mongo-oplog

Watch mongodb oplog in a simple way

mongo-oplog

Listening to MongoDB live changes using oplog.

$ npm install mongo-oplog

Check the upgrading guide here

Go here for the old 0.x readme

var MongoOplog = require('mongo-oplog');
var oplog = MongoOplog('mongodb://127.0.0.1:27017/local', { ns: 'test.posts' }).tail();
 
oplog.on('op', function (data) {
  console.log(data);
});
 
oplog.on('insert', function (doc) {
  console.log(doc.op);
});
 
oplog.on('update', function (doc) {
  console.log(doc.op);
});
 
oplog.on('delete', function (doc) {
  console.log(doc.op._id);
});
 
oplog.on('error', function (error) {
  console.log(error);
});
 
oplog.on('end', function () {
  console.log('Stream ended');
});
 
oplog.stop(function () {
  console.log('server stopped');
});
  • uri: Valid MongoDB uri or a MongoDB server instance.
  • options MongoDB onnection options.

Start tailing.

oplog.tail(function(){
  console.log('tailing started');
})

Stop tailing and disconnect from server.

oplog.stop(function() {
  console.log('tailing stopped');
});

Destroy the mongo-oplog object by stop tailing and disconnecting from server.

oplog.destroy(function(){
  console.log('destroyed');
})

Pause and resume oplog events.

oplog.ignore = true; // to pause 
oplog.ignore = false // to resume 

Create and return a filter object.

var filter = oplog.filter('*.posts');
filter.on('op', fn);
oplog.tail();

Destroy filter object.

filter.destroy(function(){
  console.log('destroyed');
})

Pause and resume filter events.

filter.ignore = true; // to pause 
filter.ignore = false // to resume 

Events supported by oplog and filter;

  • op: All bellow operations (oplog/filter).
  • insert: Document insert (oplog/filter).
  • update: Document update (oplog/filter).
  • delete: Document delete (oplog/filter).
  • end: Cursor stream ended (oplog).
  • error: Error (oplog).

Configure MongoDB for ac active oplog:

Start MongoDB with:

$ mongod --replSet test

Start a mongo shell and configure mongo as follows:

> var config = {_id: "test", members: [{_id: 0, host: "127.0.0.1:27017"}]}
> rs.initiate(config)

Once configuration is initiated then you can run the test:

$ npm install
$ make test

(The MIT License)

Copyright (c) 2015 Jonathan Brumley <cayasso@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.