mirror of
https://github.com/tiennm99/java-design-patterns.git
synced 2026-05-16 22:59:11 +00:00
Ilkka Seppälä
4108f86177
* Changed database implementation. Removed static objects. * Fix Logs * Fix 40 errors from checkstyle plugin run. 139 left)) * Fix CacheStore errors from checkstyle plugin 107 left * Fix last errors in checkstyle. * Fix sonar issues * Fix issues in VALIDATE phase * Fix Bug with mongo connection. Used "Try with resources" * Add test * Added docker-compose for mongo db. MongoDb db work fixed. * Provided missing tests * Comments to start Application with mongo. * Fix some broken links * Remove extra space * Update filename * Fix some links in localization folders * Fix link * Update frontmatters * Work on patterns index page * Work on index page * Fixes according PR comments. Mainly Readme edits. * fix frontmatter * add missing png * Update pattern index.md * Add index.md for Chinese translation * update image paths * update circuit breaker image paths * Update image paths for localizations * add generated puml * Add missing image * Update img file extensions * Update the rest of the EN and ZH patterns to conform with the new website Co-authored-by: Victor Zalevskii <zvictormail@gmail.com>
48 lines
1.8 KiB
Markdown
48 lines
1.8 KiB
Markdown
---
|
|
title: Saga
|
|
category: Concurrency
|
|
language: en
|
|
tags:
|
|
- Cloud distributed
|
|
---
|
|
|
|
## Also known as
|
|
This pattern has a similar goal with two-phase commit (XA transaction)
|
|
|
|
## Intent
|
|
This pattern is used in distributed services to perform a group of operations atomically.
|
|
This is an analog of transaction in a database but in terms of microservices architecture this is executed
|
|
in a distributed environment
|
|
|
|
## Explanation
|
|
A saga is a sequence of local transactions in a certain context. If one transaction fails for some reason,
|
|
the saga executes compensating transactions(rollbacks) to undo the impact of the preceding transactions.
|
|
There are two types of Saga:
|
|
|
|
- Choreography-Based Saga.
|
|
In this approach, there is no central orchestrator.
|
|
Each service participating in the Saga performs their transaction and publish events.
|
|
The other services act upon those events and perform their transactions.
|
|
Also, they may or not publish other events based on the situation.
|
|
|
|
- Orchestration-Based Saga
|
|
In this approach, there is a Saga orchestrator that manages all the transactions and directs
|
|
the participant services to execute local transactions based on events.
|
|
This orchestrator can also be though of as a Saga Manager.
|
|
|
|
## Class diagram
|
|
|
|
|
|
## Applicability
|
|
Use the Saga pattern, if:
|
|
|
|
- you need to perform a group of operations related to different microservices atomically
|
|
- you need to rollback changes in different places in case of failure one of the operation
|
|
- you need to take care of data consistency in different places including different databases
|
|
- you can not use 2PC(two phase commit)
|
|
|
|
## Credits
|
|
|
|
- [Pattern: Saga](https://microservices.io/patterns/data/saga.html)
|
|
- [Saga distributed transactions pattern](https://docs.microsoft.com/en-us/azure/architecture/reference-architectures/saga/saga)
|