Sequencer Failover Test Tool

WHAT IT DOES

This tool tests sequencer failover readiness by analyzing primary and backup sequencer status, heartbeat data, and failover event history. It provides a comprehensive assessment of whether a backup sequencer is ready to take over if the primary sequencer fails. The tool checks primary and backup contract verification, status indicators, heartbeat recency, block production activity, and historical failover events. Results are presented as a detailed failover readiness report with status indicators (ready/standby/failed), failover readiness flags, and an overall readiness score. This is essential for L2 operators ensuring high availability, developers testing failover mechanisms, and stakeholders verifying sequencer resilience.

HOW TO USE

Connect your wallet (read-only, no transaction required) and select the target network. Enter the failover system name, primary sequencer address, backup sequencer address, and set the lookback blocks for failover analysis. Click "test failover readiness" and the tool will verify both contracts, analyze their status and heartbeat data, and generate a comprehensive failover report. Results display a summary with failover readiness percentage, detailed failover cards showing each sequencer's status, block production, last activity, and failover readiness, and a table of all sequencers with their statuses. Use the report to identify failover gaps, ensure backup sequencers are ready, and maintain high availability for your sequencer infrastructure.

TECHNICAL MECHANISM

The analyzer uses ethers.js v5.7.2 to perform a multi-stage failover readiness test. First, it calls eth_getCode to verify both primary and backup sequencer contracts are deployed and uses block explorer APIs to fetch verification status and source code. The tool then scans historical logs using eth_getLogs across the specified block range to identify failover events (e.g., FailoverTriggered, FailoverComplete, SequencerStatusChanged), heartbeat events, and block production data. It queries the contract state via eth_call to retrieve current status information, registration data, and last heartbeat timestamps for both primary and backup sequencers. The tool analyzes each sequencer's status: primary sequencer (checking if it's active and producing blocks), backup sequencer (checking if it's in standby mode and ready for failover), and any additional backups. It calculates failover readiness based on multiple factors: contract verification status, heartbeat recency, block production consistency, and historical failover success rates. Each sequencer is assigned a status: ready (fully operational and ready for failover), standby (available but not actively producing), or failed (not ready for failover). Results are compiled into a structured report with detailed sequencer information, status indicators, and an overall readiness score.

WHAT IT CANNOT SEE

This tool cannot actually trigger failover or test backup sequencer performance—it performs analysis and verification only. It is limited by the RPC provider's rate limits and block range availability for historical log queries. It cannot simulate failover scenarios or network conditions such as latency, throughput, or state synchronization delays. The analysis relies on the accuracy and completeness of contract verification and failover event data; incomplete logs or unverified contracts may produce incomplete results. It cannot analyze contracts that are not verified or have opaque failover mechanisms where status events are not emitted. The tool is limited to the specific sequencer contracts and failover events that are accessible via RPC. It cannot guarantee that failover readiness reflects actual backup performance without manual review and actual failover testing—the tool provides an on-chain view, but actual failover performance may differ due to off-chain factors.

PLEASE NOTE

This is a read‑only analytics tool—it never submits transactions or triggers failover. It is designed for EVM‑compatible chains with sequencer contracts that emit status and failover events. The failover test results are for informational and audit purposes only and should not be considered a guarantee of failover success. Always validate failover mechanisms through regular drills and actual failover testing in a staging environment. The tool's status indicators are heuristic and based on the selected lookback period and observed patterns—customize thresholds based on your specific requirements and expected sequencer behavior.