What methods ensure the reliability and continuity of the system in case of failures?

The following methods are used to ensure system reliability and continuity during failures:

• Redundancy and fault tolerance: using clusters, data replication, automatic switch-over to backup nodes.
• Monitoring and alerting: constant system status monitoring and prompt notification of issues.
• Transactions and rollback: applying atomic operations and rollback mechanisms to maintain data integrity.
• Error handling and retries: implementing logic for repeated requests or operations during temporary failures.
• Backup (backup copies): regularly creating data copies for recovery after critical errors.
• Use of design patterns: for example, Circuit Breaker to prevent cascading failures.

Example in Python with retry on temporary error:

import time

def reliable_request():
    for attempt in range(3):
        try:
            # call external service
            result = external_service_call()
            return result
        except TemporaryError:
            time.sleep(2 ** attempt)  # exponential backoff
    raise Exception("Service unavailable after multiple attempts")