Integrated Load Balancer Overview

Integrated Load Balancer (ILB), a feature of Oracle Solaris, provides Layer 3 and Layer 4 load-balancing capabilities for Oracle Solaris installed on SPARC and x86 based systems. ILB intercepts incoming requests from clients, decides which back-end server should handle the request based on load-balancing rules, and then forwards the request to the selected server. ILB performs optional health checks and provides the data for the load-balancing algorithms to verify if the selected server can handle the incoming request.

This chapter discusses the following sections:

• ILB Terminology

• Features of ILB

• ILB Processes

• Guidelines for Using ILB

• ILB and the Service Management Facility

• ILB Command and Subcommands

The key features of ILB include:

• Support for stateless Direct Server Return (DSR) and Network Address Translation (NAT) modes of operation for IPv4 and IPv6

• Allows ILB administration through a command-line interface (CLI)

• Provides server monitoring capabilities through health checks

ILB has three major components:

• ilbadm CLI – You can use this interface to configure load-balancing rules, perform optional health checks, and view statistics.

• libilb configuration library – ilbadm and other third-party applications can use the functionality implemented in libilb for ILB administration.

• ilbd daemon – This daemon performs the following tasks:

  • Manages persistent configuration

  • Provides serial access to the ILB kernel module by processing the configuration information and sending it to the ILB kernel module for execution

  • Performs health checks and notifies the results to the ILB kernel module so that the load distribution is properly adjusted