loadbalancing

README

Load balancing utilities

Utilities for load balancing of scale out storage solutions, such as the knsfd NFS proxy.

vip_manager

VIP Manager is a utility to manage virtual ("alias") IPs for instances in a Managed Instance Group. Virtual IPs are distributed in an even way between all the nodes in the instance group. When the number of nodes changes, Virtual IPs are automatically re-balanced.

Build

go build vip_manager.go

Run

vip_manager \
  -project PROJECT \
  -zone GCE_ZONE \
  -gce_instance_group INSTANCE_GROUP_NAME \
  -alias_network NAME_OF_ALIAS_NETWORK \
  -vips NETWORK_PREFIX

Replace works in ALL_CAPS with values for your environment.

Project and GCE zone are auto configured inside Google Cloud Platform (GCE or GKE).

Permissions

vip_manager needs permissions to:

1. List GCE instances and instance groups.
2. Add and remove alias IPs to/from GCE instances.

These permissions are not included in "Compute Engine Read Write" nor "Allow full access to all Cloud APIs" when creating a VM. One way to allow vip_manager to run inside a VM in GCE/GKE is to grant the "Compute Instance Admin (v1)" role to the GCE service account (PROJECT_NUMBER@project.gserviceaccount.com).

(TODO: Figure out a better way)

metrics_exporter

Metrics Exporter is a utility to export system metrics for load balancing, for example to load balance connections based on current NFS connections.

Build

go build metrics_exporter.go

Run

metrics_exporter [-p PORT]

The default port is 9001.

Manual test

curl http://IP:PORT/metrics

Replace IP and PORT.

Load balancing with Cloud DNS

Once vip_manager is set up and managing the virtual IPs, a simple way to orchestrate random ("round robin") DNS is using Google Cloud DNS.

Create a new private zone

Click "Create" then "Add Standard"

Add all the IPs in the virtual IP network prefix.

Example with the 10.9.8.0/30 prefix:

Virtual machines in the designated network can now query the new DNS zone.

# host myservice.loadbalancing.mydomain.com
myservice.loadbalancing.mydomain.com has address 10.9.8.3
myservice.loadbalancing.mydomain.com has address 10.9.8.1
myservice.loadbalancing.mydomain.com has address 10.9.8.0
myservice.loadbalancing.mydomain.com has address 10.9.8.2