ArcGIS Enterprise HA without a load balancer

[JoeHershman]

I find the documentation a bit confusing on this topic.

Is it possible to implement an HA Enterprise deployment using only Web Adapter and not a 3rd party load balancer?  If so where is documentation for this 

@JonathanQuinn 

Personally, I do not see how Web Adapter is setup in front of two Portal machines.

[JoeHershman]

I am not an infrastructure guy.  One client uses an F5, which I do believe is one of the top brands on the market, and not cheap.

We are in process of trying to do an approach without a load balancer and to use Windows Failover clustering as a less expensive approach.  This is on-going effort.

[LanceKirby2]

Geez that's is expensive! Thank you for helping me out. I guess my take away is yeah you can use web adaptors and they will route requests between each server if one is busy, but if one is handling a request and fails that request is just dead in the water and not routed to the other running server. If there was a third party load balancer in place, it would route requests just like web adaptor, but in the case where a request fails it would send that over to the running server. So to really have high availability you need a third party load balcncer.

I imagine this is a real issue with long running async requests, but for something like a query the user may not notice it as much. Would you agree with that?

[JonathanQuinn]

It is possible to set up an HA deployment without a load balancer. The Web Adaptor acts as a load balancer; actively checking the health of the machines in the site its registered to, using simple a round-robin method to send requests to backend machines, and only sending requests to healthy machines. However, its a single point of failure which is generally why we suggest a load balancer in front of two web adaptors.

The Web Adaptor is really only necessary if you're using Integrated Windows Authentication, so if that's the case, you'd want to minimize single points of failure by setting up two. Whether they're behind a load balancer, or in a failover cluster where one Web Adaptor instance is active and the other standby in the event the active one goes down, is up to the organization and the resources available to it.

We can look into updating the documentation related to Windows Failover Cluster and similar approaches in place of a load balancer.

[LanceKirby2]

@JonathanQuinn Thanks for your response! Additional documentation would be highly appreciated.