Amer Networks E5Web GUI - Manual (Page 691)

Figure 10.11. Stickiness and Round-Robin
If the connection-rate algorithm is applied instead, R1 and R2 will be sent to the same server
because of stickiness, but the subsequent requests R3 and R4 will be routed to another server
since the number of new connections on each server within the Window Time span is counted in
for the distribution.
Figure 10.12. Stickiness and Connection-rate
Regardless which algorithm is chosen, if a server goes down, traffic will be sent to other servers.
And when the server comes back online, it can automatically be placed back into the server farm
and start getting requests again.
10.4.5. SLB Server Monitoring
SLB Server Monitoring can be used to continuously check the status of the servers in an SLB
configuration. If monitoring is enabled and a server goes offline, cOS Core will not open any new
connections to that server until monitoring indicates that the server is online again.
The SLB Monitoring feature is similar in concept to the host monitoring feature used for the cOS
Core Route Failover feature and which is described in Section 4.2.4, “Host Monitoring for Route
Failover”. However, there are important differences.
Enabling Server Monitoring
Server monitoring is enabled on a per SLB rule basis with the list of servers to be monitored and
their IP addresses being already defined in each SLB rule.
Monitoring is turned on for an SLB rule by enabling polling through any one or any combination
of the three methods described below. A routing table is also specified for monitoring, with main
as the default, and this is the table used by polling to look up the server IP addresses. (This means
Chapter 10: Traffic Management
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