The Myth of the Single Cloud: Resilience and Sovereignty in 2016

If you are running your entire stack on a single availability zone in AWS us-east-1, you aren't an engineer; you're a gambler. In 2016, the narrative has shifted. It is no longer about if a cloud provider will fail, but when. For CTOs and Systems Architects operating out of Oslo or Stavanger, the challenge is twofold: maintaining 100% uptime during outages and navigating the murky waters of the newly adopted EU-US Privacy Shield.

Multi-cloud isn't just a buzzword to impress the board. It is an insurance policy. However, it introduces complexity that can cripple a team if managed poorly. This guide strips away the marketing fluff and focuses on the technical execution of a hybrid strategy using Terraform, Ansible, and strategic geographic placement.

The Latency vs. Compliance Trade-off

Here is the reality check: Light has a speed limit. If your users are in Norway, but your servers are in Frankfurt (AWS) or Ireland, you are fighting physics. You are adding 20-40ms of round-trip time (RTT) on every packet. For a dynamic Magento store or a high-frequency trading app, that latency compounds.

Furthermore, with the Safe Harbor framework invalidated last year and the Privacy Shield only just adopted in July 2016, data sovereignty is a legal minefield. Keeping your core database on Norwegian soil—protected by the Datatilsynet guidelines—while bursting compute to the public cloud is not just performant; it is legally prudent.

Pro Tip: Do not blindly trust "availability zones" to save you. We have seen entire regions suffer control plane failures. True redundancy means different providers, different distinct physical networks, and different billing accounts.

Infrastructure as Code: The Terraform 0.7 Approach

Manual configuration is dead. If you are logging into a portal to click "Create Droplet" or "Launch Instance," you have already failed scalability. To manage CoolVDS instances alongside AWS EC2 resources, we utilize HashiCorp's Terraform (currently v0.7). It allows us to describe our infrastructure declaratively.

Below is a pragmatic example of how we define a failover structure. We keep the stateful "Performance Core" on CoolVDS (for raw NVMe IOPS) and the stateless application logic on a scalable cloud tier.

Defining the Provider Agnostic Structure

Using Terraform, we can provision resources across different providers in a single main.tf file. This abstraction is critical for rapid disaster recovery.

# Configure the CoolVDS Provider (Generic OpenStack/KVM Interface)
provider "openstack" {
  user_name   = "admin"
  tenant_name = "admin"
  password    = "${var.openstack_password}"
  auth_url    = "https://auth.coolvds.com:5000/v2.0"
}

# Configure AWS Provider
provider "aws" {
  region = "eu-central-1"
}

# Resource: CoolVDS NVMe Instance (Primary DB)
resource "openstack_compute_instance_v2" "db_primary" {
  name            = "db-master-oslo"
  image_name      = "Ubuntu 16.04"
  flavor_name     = "vds.nvme.large"
  key_pair        = "deployer-key"
  security_groups = ["default"]

  network {
    name = "public-net"
  }
}

# Resource: AWS EC2 Instance (Stateless App Server)
resource "aws_instance" "app_node" {
  ami           = "ami-af0fc0c0"
  instance_type = "t2.medium"

  tags {
    Name = "app-worker-frankfurt"
  }
}

This configuration allows you to version control your infrastructure. If the Frankfurt region degrades, you can spin up app nodes in CoolVDS's Oslo datacenter by simply changing the resource target and running terraform apply.

The Database Dilemma: Replication Across Networks

Compute is easy; data is gravity. Synchronous replication between Oslo and Frankfurt is impossible due to latency. The transaction lock wait time would kill your throughput. The solution is Asynchronous Master-Slave Replication.

We recommend hosting the Master database on CoolVDS. Why? Because NVMe storage is standard here. On public clouds, you often pay a premium for "Provisioned IOPS." By keeping the write-heavy master on dedicated resources, you avoid the "noisy neighbor" effect common in shared public cloud hypervisors.

MySQL 5.7 Configuration for WAN Replication

To set this up securely over the public internet, you must use SSL and specific binary log settings. Here is the requisite my.cnf configuration for the master node:

[mysqld]
# Unique ID for the Master
server-id = 1

# Binary Logging is required for replication
log_bin = /var/log/mysql/mysql-bin.log
binlog_format = ROW

# Safety: Ensure data durability
innodb_flush_log_at_trx_commit = 1
sync_binlog = 1

# Network Optimization for WAN
max_allowed_packet = 64M
slave_net_timeout = 60

# Security: Bind to private interface or VPN IP
bind-address = 0.0.0.0

For the connection between your cloud providers, do not use the public internet directly. Setup an IPsec VPN (using StrongSwan or OpenVPN) or use an SSH tunnel. Exposing port 3306 to the world is negligence.

Cost Comparison: TCO Analysis

Many startups burn cash by over-provisioning in the public cloud. Let's look at the numbers for a standard 4 vCPU, 16GB RAM setup with high-speed storage.

The "Split-Brain" Risk and DNS

When running multi-cloud, DNS is your traffic cop. We utilize Geo-DNS. Users in Scandinavia are routed to the CoolVDS IP in Oslo. Users in Central Europe hit the AWS IP in Frankfurt.

However, you need a health check. If the Norway uplink fails, DNS must update with a low TTL (Time To Live). Set your TTL to 60 seconds.

# Example Bind9 Zone Snippet
$TTL    60
@       IN      SOA     ns1.coolvds.com. admin.coolvds.com. (
                        2016092801      ; Serial
                        604800          ; Refresh
                        86400           ; Retry
                        2419200         ; Expire
                        60 )            ; Negative Cache TTL
;

Conclusion: Control Your Infrastructure

The cloud is a tool, not a religion. In 2016, the smartest architecture is one that balances the elasticity of the mega-clouds with the performance, cost-efficiency, and data sovereignty of local providers like CoolVDS. By using Terraform to abstract the differences and keeping your data gravity local, you build a system that is robust against outages and compliant with European privacy standards.

Don't let latency kill your conversion rates. Deploy a test NVMe instance on CoolVDS today and benchmark the I/O against your current provider. The results will speak for themselves.