Mongodb-watcher NPM

Monitor your mongodb connection for bad queries in the client-side.

Installation

npm i mongodb-watcher

Usage

//connect to mongodb
const watcher = new MongoWatcher(db, {
  longCursorThreshold:  100,
  largeInsertThreshold: 1024 * 30,
  largeFetchThreshold:  1024 * 30
});

watcher.on('long.cursor.enumeration', (data) => {
  logger.error(`Detected bad query over ${data.collection} returning ${data.count} documents. \n ${data.stack}`);
});

db.collection('apples').find().toArray((apples) => {
  res.json(apples);
});

Events

`long.cursor.enumeration`

This event is emitted when a cursor is enumerated (.toArray) returning an array of documents with more than longCursorThreshold (defaults 100).

The data of the event contains:

collection: the name of the collection
count: the number of documents returned or inserted
stack: an stack trace of to identify where the call was made
cmd: it contains the query, limit, skip, readPreference, slaveOk, etc.

`large.document.insert`

This event is emitted when calling .insert([]) or .save with a document of size greater than bigInsertThreshold (defaults 30k).

collection: the name of the collection
documentId: the document._id value
size: the size of the doc in bytes
cmd: it contains the query, limit, skip, readPreference, slaveOk, etc
stack: an stack trace of to identify where the call was made