Configured and Operational VIPs are Out of Sync for GSLB Service

Issue & Symptoms

The following are the symptoms observed on Avi UI:

  • GSLB Services are in disabled state
  • Synchronization issues observed between two GSLB sites

Avi UI exhibits the reason for the disabled state as Configured and operational VIPs are out of sync as shown below.

gslb

Reason

This issue is observed when the virtual IP of a local virtual service of a GSLB pool of only one of the site is changed. The global application arrives to a state wherein the configured and operational GSLB pool member VIPs are out of sync (inconsistent).

Inconsistency

An Avi GSLB pool member is an Avi virtual service (with associated IP address:port_number). Configuration of such a member is performed using the site-id, the virtual service within the site, and the corresponding IP address of the virtual service. The relevant parameters are:

  • GslbPoolMember.site-cluster_uuid
  • GslbPoolMember.virtual-service_uuid
  • GslbPoolMember.ip in the GslbPoolMember object

For more information on these parameters, refer to the GSLB section of the REST API Guide.

Scenario 1

The following are the set parameters of a GSLB member:

  • site-cluster_uuid_W
  • virtual-service_uuid_X
  • ip-Y

These values represent the configured as well as operational state of the virtual service. Avi Vantage’s GSLB configuration is in sync with the virtual service locally defined by and operational at site W.

Scenario 2

When the administrator of site W changes Avi Vantage’s local configuration of the particular virtual service such that its VIP is now ip-Z.

When the IP address is changed from ip-Y to ip-Z for the site W. Since these changes are local so the VIP ip-Z is operational but, its address is not (yet) known to the GSLB configuration. It is no longer advertised to the other site and references to ip-Y are invalid. The GSLB leader and active members detect the discrepancy between the Scenario 1 VIP (ip-Y) and the Scenario 2 VIP (ip-Z). Avi Vantage then disables the GSLB pool member in question and notifies the error as Configured and Operational VIPs are out of Sync.

Resolution

Using Avi CLI

The below commands exhibit the scenario 1 and the scenario 2 steps in which the GslbPoolMember object is first configured, and then re-configured. “W,” “X,” “Y,” and “Z” are values for the demonstration purpose.

[admin:10-10-24-207]: > configure gslbservice gs-1
[admin:10-10-24-207]: gslbservice> groups
New object being created
[admin:10-10-24-207]: gslbservice:groups> name gs-11
[admin:10-10-24-207]: gslbservice:groups> members
New object being created
[admin:10-10-24-207]: gslbservice:groups:members>
[admin:10-10-24-207]: gslbservice:groups:members> cluster_uuid W
[admin:10-10-24-207]: gslbservice:groups:members> vs_uuid X
[admin:10-10-24-207]: gslbservice:groups:members> ip Y
[admin:10-10-24-207]: gslbservice:groups:members> save
[admin:10-10-24-207]: gslbservice:groups>

Perform the following steps to remove the inconsistency caused by locally changing ip-Y to ip-Z.

[admin:10-10-24-207]: > configure gslbservice gs-1
[admin:10-10-24-207]: gslbservice> groups index 1
members index 1
[admin:10-10-24-207]: gslbservice:groups:members>
[admin:10-10-24-207]: gslbservice:groups:members> ip Z
[admin:10-10-24-207]: gslbservice:groups:members> save

Using Avi UI

Use the GSLB Pool editor to delete the member virtual service (e.g., VS-Site-US-East in the below screenshot) and then add it back. The act of re-specifying values for the site cluster Controller and virtual service fields will cause Avi Vantage to query the Avi site for the new IP address.

Screen Shot 2017-01-19 at 6.32.09 PM