HP VPN Firewall Appliances High Availability Configuration Guide

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Figure 95 Relationship between the components of the server load balancing module
• Real service group—A group of real services.
• Real services—Entities that process services in a cluster (such as servers in Figure 84, and Figure 86,
and firewa
lls Figure 88. A real servi
ce group comprises multiple real services.
• Virtual service—A logical entity that faces users. For server load balancing and firewall load
balancing, a virtual service corresponds to one real service group.
Server load balancing operates in the following way:
1. After a user sends a request to the virtual service of the LB device, if a persistence method is
specified in the virtual service, and matched persistence entries exist, the request is distributed
according to the persistence entries. Otherwise, the virtual service obtains the information of the
related real service group, and then continues the following procedure. For more information
about persistence methods, see Table 17.
2. R
eal services are matched
against ACL rules specified in the real services one by one according
to the weights of the real services. Requests allowed by the ACL are distributed to the
corresponding real service; if requests are not allowed by the ACL or no matched real services
exist, the following procedure is continued.
3. Distributes the request to a real service in the group based on the algorithm configured in the real
service group.
Recommended configuration procedure
Ste
p
Remarks
1. Saving of the last hop information
Saving of the last hop information must be enabled on a level
2 LB device in firewall load balancing. This task is optional in
other cases.
For more information, see "Configuring public parameters."
2. Configuring a health monitoring method
A health monitoring method must be configured if you adopt
SSL health monitoring. This task is optional in other cases.
3. Creating a real service group
Required.
IMPORTANT:
The maximum number of real
service groups, real services, and
virtual services depends on the
resource configuration of the virtual
device. For more information, see
System Management and
Maintenance Configuration Guide
.
4. Creating a real service
Required.
Creating a virtual service for server load
balancing
Required.