Overview

High Availability¶

In the intricate landscape of blockchain infrastructure, high availability is not merely an added benefit but a fundamental necessity. Our architecture is inherently resilient, a quality we owe to a modular approach underpinned by Kubernetes. This orchestration platform not only simplifies the deployment of multiple replicas but also ensures the seamless rescheduling of workloads, effectively minimizing the risk of service interruptions. However, it's imperative to note that stateful workloads demand a unique set of considerations. Specifically, the meticulous configuration of our chosen storage solution, Ceph, is indispensable for sustaining a highly available cluster.

The ambition for our home-based lab is both straightforward and lofty: the system should be capable of enduring the loss of a single node with minimal to no disruption. On the networking front, we've architected redundancy at the hardware layer, achieved through dual NICs on each node and redundant switches and routers. Yet, the challenge of ISP-level redundancy persists. As we've previously discussed in the Networking section, securing dual ISP connections for true network resilience is often a hurdle for independent operators.

To fortify against power-related contingencies, our entire setup, from compute to network, is backed by a battery backup system. While this mitigates hardware damage and eliminates the need for a full system reboot, it's unlikely to preserve internet connectivity during a broader power outage, given the grid dependency of intermediate ISP equipment. By adhering to these guidelines and leveraging the insights gained from establishing the primary home infrastructure, we aim to institutionalize high availability, making it an integral part of our operational ethos.

Disaster Recovery¶

As independent operators running blockchain nodes from home, we're inherently exposed to a set of unique risks. To mitigate these, a robust off-site disaster recovery (DR) strategy is essential. One of the primary challenges we face is cost-efficiency, particularly when leveraging cloud resources for DR. Our approach is to maintain a minimal cloud footprint, scaling up only in the event of an actual disaster. However, continuous data replication is a non-negotiable aspect, given its role in averting the need for time-consuming blockchain data syncs during crises. This, in turn, constitutes the bulk of the DR operational cost.

The complexity tied to failover operations presents another challenge, but it's one that can be overcome with careful planning and precise execution. This guide is designed to equip home operators with the necessary insights and confidence to navigate disaster scenarios effectively. While it's impossible to anticipate every unique setup or failure condition, we will offer DR failover playbooks and templates that address a broad range of typical scenarios.

Embarking on the DR planning phase represents the final, yet pivotal, stage in our journey as independent home operators. The expertise acquired from establishing a stable primary home infrastructure will instill the confidence needed to implement and execute a resilient DR strategy.