NETSCOUT Visibility to Avoid Outages in Load Balancing Environments

Improve the performance of your essential services across IT environments.

NETSCOUT Visibility to Avoid Outages in Load Balancing Environments

Load balancers typically sit at some of the most critical positions in your network—often serving as the initial digital point of contact for customers, employees, and service environments. This strategic role, however, comes with its own set of challenges. Modern applications are diverse and complex, and they can present new and sometimes frustrating load balancing challenges. Requests between clients and servers need to function according to each application’s specific requirements. When network and application outages happen, they can be a nightmare for IT organizations to troubleshoot without sufficient network performance monitoring. This can significantly affect the quality of experience (QoE) of an application. But monitoring any application, especially on-premises, isn’t very different from monitoring anything else, right? Well. . . 

Understanding Load Balancer Dynamics

IT organizations are increasingly dependent on load balancers to help them control application availability, delivery, and traffic flow. Most data center architectures, for example, include a load balancer layer between clients and the services they connect to, presenting a constant potential point of failure that could render multiple applications or services unavailable. Inside each load balancer lies a sophisticated algorithmic approach to traffic distribution. These systems, whether hardware- or software-based, leverage load balancing algorithms such as round robin, least connections, or IP hash to intelligently allocate incoming requests across a pool of servers. This optimization ensures equitable resource utilization and mitigates the risk of individual servers being overburdened.

Organizations implement a variety of load balancing strategies for their applications, tailoring them to meet specific objectives. Consider search engines and real-time unified communications and collaboration platforms such as Webex: They lean toward prioritizing low latency to accommodate high throughput and large-scale requests. E-commerce platforms may opt to prioritize high availability and stability for seamless shopping experiences. In multitier applications, there may be a load balancer in front of each application tier. Also, it is not just the load balancers in the first tier of an application that is crucial, but also any load balancers in the lower tiers supporting that application.

Solving Visibility Gaps

Maintaining optimal traffic flow requires addressing visibility gaps, sometimes called blind spots, at highly granular levels in real time. Load balancers, like any network component, are subject to gaps in visibility, where certain parts or aspects of a network’s traffic or activity are not adequately monitored or accessible for analysis. As with many networking devices, equipment health is addressed by vendor tools for management and configuration. While this is important, it often misses the performance of the applications passing through the device. This lack of visibility can hamstring an IT organization’s ability to completely understand what is happening in the network and exacerbate problems with application performance, leading to prolonged slowdowns, dropped requests, server crashes, and even service outages.

Solving visibility gaps often involves deploying vendor-independent, proactive, packet-level monitoring instrumentation to capture and analyze data packets traversing networks. By doing so, organizations can enhance their understanding of network traffic; monitor the performance of and through load balancers; and improve application efficiency, availability, and security. A dual-sided monitoring approach, covering both pre- and post-balancing stages, becomes a tactical imperative to bridge these gaps effectively.

The Significance of Dual-Sided Monitoring

As digital transformation initiatives give rise to increasingly software-centric services and evolved network designs, organizations can employ various methods to monitor load balancer performance, analyze traffic patterns, and troubleshoot issues related to both load balancing and user experiences. For example, comprehensive traffic management requires visibility on both the client and application (aka server) sides of load balancers (see Figure 1 for a simple example). The client side, representing user interactions, requires meticulous scrutiny to preemptively identify and resolve potential issues. On the application side, monitoring is essential to ensure each server in the pool is operating optimally.

  • Client-side monitoring: In-depth examination of client-side metrics includes evaluating DNS resolution times, SSL handshake durations, and the overall time taken for the initial connection setup. This level of granularity allows for a proactive approach to user experience optimization.
  • Application-side (server-side) monitoring: Metrics on the server side encompass server response times, error rates, and resource utilization. Detailed server-side monitoring involves tracking server health, ensuring that no single server becomes a performance bottleneck and distribution of traffic is rebalanced to overcome server unavailability.


Figure 1
Figure 1

In load balancing, “one-armed“ has both traffic types share a single interface, while “two-armed“ uses separate interfaces. Monitoring these configurations is crucial for optimizing traffic flow based on specific network requirements and architecture. Learn more in our white paper.


By strategically addressing both client and server aspects, organizations enhance their ability to fine-tune load balancing operations and optimize user experiences.

Monitoring Load Balancing Environments with NETSCOUT

NETSCOUT nGenius Enterprise Performance Management solutions provide comprehensive monitoring capabilities, offering visibility into network performance, application behavior, and security. NETSCOUT’s real-time deep packet inspection helps organizations quickly pinpoint and troubleshoot visibility gaps and improves mean time to repair (MTTR) of root causes such as bottlenecks, slowdowns, degradations, and security threats in the most complex distributed environments, ensuring reliable load balancer health and service quality.

Let NETSCOUT help you identify the most effective ways to maximize the instrumentation in your load balancing environments and prevent business disruptions.

Read this use case to see how—in 15 minutes—an IT organization at a large insurance provider resolved a near-total network outage in its core data center due to load balancer degradations.


Watch our on-demand webinar “Improving Load Balancer Performance with Network and Application Visibility“ by Eileen Haggerty (AVP) and Anthony Cote (senior manager) for NETSCOUT Product and Solutions Marketing. Learn about visibility gaps, load balancer performance monitoring, and how nGenius Enterprise Performance Management solutions can improve MTTR and user experience.