# DTM — Distributed Transaction Manager for Microservices

> A cross-language distributed transaction framework supporting Saga, TCC, XA, and two-phase message patterns for reliable microservice coordination.

## Install

Save in your project root:

# DTM — Distributed Transaction Manager for Microservices

## Quick Use
```bash
# Run the DTM server
docker run -d -p 36789:36789 yedf/dtm

# Register a Saga transaction (Go example)
saga := dtmcli.NewSaga(dtmServer, dtmcli.MustGenGid(dtmServer)).
    Add(busiServer+"/TransOut", busiServer+"/TransOutCompensate", req).
    Add(busiServer+"/TransIn", busiServer+"/TransInCompensate", req)
err := saga.Submit()
```

## Introduction
DTM is an open-source distributed transaction framework that coordinates multi-service operations reliably. It implements industry-standard patterns including Saga, TCC, XA, and two-phase messaging, providing a language-agnostic HTTP/gRPC API so any microservice can participate in a global transaction regardless of its tech stack.

## What DTM Does
- Orchestrates distributed transactions across multiple microservices and databases
- Implements Saga, TCC (Try-Confirm-Cancel), XA, and outbox patterns
- Provides an HTTP and gRPC API accessible from any programming language
- Retries failed branches automatically with configurable backoff and timeout
- Guarantees eventual consistency even when services or networks fail temporarily

## Architecture Overview
DTM runs as a standalone server that stores transaction state in MySQL, Postgres, or Redis. Client SDKs register transaction branches (sub-operations) with the server. The server drives the protocol: for Saga it calls each step in sequence and triggers compensations on failure; for TCC it coordinates try, confirm, and cancel phases. A built-in cron job retries incomplete transactions.

## Self-Hosting & Configuration
- Deploy the DTM server via Docker, binary, or Kubernetes Helm chart
- Configure the backend store (MySQL, Postgres, or Redis) via environment variables
- Client SDKs are available for Go, Java, Python, C#, PHP, and Node.js
- Set retry intervals, timeout durations, and concurrency limits per transaction type
- Enable the admin dashboard for monitoring in-flight and failed transactions

## Key Features
- Language-agnostic HTTP/gRPC interface works with any tech stack
- Sub-transaction barriers prevent duplicate execution on retries
- Supports mixing different patterns (e.g., Saga + TCC) in one global transaction
- Admin API and dashboard for observing transaction status in real time
- Lightweight server with minimal resource requirements

## Comparison with Similar Tools
- **Seata** — Java-centric; DTM is language-agnostic via HTTP/gRPC
- **Temporal** — workflow engine for general orchestration; DTM is specialized for transaction patterns
- **Eventuate Tram** — event-driven Saga framework for Java/Spring; DTM supports multiple patterns and languages
- **Cadence** — general-purpose workflow by Uber; DTM focuses on transaction consistency with simpler setup

## FAQ
**Q: Which transaction pattern should I choose?**
A: Saga is simplest for most cases. Use TCC when you need reservation semantics, and XA when your databases support two-phase commit natively.

**Q: Does DTM support exactly-once execution?**
A: DTM provides at-least-once delivery with sub-transaction barriers that prevent duplicate side effects, achieving effectively-once semantics.

**Q: What happens if the DTM server crashes?**
A: Transaction state is persisted in the backend store. On restart, DTM resumes incomplete transactions automatically.

**Q: Can DTM work with message queues?**
A: Yes. The two-phase message pattern integrates with any message queue to ensure messages are sent only when the local transaction commits.

## Sources
- https://github.com/dtm-labs/dtm
- https://en.dtm.pub

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Source: https://tokrepo.com/en/workflows/7cf55505-429a-11f1-9bc6-00163e2b0d79
Author: AI Open Source