Load balancers distribute network traffic across a number of servers. The distribution of a network's workload optimizes resource sharing and increases throughput and availability.
In Oracle Solaris, ILB provides Layer 3 and Layer 4 load-balancing capabilities. ILB operates at the network (IP) and transport (TCP/UDP) layers. ILB can be used to improve reliability and scalability, and to minimize the response time of network services.
The key features of ILB include the following:
Supports stateless Direct Server Return (DSR) and Network Address Translation (NAT) modes of operation for IPv4 and IPv6.
Assists traffic and load distribution and server selection by using a set of algorithms for the two modes of operation.
Enables ILB administration through the ilbadm command.
Provides server monitoring capabilities through health checks.
The following table lists and describes the features of ILB that are available for different modes of operation.
ILB is managed by the Service Management Facility (SMF) service svc:/network/loadbalancer/ilb:default. ILB has three major components:
ilbadm command-line interface (CLI) – Enables you to configure load-balancing rules, perform optional health checks, and view statistics.
libilb configuration library – Contains functionalities that ilbadm and third-party applications can use for ILB administration.
ilbd daemon – Performs the following tasks:
Manages persistent configuration across reboots and package updates
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 sends the results to the ILB kernel module so that the load distribution is properly adjusted