rethinkdb-changefeed-reconnect

0.3.2 • Public • Published

rethinkdb-changefeed-reconnect

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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.

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Install

npm i rethinkdb-changefeed-reconnect

Weekly Downloads

716

Version

0.3.2

License

ISC

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Collaborators

  • mxstbr
  • jeffreywescott