Radware Alteon User Manual

Alteon Application Switch Operating System Application Guide
Health Checking
506 Document ID: RDWR-ALOS-V2900_AG1302
Examples
A (1|2)&(3|4)
Real servers 1, 2, 3, and 4 are configured in group 1 and assigned to virtual service x in Virtual
Server 1. The boolean expression is used to calculate the status of a virtual service using group
1 based on the status of the real servers.
Virtual service x of Virtual Server 1 is marked UP if Real Servers 1 or 2 and Real Servers 3 or 4
are health checked successfully.
B (1&2)|(2&3)|(1&3)
Real servers 1, 2, and 3 are configured in Group 2 and assigned to virtual service x in Virtual
Server 1. The boolean expression is used to calculate the status of the virtual service using
Group 2 based on the status of the real servers.
Virtual service x of Virtual Server 1 is marked UP only if at least two of the real servers are
health checked successfully.
Disabling the Fast Link Health Check
By default, Alteon sets the real server as operationally down as soon as the physical connection to it
is down, without waiting for the health check to fail. This behavior may not be advantageous in
certain configurations in which a link may go down and then be quickly restored, such as in VPN load
balancing. By disabling this "fast health check" behavior, the real server will be marked as down
only after the configured health check interval, thus allowing the possibility of the server
re-establishing itself before the next health check.
To enable or disable fast link health checks
>> # /cfg/slb/group 1
(Select the Real Server Group 1)
>> Real server group 1# advhlth (1|2)&(3|4)
(Configure a boolean expression for
health check)
>> # /cfg/slb/virt 1/service x/group 1
(Assign the Real Server Group 1)
>> Virtual Server 1 Service# apply
(Apply the changes)
>> Virtual Server 1 Service# save
(Save the changes)
>> # /cfg/slb/group 2
(Select the Real Server Group 2)
>> Real server group 2# advhlth (1&2)|(2&3)|(1&3)
(Configure a boolean expression for
health check)
>> # /cfg/slb/virt 1/service x/group 2
(Assign the Real Server Group 2)
>> Virtual Server 1 Service# apply
(Apply the changes)
>> Virtual Server 1 Service# save
(Save the changes)
>> # /cfg/slb/real <real-server-#> /adv/fasthc ena|dis

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