Alteon Application Switch Operating System Application Guide
Server Load Balancing
Document ID: RDWR-ALOS-V2900_AG1302
187
Example
Real server groups using another real server group for
backup/overflow
Backup Only Server
Unlike a Backup/Overflow server, a Backup Only server is used to only backup real servers, and not
provide an overflow capability. This enforces maximum session capacity while still providing
resiliency. In this configuration, if the primary server reaches its maximum session capacity, the
backup server does not take over sessions from the primary server. The backup server only comes
into play if the primary server fails.
Example
Define Real Server 4 as a backup only server for Real Servers 1 and 2
Example
Assign a backup/overflow server to a real server group
Similarly, a backup/overflow server can be assigned to a real server group. If all real servers in a
real server group fail the backup comes online.
>> # /cfg/slb/group <real server group
number>
(Select Real Server group)
>> Real server group# backup r4
(Assign Real Server 4 as backup)
>> # /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 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# /cfg/slb/real 2
(Select Real Server 2)
>> Real server 2# backup 4
(Real Server 4 is backup for 2)
>> # /cfg/slb/group <real server group
number>
(Select real server group)
>> Real server group# backup r4
(Assign Real Server 4 as backup)