Application SLA: Knowing Is Half the Battle

by Radware on April 4, 2019

Applications have come to define the
digital experience. They empower organizations to create
new customer-friendly services,
unlock data and content
and deliver it to users at the time and
device they desire,
and provide a competitive differentiator over the competition.

Fueling these applications is the “digital core,” a vast plumbing infrastructure that includes networks, data repositories, Internet of Things (IoT) devices and more. If applications are a cornerstone of the digital experience, then managing and optimizing the digital core is the key to delivering these apps to the digitized user. When applications aren’t delivered efficiently, users can suffer from a degraded quality of experience (QoE), resulting in a tarnished brand, negatively affecting customer loyalty and lost revenue.

Application delivery controllers (ADCs) are ideally situated to ensure QoE, regardless of
the operational scenario,
by allowing IT to actively monitor and enforce
application SLAs.
The key is to understand the role ADCs play and the capabilities required to ensure the digital
experience across
various operational scenarios.

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Optimize Normal Operations

Under normal operational conditions, ADCs optimize application
performance, control and allocate resources to those applications and provide
early warnings of potential issues.

For starters, any ADC should deliver web performance optimization
(WPO) capabilities to turbocharge the performance of web-based applications. It
transforms front-end optimization from a lengthy and complex process into an
automated, streamlined function. Caching, compression, SSL offloading and TCP
optimization are all key capabilities and will enable faster communication
between the client and server while offloading CPU intensive tasks from the
application server.

Along those same lines, an ADC can serve as a “bridge” between the
web browsers that deliver web- based applications and the backend servers that
host the applications. For example, HTTP/2 is the new standard in network
protocols. ADCs can serve as a gateway between the web browsers that support
HTTP/2 and backend servers that still don’t, optimizing performance to meet
application SLAs.

Prevent Outages

Outages are few and far between, but when they occur, maintaining
business continuity is critical via server load balancing, leveraging cloud
elasticity and disaster recovery. ADCs play a critical role across all three
and execute and automate these processes during a time of crisis.

If an application server fails, server load balancing should
automatically redirect the client to another server. Likewise, in the event
that an edge router or network connection to the data center fails, an ADC
should automatically redirect to another data center, ensuring the web client
can always access the application server even when there is a point of failure
in the network infrastructure.

Minimize Degradation

Application SLA issues are most often the result of network
degradation. The ecommerce industry is a perfect example.
A sudden increase in network traffic
during the holiday season can result
in SLA degradation.

Leveraging server load balancing, ADCs provide elasticity by
provisioning resources on-demand. Additional servers are added to the network
infrastructure to maintain QoE, and after the spike has passed, returned to an
idle state for use elsewhere. In addition, virtualized ADCs provide an
additional benefit, as they provide scalability and isolation between vADC
instance at the fault, management and network levels.

Finally, cyberattacks are the silent killers of application performance, as they typically create degradation. ADCs play an integrative role in protecting applications to maintain SLAs at all times. They can prevent attack traffic from entering a network’s LAN and prevent volumetric attack traffic from saturating the Internet pipe.

The ADC should be equipped with security capabilities that allow
it to be integrated into the security/ DDoS mitigation framework. This includes
the ability to inspect traffic and network health parameters so the ADC serves as an alarm system to
signal attack information to a DDoS mitigation solution. Other interwoven safety features should
include integration with web application firewalls (WAFs), ability to
decrypt/encrypt SSL traffic and device/user fingerprinting.