Global load-balancing challenges
Maintainability, availability, and disaster recovery planning are critical elements in today’s Internet-driven industries. Progressive ebusiness companies must have IT infrastructures and business processes to assure IT systems maintain 100% availability, as downtime even in the order of minutes can mean the loss of tens of thousands in revenue dollars. These concerns are well understood in today’s advanced IT operations and successful companies continuously strive to address these needs. This holds true for customer-facing applications and infrastructure as well as internal applications within an enterprise.
One of the most important elements of an effective ebusiness infrastructure is global redundant web content distribution, which must include a reliable and scalable DNS infrastructure, to bring users to the web servers, and Global Server Load Balancing (GSLB) solutions to distribute and shape query responses with different geographically distributed data centers. Global Server
Load Balancing solutions have been an attractive tool in an ebusiness infrastructure because they solve a number of problems:
GSLB can be used as a disaster recovery tool, allowing automatic failover to alternative content servers in other data centers should there be an operational or technical failure, or a catastrophic event.
GSLB provides the ability to route users to content servers that are either geographically or (network) topologically close by.
GSLB can improve performance of the existing servers resources by preventing “busy” servers from overloading and increasing traffic to “less busy” servers, thus maximizing overall utilization of the content network.
Although the benefits of robust load balancing systems are easy to justify, the IT infrastructure equipment needed for it is costly to procure, deploy, and maintain. Today’s solutions to this problem include a variety of dedicated hardware/software solutions: public and private DNS name servers; local load balancers; http redirection systems, and higher-layer packet switching systems. The complexity of these hardware/software systems in some cases becomes burdensome as tangible and intangible costs are incurred, such as:
Capital expenditures to procure and replace the required equipment over a network’s life cycle
Costs associated with training new staff on the systems
Software upgrade costs
Annual licenses and maintenance contract costs
Extended downtime due to troubleshooting during outages due to the complexity of the environment and its dependencies
Many progressive IT administrators will investigate strategic outsourcing solutions for their infrastructure where it is practical and cost effective to meet business needs. GSLB solutions are provided by some Internet Service Providers (ISPs) and Content Delivery Network (CDN) providers, but are often bundled with other services. In this case the administrator has to make a compromise decision, possibly forcing a non-optimal outsourcing solution, or continuing to keep control of the GSLB capability in-house.