Opbeat is joining forces with Elastic – Read our blog post

Get started with a custom Node.js stack

Getting Opbeat set up for your Node.js app is easy, and there are various ways you can tweak it to fit to your needs.

If you are using either Express, hapi or Koa, we recommend that you read these articles instead:

For a custom Node.js app, follow the guide below and refer to the API documentation for all the advanced stuff.

  Video:
Watch a short screencast about how to get started with Opbeat in your Node.js app.

Installation

$ npm install opbeat --save

Initialization

It’s important that the Opbeat agent is started before you require any other modules in your Node.js application - i.e. before http and before your router etc.

This means that you should probably require and start it in your applications main file (usually index.js, server.js or app.js).

Here’s a simple example of how Opbeat is normally required and started:

// add this to the VERY top of the first file loaded in your app
var opbeat = require('opbeat').start({
  appId: '<app id>',
  organizationId: '<org id>',
  secretToken: '<token>'
})

The Opbeat agent will now monitor the performance of your Express application and record any uncaught exceptions.

Advanced configuration

In the above example we initialize the agent by calling the start() function. This function takes an optional options object used to configure the agent. Any option not supplied via the options object can instead be configured using environment variables. So if you prefer, you can set the following three environment variables:

OPBEAT_APP_ID=<app id>
OPBEAT_ORGANIZATION_ID=<org id>
OPBEAT_SECRET_TOKEN=<token>

And then just start the agent like so:

// Start the Opbeat agent before any thing else in your app
var opbeat = require('opbeat').start()

See all possible configuration options in the API documentation.

Full documentation

Performance monitoring

Opbeat automatically measures the performance of your application. It records traces for database queries, external HTTP requests and other slow operations that happens during requests to your app.

By default Opbeat will trace the most common modules. To trace other events, you can use custom traces. For information about custom traces, see the Custom traces in Node.js article.

Traces are grouped in transactions - by default one for each incoming HTTP request. But it’s possible to create custom transactions not associated with an HTTP request. See the Custom transactions in Node.js article for details.

Route naming

The Opbeat agent tracks incoming HTTP requests to your application in what are called “transactions”. All transactions with the same name are grouped together automatically.

In a normal web application you want to name transactions based on the route that matches the incoming HTTP request. So say you have a route to display posts on a blog identified by GET /posts/{id}. You want requests GET /posts/12, GET /posts/42 etc to be grouped together under a transaction named GET /posts/{id}.

If you are using Express, hapi or koa-router this naming happens automatically based on the names of your routes. If you use another framework or a custom router you will see that the transactions are simply grouped together in a few big chunks named “unknown route”. In that case, you will need to help us out a little by supplying a name for each transaction. You can do that by calling opbeat.setTransactionName() at any time during the request with the name of the transaction as the first argument.

Example application using the patterns module for route handling:

var opbeat = require('opbeat').start()
var http = require('http')
var patterns = require('patterns')()

// Setup routes and their respective route handlers
patterns.add('GET /', require('./routes/index'))
patterns.add('GET /posts', require('./routes/posts').index)
patterns.add('GET /posts/{id}', require('./routes/posts').show)

http.createServer(function (req, res) {
  // Check if we have a route matching the incoming request
  var match = patterns.match(req.method + ' ' + req.url);

  // If no match is found, respond with a 404. Opbeat will in
  // this case use the default transaction name "unknown route"
  if (!match) {
    res.writeHead(404)
    res.end()
    return
  }

  // The patterns module exposes the pattern used to match the
  // request on the `pattern` property, e.g. `GET /posts/{id}`
  opbeat.setTransactionName(match.pattern)

  // Populate the params and call the matching route handler
  var fn = match.value
  req.params = match.params
  fn(req, res)
}).listen(3000)

Unknown routes

When viewing the performance metrics of your application on Opbeat, you might see some transactions named “unknown route”. This indicates that the Opbeat agent detected an incomming HTTP request to your application, but didn’t know what to name it.

This might simply be 404 requests, which by design doesn’t match any route, or it might be a symptom that Opbeat wasn’t set up correctly. Make sure we either support your router or that you manually name your routes. If you still can’t get any meaningful metrics to show up, please follow the Troubleshooting Guide.

Error logging

By default the Opbeat agent will watch for uncaught exceptions and send them to Opbeat automatically. But in most cases errors are not thrown but returned via a callback, caught by a promise or simply manually created. Those errors will not automatically be sent to Opbeat. To manually send an error to Opbeat, simply call opbeat.captureError():

var err = new Error('Ups, something broke!')

opbeat.captureError(err)

For advanced logging of errors, including adding extra meta-data to the error, see the API documentation.

Middleware error handler

If you use the connect module and an error is either thrown synchronously inside one of the middleware functions or is passed as the first argument to the middleware next() function, it will be passed to the Connect error handler.

It’s recommended that you register Opbeat as a Connect error handler. In the case where you have multiple Connect error handlers, the Opbeat error handler should be the first in the chain to ensure that it will receive the error correctly.

var opbeat = require('opbeat').start()
var conncet = require('connect')

var app = connect()

// Your regular middleware and router...
app.use(...)
app.use(...)
app.use(...)

// Add the Opbeat middleware after your regular middleware
app.use(opbeat.middleware.connect())

// ...but before any other error handler
app.use(function (err, req, res, next) {
  // Custom error handling goes here
})

Filter sensitive information

By default the Opbeat agent will filter common sensitive information before sending errors and metrics to the Opbeat servers.

It’s possible for you to tweak these defaults or remove any information you don’t want to send to Opbeat:

  • By default the Opbeat agent will not log the body of sampled HTTP requests. To enable this, use the logBody config option

  • By default the Opbeat agent will filter certain HTTP headers known to contain sensitive information. To disable this, use the filterHttpHeaders config option

  • To apply custom filters, use the opbeat.addFilter() function

Add your own data

Opbeat will keep track of the active HTTP request and will link it to errors and recorded transaction metrics when they are sent to Opbeat. This allows you to see details about which request resulted in a particular error or which requests cause a certain HTTP endpoint to be slow.

But in many cases, information about the HTTP request it self isn’t enough. To add even more metadata to errors and transactions, use one of the two functions below:

  • opbeat.setUserContext() - Call this to enrich collected performance data and errors with information about the user/client

  • opbeat.setExtraContext() - Call this to enrich collected performance data and errors with any information that you think will help you debug performance issues and errors

Compatibility

See the Compatibility article for details.

Troubleshooting

If you can’t get the Opbeat agent to work as expected, please follow the Troubleshooting Guide.