Heuristic exceptions in the context of software architecture refer to a situation where a transaction participant decides to unilaterally commit or rollback changes without consensus, typically due to a communication failure or other catastrophic issues in a distributed system. This decision is known as a heuristic decision.
In distributed transaction systems, where multiple participants work together to complete a transaction, each participant usually communicates with a transaction manager to ensure all parts of the transaction are committed or rolled back together. This maintains the atomicity of the transaction. However, if a participant cannot communicate with the transaction manager for an extended period, it may independently decide to commit or rollback its part of the transaction. This independent action is what is termed as a heuristic exception.
Heuristic exceptions are considered severe errors in transaction systems because they can lead to inconsistencies where some parts of the transaction are committed while others are rolled back, violating the atomicity and integrity of the transaction. This can potentially lead to data corruption or loss.
To manage the risks associated with heuristic exceptions, systems are designed to log all h...
