication and disaster recovery tasks between data centers. WOC vendors have also turned their solution into software that can be installed in PCs allowing traveling employees and telecommuters to gain the acceleration and WAN bandwidth reduction benefits.
“The final frontier for ADCs and WOCs is in the cloud. When enterprises use cloud computing or storage their ADCs and WOCs need to follow the data and applications into the cloud. It is important that users and customers receive the benefits of reduced response time provided by both ADCs and WOCs. They will need the power of ADC’s SLB and server monitoring functions at the cloud location along with the bandwidth reducing capabilities of WOCs.”
In the third and final portion of this series, we’ll look at key issues to consider when choosing a product or set of products to fulfill this strategy.
