Access GigaVUE-FM Active Instance in case of Failover

In a GigaVUE-FM high availability environment, GigaVUE-FM and device configurations can be performed only from the active GigaVUE-FM instance. Standby instances provide minimal configuration options. In case of failover, it is important to be aware of the IP addresses of the three GigaVUE-FMs and also the DNS host names of the GigaVUE‑FM instances so that you can access the active GigaVUE‑FM instance .

To overcome this restriction and still access the GigaVUE‑FM instances, you can use one of the following options:

• Use External Load Balancer
• Assign a DNS Name for the GigaVUE‑FM instances
• Use a Virtual IP address when all three GigaVUE-FM Instances are within the same subnet. Refer to the GigaVUE‑FM High Availability

Starting from software version 5.13.00, GigaVUE‑FM has an internal load balancer that takes care of the following tasks:

• Forwarding the application traffic to the appropriate GigaVUE-FM instances in the High Availability group.
• Load balancing the API GetRequests across the GigaVUE-FM instances for better load distribution.

Use External Load Balancer

Load balancer distributes traffic across a number of servers. Integrating a load balancer with GigaVUE‑FM, forwards the traffic to the active GigaVUE‑FM instance. Load balancer performs healthcheck of GigaVUE‑FM and forwards the traffic destined to the external GigaVUE‑FM IP address and thereby to the GigaVUE-FM high availability group.

To use load balancer for forwarding the traffic, you must ensure to do the following:

• Deploy the load balancer.
• Configure the load balancer to access the active instance in the GigaVUE-FM High Availability group. This is accomplished using the following GET API endpoint exposed by GigaVUE-FM:

https://<FM-IP>/api/v1.3/fmHa/status

Based on the returned response codes, the load balancer can be configured in such a way that healthy servers (active instance) are those that return 200 as response code when the endpoint API is queried. The remaining servers are considered as unhealthy servers (standby instances). With these configurations, the requests are forwarded to active GigaVUE-FM always.

Sample Response for GET https://<FM-IP>/api/v1.3/fmHa/status

If FM Role == Leader,

return 200 with Payload {"role" : "Leader" }

 

Else if FM Role == Standby

return 201 with Payload {"role" : "Standby" }

Else

return 4XX with Payload for 4xx {"role" : "Unknown" }

 

Note : 5xx can be thrown if the API Gateway on FM is not available/down

• Configure the load balancer with external GigaVUE-FM IP address as the DNS IP, for example, myfm.com.

Note:  If you add or remove the nodes in the GigaVUE-FM HA group, you must ensure to update the corresponding IP addresses of the nodes in the load balancer.

Assign DNS Name for the GigaVUE-FM IP 

You can assign a DNS name to the three GigaVUE‑FM IP addresses, which helps to access the GigaVUE-FM instance in case of failures. Consider a DNS name, myfm.com that has the IP addresses of the three GigaVUE‑FM instances of the high availability group.

If you type the DNS name of the GigaVUE-FM, myfm.com, the DNS server returns the IP addresses of the three GigaVUE‑FM instances, and:

• the Dashboard page of the active GigaVUE-FM instance appears, or
• the High Availability page of the standby GigaVUE-FM instances may appear f the active instance is not reachable, as in the case of a failover. From the High Availability page of the standby instance, you can navigate to the GigaVUE‑FM active instance.

This ensures that the GigaVUE-FM High Availability group is always accessible.