Node Failure

Overview

Node failure covers more than a crashed process. A node can remain online while serving stale blocks, rejecting valid transactions, or failing to participate in consensus. The impact depends on its role: failure of one RPC node affects application access, while failure of enough validators can delay finality or halt block production. Redundant nonvalidator nodes may fail with little network-wide effect.

Common causes include software defects, resource exhaustion, disk corruption, networking loss, incompatible upgrades, bad configuration, and compromised credentials. Monitoring should correlate process status with Node Health, peer connectivity, synchronization lag, database integrity, and role-specific duties. A single green health endpoint is not sufficient to rule out failure.

Applications must decide whether to fail over, degrade, or stop. Read-only queries may switch to another independently operated node, but settlement-critical actions should not combine inconsistent chain views without reconciliation. Validators need special controls to avoid double signing when a replacement instance starts. Key custody and slashing protection data must remain consistent during recovery.

Post-failure analysis should preserve logs, metrics, software versions, chain head, peer information, and storage evidence. A tested Node Recovery runbook should define when to restart, rebuild, restore a snapshot, rotate credentials, or replace hardware. The objective is not just rapid uptime but verified return to the correct canonical and finalized state.

When applying Node Failure, teams should separate directly observed protocol facts from interpretation. any loss of required correctness or service, including stale or unsafe operation even when the process is still running. For Node Failure, keeping the underlying identifiers and validation context makes incident review, reconciliation, and future migrations more reliable.