Radware Alteon User Manual

Alteon Application Switch Operating System Application Guide
Server Load Balancing
188 Document ID: RDWR-ALOS-V2900_AG1302
Example Real server groups using another real server group for backup
Backup Preemption
Alteon supports control preemption of backup when a primary server becomes active.
To enable or disable backup preemption
By default, preempt is enabled. When the primary server becomes active, it displaces the backup
server and takes control. When preempt is disabled, the backup server continues processing
requests sent by Alteon even if the primary server becomes active. During this process, the primary
server is operationally disabled and becomes active only if the backup server goes down.
In the following example, Real Server 4 is configured as backup for Real Server 1, and preemption is
disabled in Real Server 1:
Server Slow Start
Server slow start is an optional service that can be implemented on new real servers. The primary
purpose of this service is to avoid sending a high rate of new connections to a new server. When the
slow start begins, traffic is throttled and increased gradually until server initialization is complete.
Server slow start is controlled by setting a time limit that determines the length of the slow start
period. Server slow start begins when any of the following occur:
• Server comes online
• A new real server is added and comes online
• Multiple real servers are in a slow start mode
Server slow start ends when any of the following occur:
• The server slow start time limit expires
• The new real server metric weight reaches its target value
Server slow start is enabled on a group level to all real servers in that group.
>> # /cfg/slb/group <real server group
number>
(Select real server group)
>> Real server group# backup g2
(Assign Real Server Group 2 as backup)
/cfg/slb/real <server number>/preempt e|d
>> # /cfg/slb/real 4
(Select Real Server 4 as backup)
>> Real server 4# rip 200.200.200.5
(Assign backup IP address)
>> Real server 4# ena
(Enable Real Server 4)
>> Real server 4# /cfg/slb/real 1
(Select Real Server 1)
>> Real server 1# backup 4
(Real Server 4 is backup for 1)
>> Real server 1# preempt dis
(Disable preemption ability of real 1))

Radware Alteon Specifications

General

Model	Alteon
Manufacturer	Radware
Layer	Layer 4-7
Type	Application Delivery Controller (ADC)
Features	Load balancing, SSL offloading, application acceleration, DDoS protection
Form Factor	Virtual Appliance