[Summer 2021] Support SAGA mode

[dk-lockdown]

Background

The SAGA mode is driven by a state machine. In the Saga mode, each participant in the business process submits a local transaction. When a participant fails, it will compensate the previously successful participant. The first-stage forward service and the second-stage compensation service All are implemented by business developer. The Seata Java version already supports SAGA mode.

Target

make seata-golang support saga mode.

Difficulty

High

Mentor

@dk-lockdown

Output Requirements

Support describing state machine with state diagram.
Distributed transactions driven by the state machine to achieve final consistency.

Technical Requirements

Familiar with the Seata-Golang，and, understand the principle of SAGA mode.

背景

SAGA 模式由状态机驱动，在Saga模式中，业务流程中每个参与者都提交本地事务，当出现某一个参与者失败则补偿前面已经成功的参与者，一阶段正向服务和二阶段补偿服务都由业务开发实现。Seata Java 版本已经支持 SAGA 模式。

目标

使 Seata-Golang 支持 SAGA 模式。

难度

高

导师

@dk-lockdown

产出要求

支持用状态图描述状态机
由状态机驱动分布式事务达到最终一致性

能力要求

熟悉 Seata-Golang 框架，了解 SAGA 模式的原理。