How It Works

The Incapsula global CDN acts as a dedicated load balancer for your website or application. Traffic is distributed across multiple servers within your data center according to a user-defined distribution policy.

All routing changes occur on the CDN level without TTL-related delays, while continuous monitoring and configuration options provide additional control.

Application Layer Local Server Load Balancing

Application layer load balancing provides maximum visibility into site visitor traffic. HTTP/S requests to each server are monitored and analyzed instantaneously, guaranteeing highest performance and optimal resource utilization. Unlike DNS load balancing, routing changes are not TTL-reliant and are instantly applied to all users.

Application Layer Local Server Load Balancing

Control and Visibility

Dashboards enable an up-to-the-second view of all traffic, to let you verify proper load distribution at all times. The live view also helps you identify and respond to developing issues, before they impact performance.

Control and Visibility

Choice of Distribution Methods

You can choose between several load distribution methods, including round robin distribution and advanced options based on networking factors (e.g., server load and connection times).

Session stickiness ensures that the same HTTP session always returns to the same preferred server.

Supported load distribution methods include:

  • Least pending requests – Next request is routed to the origin server with the smallest number of pending HTTP requests.
  • Least open connections - Next request is routed to the origin server with the smallest number of open TCP connections.
  • Source IP hash – A hashing function persistently maps a visitor’s IP address to one of the origin servers.
Choice of Distribution Methods

Health Monitor and Failover

Incapsula helps ensure your application or website is always accessible by monitoring your web servers and data centers. Notification capability ensures you are informed of any server availability issue.

Web server monitoring is performed using:

  • Passive monitoring that tracks availability based on server responses.
  • Active monitoring that proactively sends health check requests to web servers.
Health Monitor and Failover