README.md

rethinkdb-changefeed-reconnect

Simple helper module for having RethinkDB changefeed listeners automatically reconnect if they lose their connection (i.e., if the database server goes down or restarts).

Right now, there is a single (default) function exported: processChangeFeedWithAutoReconnect.

Getting Started

1. Install the module in your project

    $ npm install --save rethinkdb-changefeed-reconnect
   

How to Use

Basically, you need to implement 3 functions and configure your options:

1. getFeed(): this should return a RethinkDB .changes() query Promise
2. onFeedItem(item): this is the function that processes each new data item
3. onError(err): this function is where errors will be sent

The available options are:

• changefeedName: used for logging purposes so you can differentiate your different feeds
• attemptDelay: how long (in milliseconds) to wait between reconnect attempts
• maxAttempts: how many reconnect attempts to try before giving up
• silent: whether or not you want the logger to be silenced (default = false)
• logger: must be an object with 4 functions: log, info, warn, and error (default = global.console)

Example

import rethinkdbdash from 'rethinkdbdash'
import processChangefeed from 'rethinkdb-changefeed-reconnect'

const r = rethinkdbdash({servers: {host: 'localhost', port: 28015, db: 'todo'}, silent: true})

processChangefeed(newTasksFeed, handleNewTask, handleError, {
  changefeedName: 'my changefeed',
  attemptDelay: 3000,
  maxAttempts: 3,
  silent: false,
  logger: global.console,
})

function newTasksFeed() {
  r.table('tasks')
    .changes()
    .filter(r.row('old_val').eq(null))
}

function handleNewTask(task) {
  console.log({task})
}

function handleError(err) {
  console.error(err.stack)
}

See also the provided example.

You can run it like so: node example

Then, after you run it, stop your RethinkDB server and watch what gets logged (assuming you passed silent: false in your options).

Notes

This module was developed on top of rethinkdbdash.

Contributing

Read the instructions for contributing.

1. Clone the repository.

2. Run the setup tasks:

    $ npm install
    $ npm test
   

License

See the LICENSE file.