soundcloud/lhm
Online MySQL schema migrations observed · 2026-08-28
Health v2 · maintenance only
10/100
- Activity 91
- Release rhythm 35
- Longevity 100
Flags: no_releases archived
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.
- gap_med: n/a
- age_days: 5600
- days_rel: n/a
- days_push: 55
- n_releases_24m: 0
Adoption not part of the score
1852 stars · 193 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
Large Hadron Migrator (LHM) is a Ruby gem for performing online MySQL schema migrations without locking large tables. It works alongside ActiveRecord migrations by copying data into a new table with triggers keeping it in sync while the system stays live.
Use cases
- run ALTER TABLE on a table with millions of rows without downtime
- add or change indexes on large MySQL tables while the site is live
- evolve a Rails database schema without long table locks
- perform online column additions on busy MySQL tables
- migrate large ActiveRecord-backed tables safely in production
When to choose
- you have a legacy Rails app on MySQL with very large tables and no other online migration tooling
- you need trigger-based online schema changes with a simple integer id primary key
- you want a lightweight gem instead of running external percona/gh-ost tooling
When to avoid
- you are starting a new project - the repository is no longer actively maintained and is archived
- you use PostgreSQL or a database other than MySQL
- your tables lack a single auto-increment integer id column or have sparse ids
- you need support for modern Ruby or ActiveRecord versions
Facets
library · maturity abandoned
database orm databases developer-tools web-development ruby mysql schema-migration activerecord online-migration zero-downtime archived
1 source
- readme: https://github.com/soundcloud/lhm · fetched 2026-08-28 · 185f7f8ef8bf
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| soundcloud/lhm | main | 10 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem