How do you troubleshoot Disaster recovery when it fails?

When disaster recovery fails, it can be a critical situation that requires immediate troubleshooting. Here are some steps you can take to effectively identify and solve the issues causing the failure:

1. Assess the Situation

Start by understanding the extent of the failure. Determine if it is a complete loss of service or if certain functionalities are still operational.

2. Gather Logs and Metrics

Collect logs from the affected servers and applications. Logs can provide insights into what went wrong and can help identify the root cause of the failure.

3. Validate Infrastructure

Check the health of the infrastructure, including servers, storage, and network components. Ensure that all resources are operational and that there are no hardware failures.

4. Verify Configuration

Review the configuration files for both the primary and backup systems. Ensure that all settings are correct and that nothing has been misconfigured during the failover process.

5. Test Recovery Procedures

If possible, conduct tests to verify that your disaster recovery procedures are working correctly. This will also help you identify any gaps in the process.

6. Update Documentation

After resolving the issues, update your disaster recovery documentation to reflect any changes made during the troubleshooting process.

Example Code Snippet

    // Example of logging error during recovery attempt
    function logError($error) {
        $logFile = '/var/log/dr_failures.log';
        file_put_contents($logFile, date('Y-m-d H:i:s'). " - Error: " . $error . PHP_EOL, FILE_APPEND);
    }

    try {
        // Attempt to restore service
        restoreService();
    } catch (Exception $e) {
        logError($e->getMessage());
    }