cloud,cluster-computing,load-balancing,coreos , How does CoreOS load balancing work out there in the wild on a cloud service?

How does CoreOS load balancing work out there in the wild on a cloud service?


Tag: cloud,cluster-computing,load-balancing,coreos

Say I have a CoreOS cluster deployed on some cloud service somewhere.

Now I have, say, 4 machines running a node.js app which follows all the 12-factor tenets and one machine with Couchbase.

How does load balancing work in this scenario? Wouldn't ONE ip eventually run out of juice as a load balancer or is that pretty much impossible? Where do I point the DNS for it to work right?

In the past I had one IP with NGINX upfront, which then directed the incoming requests round-robin style.

How does this work with a CoreOS on a cloud service?


There are different approaches to achieve such task. In general, there should be cloud service load balancers in front of your infrastructure, clusters or datacenters. You will be dealing with two or three tier architectures.

The DNS points to your cloud internet-facing load balancer, which manages the client tier layer in any case. In the case of AWS, it must be through a CNAME record.

Auto scalable groups for each tier would potentially mitigate the risk of reduced availability of your infrastructure. Then, The Nginx instances are configured through cloud-config in case provisioning from bootstrap stage is required.

  1. Two tier architecture (your scenario)

    Each Nginx instance listens to an HTTP port and uses upstreams to do the routing (depending on your NodeJS apps distribution). The service discovery is achieved through etcd, using Registrator + SkyDNS / Consul or Weaver, so instead of upstreams, the Nginx resolver could be replaced by the internal DNS provided by such tools.

  2. Three tier architecture

    The same applies for Nginx instances as for two tier, although client tier ones solve to the business tier applications (using the internal cloud load balancer) plus the units contained locally. Business tier would behave similarly as client one in two tier architecture, but taking into account the proper configuration of security groups.

For both cases, the data tier forms an independent region (SkyDNS) or datacenter (Consul). Additionally, you could eventually skip Nginx, but you would need to open more ports in your security groups publicly.

Gathering knowledge from:

I was able to build:

TODO: Consul version. Although, there is the example for SkyDNS and Ambassadord.


** Let me please know your comments.


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