Configured and Operational VIPs are Out of Sync for GSLB Service

GSLB services are in a disabled state and a synchronization issue was observed between the GSLB site. Avi Load Balancer UI exhibits the reason for the disabled state as Configured and operational VIPs are out of sync.

Reason

It is both possible and reasonable to locally administer components of a GSLB application deployment. For example, a local site administrator may select to change the virtual IP of a local virtual service member of some GSLB pool. When doing so, the global application arrives at a state wherein the configured and operational GSLB pool member VIPs are out of sync (inconsistent). This inconsistency is a natural consequence and is automatically detected by Avi Load Balancer. This section details the inconsistency and offers steps by which to return to a consistent state.

How the Inconsistency Can Arise

An Avi Load Balancer GSLB pool member is an Avi Load Balancer virtual service (with associated VIP:port_number). Configuration of such a member requires the user to uniquely identify the site-id, the virtual service within the site, and the corresponding VIP of the virtual service.

The relevant parameters in the GSLB pool member objects are:

• GslbPoolMember.site-cluster-uuid

• GslbPoolMember.virtual-service-uuid

• GslbPoolMember.ip

Now consider the following scenario:

Day 1: The three parameters of the GSLB pool members are set to site-cluster-uuid-W, virtual-service-uuid-X and ip-Y. These values represent both the configured and operational state of the virtual service. The GSLB configuration (a global entity) is in sync with the virtual service locally defined by and operational at site W.

Day 2: For any reason, the administrator of site W changes the controller's local configuration of the particular virtual service such that its VIP is now ip-Z.

The situation: Though local VIP ip-Z is operational, its address is not yet known to the GSLB configuration. It is no longer advertised as part of the global app and references to ip-Y are invalid. The GSLB leader and active members detect the discrepancy between the Day 1 VIP (ip-Y) and the Day 2 VIP (ip-Z). The Avi Load Balancer then disables the GslbPoolMember in question and notifies the administrator that the Configured and Operational VIPs are out of Sync.

The resolution steps are given in the following section.