What is Failure Masking?

Failure masking refers to the process of hiding the failure from the end-users or other parts of the system. The system continues to operate correctly despite the presence of failures. This is achieved by using redundancy and replication, ensuring that even if some components fail, others can take over seamlessly without affecting the system’s overall functionality.

• Purpose:
  • The primary objective of failure masking is to shield end-users or other parts of the system from being directly affected by failures.
  • This is particularly crucial in systems where uninterrupted operation is critical, such as in financial transactions, healthcare services, or critical infrastructure.
• Techniques:
  • Redundancy: This involves duplicating critical components or systems within the infrastructure so that if one fails, the redundant component can seamlessly take over. Redundancy can be implemented at various levels, including hardware, software, and data.
  • Replication: Similar to redundancy, replication involves creating multiple copies of critical data or processes across different locations or servers. If one copy fails, the system can switch to another without interruption.
  • Load Balancing: Distributing the workload across multiple servers or resources to prevent any single point from being overwhelmed by traffic or failing.
• Example: In a web server environment, if one server encounters a hardware failure, a load balancer can automatically redirect traffic to other available servers without users noticing any disruption.

In distributed systems, dealing with failures is a critical aspect of design and implementation. Since these systems consist of multiple interconnected components, the likelihood of failures increases. Two primary approaches to handling these failures are masking and tolerating them. This article explores the differences between these approaches, their techniques, and their use cases.