Avoiding network downtime that could kill your business? It's easy as ADC

A recent survey carried out by Freeform Dynamics on behalf of Barracuda Networks highlighted increasing pressure on corporate networks and the systems they support. When asked about their network and application access infrastructure respondents cited greater demands as a result of core business growth and a general increase in the use of technology and information within the business.

Overlaid on this is the additional pressure arising from home and mobile working, BYOD, and greater access of IT systems by customers, partners and suppliers.

Unfortunately respondents also admitted that difficulties keeping up with these pressures are negatively impacting the business and, with no sign of the growth in traffic or the appetite for broader access diminishing, keeping up with the trends is proving hard. Specific challenges reported include:

• Poor/unpredictable application performance and unplanned outages, which undermine productivity and even interrupt the business
• Changing access patterns, a range of external threats, and the unintended consequences of virtualisation are all hampering the management of security in particular
• Many also cite excessive costs to the business

Whether an organisation has an ecommerce site or provides services that are dependent on information delivered through web applications, optimal application performance is critical for success.

However, when user traffic spikes and servers are bogged down by large data file requests, memory overloads, and hackers attempting to flood servers, site and application performance can slow or grind to a halt. And when users can't access a company's applications or they experience long waits, network downtime can kill a business (at least for a time).

While it is easy to throw more hardware at the problem, this is not always the best strategy when traffic isn't properly directed to the best performing resource. Nor is it economical for many businesses.

So how do IT managers ensure web and application uptime and speed to get optimal performance out of data centre equipment – while keeping costs to a minimum?

Step forward ADCs

ADCs (application delivery controllers) provide a set of functions to optimise enterprise application environments. The market evolved from the load-balancing systems that were specifically developed to ensure the availability and scalability of websites. Enterprises use ADCs to optimise reliability, end-user performance, data centre resource use and security for a variety of enterprise applications.

Why businesses need ADCs

The costs of ensuring high web application infrastructure availability, performance access and speed, and secure operations can be dramatically reduced using ADCs and server load balancers.

Benefits of ADCs

1. Improve performance by distributing traffic among multiple servers – server load balancing is the basic functionality of ADCs. By accepting traffic on behalf of servers, ADCs select a server to which they will forward that traffic. For example, if there are two servers that are substantially different in performance capacities, you can designate the higher performing server with a higher "weight" (more traffic).

2. Optimise resources by efficiently allocating traffic based on application types – content switching is a higher level load balancing method that enables an ADC to decide where to send traffic based on information in the request. For example, an ADC can send all graphics or multimedia-type requests to a group of optimised servers, while other requests can be sent to servers optimised for transaction processing. By dedicating your servers, they become more efficient in increasingly specialised tasks, providing for greater performance tuning and application flexibility.

3. Ensure application and data-access consistency – when deploying load balancers or ADCs, it is important for some types of applications to maintain "stickiness" to a single server to ensure that the application session is completed. An example is an online shopping cart. If during the session the customer is switched to a server that does not contain shopping cart data for that user, the shopping cart will be lost – as well as potentially the final sale.

4. Improve user experience and reduce server overhead with SSL acceleration – if your site contains transactional elements, you likely use SSL to encrypt and secure those transactions. SSL accelerators remove the workload away from servers and place the burden on the ADC. This significantly increases the performance processing of SSL traffic while simplifying SSL certificate management.

5. Reduce single points of failure – the ADC performs health checking on the servers and automatically takes a server (or application on that server) offline if it has been deemed unresponsive or fails. Employing an ADC solution to ensure proper traffic management and optimise web and application performance is one way to stay ahead of the curve – and avoid the downtime that can severely damage a company.

Lack of awareness

The relatively low level of current use and future attention on ADCs revealed by the research probably reflects a general lack of awareness and understanding of the potential value offered by multi-function appliances. This is not surprising given that this type of solution is a comparatively new entrant in the market and is often associated with complex and demanding environments.

However, as ADCs become more 'mainstream', those with experience confirm the associated benefits they deliver in terms of infrastructure simplification and lowering of overheads, as well as reducing the risk of things falling through the cracks. A relatively small investment in ADCs now might just be the ticket to the long-term improvement, scalability and performance of increasingly diverse networks.

• Wieland Alge is General Manager EMEA at Barracuda Networks