Load Balancing Configuration; Real-Time Server Status Information - Coyote Point Systems E350GX Installation And Administration Manual

The table below summarizes the basic capabilities of the cluster types supported by Equalizer.
Feature
Load balancing
policies
Server failure
detection (probes)
Persistence
Server selection by
request content
(i.e., Match Rules)
Load balanced
protocols
NAT and spoofing
a. Note that some LDAP/LDAPS implementations are UDP-based.
Regardless of cluster type, Equalizer uses intelligent load balancing algorithms to determine the best server to
receive a request. These algorithms take into account the configuration options set for the cluster and servers, real-
time server status information, and information from the request itself. For Layer 7 clusters, user-defined match
rules can also be used to determine the route a packet should take.

Load Balancing Configuration

When you configure a virtual cluster, you can select one of the following load-balancing algorithms to control how
Equalizer balances the load across your servers:
,
connections server agent
When you configure the servers in a virtual cluster, you assign an initial weight between 0 and 200 for each server.
When you select one of the adaptive load-balancing algorithms (i.e., any algorithm other than round robin),
Equalizer uses the servers' initial weights as a starting point to determine the percentage of requests to route to each
server. Each server handles a percentage of the total load based on its fraction of the total weights in the server
cluster. Equalizer dynamically adjusts server weights according to real-time conditions to ensure that Equalizer
routes requests to the server that is best able to respond. A server with a weight of zero (0) is considered down or
unavailable, and Equalizer does not route requests to servers in this state.

Real-Time Server Status Information

Equalizer gathers real-time information about a server's status using ICMP Probes, TCP Probes, Active Content
Verification (ACV), and Server Agents. ICMP and TCP Probes are the default probing methods.
Equalizer Installation and Administration Guide
L4 UDP
round robin, static weight, adaptive, fastest response,
least connections, server agent, custom
ICMP, TCP, Server
Agent
Based on IP
No; load is balanced according to
current load balancing policy.
Ideal for
stateless UDP-
Ideal for stateful
based protocols,
such as DNS and
protocols, such
RADIUS; WAP
as HTTP, HTTPS,
gateways; NFS
server clusters
LDAP/LDAPS
that provide a
single-system
image.
round robin
, or .
custom
Cluster Type
L4 TCP L7 HTTP
ICMP, TCP, ACV, Server Agent
Yes; load is balanced according to
decisions made by examining request
TCP-based
SMTP, FTP,
a
and others.
Yes
, ,
static weight adaptive
Introducing Equalizer
L7 HTTPS
Using Cookies
content.
HTTP HTTPS
, ,
fastest response least
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