Distributed Transaction

A distributed transaction is a single logical transaction that spans multiple physical servers or nodes.

The physical separation of these nodes makes it challenging to ensure that distributed transactions fully satisfy the ACID properties (atomicity, consistency, isolation, and durability). Satisfying these properties requires close coordination among the participating servers.

In some scenarios, systems deliberately relax strict ACID compliance to gain other benefits, such as higher availability or looser coupling between services.

There are two primary approaches to consistency in distributed transactions:

• Strong Consistency: Systems aiming for strong consistency require that a transaction is atomically committed across all relevant nodes. This means that all parts of the transaction either succeed or fail as a single, indivisible unit.

  This model typically uses strict algorithms, often involving locking mechanisms, to ensure the isolation property and prevent transactions from interfering with one another.

• Eventual Consistency: In this model, transactions are often divided into phases that may be committed at different times across nodes.

  Because of this asynchronous behavior, the system must be designed to implicitly avoid or resolve inconsistencies over time, eventually reaching a consistent state across all nodes.