momy

library0.8.1jsnpmunverified

Momy is a command-line tool for replicating MongoDB collections to MySQL in real-time using MongoDB's Replica Set oplog. Version 0.8.1 is the latest stable release. It enables SQL queries on NoSQL data and access via Excel or Access. Key differentiators include support for field name normalization, dot-notation field mapping, and Docker deployment. It requires MongoDB Replica Set and MySQL setup, and uses a configuration file (momyfile.json) to define collections and field types.

database devops

npm install momy

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MOMY

momy

databasejavascriptv0.8.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

momy

✓ npx momy

✗ import momy from 'momy'

Momy is a CLI tool, not a library. Run via npx or global install.

configuration

✓ Create a momyfile.json

✗ Passing options via command line flags

Configuration is via a JSON file, not CLI flags except --config.

docker image

✓ docker run cognitom/momy

✗ using npm install -g inside docker

Official Docker image is available. Use volume mount for config.

Shows basic setup: create config, import existing data, then start streaming replication.

// 1. Create momyfile.json { "src": "mongodb://localhost:27017/mydb", "dist": "mysql://root:password@localhost:3306/mydb", "collections": { "users": { "_id": "string", "name": "string", "email": "string" } } } // 2. Import all data npx momy --config momyfile.json --import // 3. Start real-time replication npx momy --config momyfile.json

Debug

Known issues

gotchaMongoDB must be in Replica Set mode even if not replicating; rs.initiate() is required.

fix

Start mongod with --replSet rs0 --oplogSize 100, then run rs.initiate() in mongo shell.

affects: >=0.0.0

gotchaField name normalization with fieldCase changes _id to id, which may break existing queries.

fix

If using fieldCase, update any references to use 'id' instead of '_id'.

affects: >=0.0.0

deprecatedThe --import flag may not work as expected with large datasets; no batching or progress indication.

fix

Consider using mongodump/mongorestore for initial load if data is large.

affects: >=0.8.0

Errors

Common errors & fixes

Error: connect ECONNREFUSED 127.0.0.1:3306

MySQL server not running or incorrect host/port in momyfile.json.

fix

Ensure MySQL is running and the connection URL in momyfile.json is correct.

MongoError: not master and slaveOk=false

MongoDB not in Replica Set mode or not initialized.

fix

Start mongod with --replSet rs0 and run rs.initiate() in mongo shell.

Error: Cannot find module 'momy'

Attempting to import momy as a Node.js module instead of using CLI.

fix

Use npx momy or install globally with npm install -g momy.

Upgrade

Version history

0.8.1latest on npm

Audit

Dependencies

mongodbrequiredMongoDB Replica Set must be running and accessible

mysqlrequiredMySQL server must be running and accessible

Agent activity

9 hits · last 30 days

node

Resources

githubgit://github.com/cognitom/momy ↗

packagemomy ↗

homepagehttps://github.com/cognitom/momy#readme ↗