mysql57

go-workflows MySQL 5.7 backend

This package provides a MySQL 5.7-compatible backend for github.com/cschleiden/go-workflows.

It is a small fork of the upstream backend/mysql package. The upstream backend uses FOR UPDATE ... SKIP LOCKED, which is available in MySQL 8+ but not in MySQL 5.7. This fork replaces workflow and activity task pickup with optimistic lock claims:

1. Select a small batch of candidate task ids.
2. Claim one row with a conditional UPDATE on the queue, lease state, worker, and per-lease lock_token.
3. Read task details only if the current worker won the claim.

Leases are completed or extended only when the worker name, lock token, workflow or activity identity, and non-expired lease all match. Lease expiry and renewal use MySQL's CURRENT_TIMESTAMP(6). Connections pin the MySQL session time zone to UTC so database-side lease timestamps and Go time.Time values share the same baseline. The schema uses DATETIME(6) plus claim indexes for MySQL 5.7.

Install

go get github.com/DnullP/go-workflows-mysql57

Usage

import mysql57 "github.com/DnullP/go-workflows-mysql57"

backend := mysql57.NewMysqlBackend(
    "127.0.0.1",
    3306,
    "root",
    "root",
    "workflow_demo_mysql57",
    mysql57.WithTaskClaimBatchSize(32),
)

WithTaskClaimBatchSize controls how many candidate rows are inspected during optimistic task pickup. The default is 16.

Status

This package is intended for MySQL 5.7 compatibility with go-workflows v1.4.1. It is covered by the upstream backend contract tests plus MySQL 5.7 integration tests for concurrent claims, delayed activity visibility, expired leases, stale lease reclaim, UTC session time, and deleted/completed lease handling.

License

MIT. This fork includes code derived from github.com/cschleiden/go-workflows, which is also MIT licensed.