Fault Recovery

Overview

A fault may affect a signer, node, database, network connection, device, API, queue, or policy engine. Recovery can involve failover, restart, replacement, replay, state reconstruction, or degraded operation. The fault itself is a cause, while the visible service failure is its effect.

Redundancy does not guarantee safe recovery. Two components may share the same dependency, corrupted state, credential, or configuration. In signing systems, uncontrolled failover can create conflicting actions or double signing. In payment systems, replaying queued work can duplicate transfers unless operations are idempotent.

Architectures should define health signals, fault domains, authoritative state, safe failover rules, and consistency checks. Recovery tests should include partial and correlated failures. After restoration, teams should verify balances, pending actions, key state, and audit logs rather than relying only on service availability.

For Fault Recovery, important risks include fraudulent recovery requests, guardian collusion, unavailable shares, outdated backups, compromised cloud accounts, missing derivation metadata, untested procedures, and simultaneous loss of primary and backup systems. For Fault Recovery, independent storage and periodic exercises reduce correlated failure but introduce their own custody obligations.

Evidence for Fault Recovery should preserve incident time, affected identifiers, last known state, claimant and approver checks, backup or share version, actions performed, credentials revoked, assets verified, discrepancies found, and final owner acceptance. For Fault Recovery, sensitive recovery material must not appear in the incident record.

Fault Recovery differs from ordinary retry or customer support because it restores authority after a control failure. For example, reinstalling an application is not successful recovery until the correct accounts, networks, balances, policies, and transaction history are reproduced and compromised authority can no longer act.