Errors and Logs: Configure Node.js Applications

Retrace does not support APM for Node.js applications but you can capture errors and log and view them within Retrace.  We support both the Winston logging framework and logging directly to our API.  To configure your Node.js project with the Stackify API to send Errors and Logs to Retrace, follow the information below.

Stackify API for Node.js using the Winston Logging Framework page: https://github.com/stackify/stackify-log-winston

Stackify API for Node.js using the Direct Logger page: https://github.com/stackify/stackify-log-nodejs#using-direct-logger

Option 1) Installation with the Winston Logging Framework

Install both packages via npm.

$ npm install stackify-logger
$ npm install winston-stackify

Usage

Using the default logger:

var winston = require('winston');
var stackify = require('stackify-logger');

stackify.start({apiKey: '***', env: 'dev'});

require('winston-stackify').Stackify;

winston.add(winston.transports.Stackify, {storage : stackify});

Instantiating your own logger:

var winston = require('winston');
var stackify = require('stackify-logger');

stackify.start({apiKey: '***', env: 'dev'});

require('winston-stackify').Stackify;

var logger = new (winston.Logger)({
    transports: [
        new (winston.transports.Console)(),
        new (winston.transports.Stackify)(options)
    ]
});

Options

The following options could be passed to the start method:

  • apiKey (Required): Stackify API key
  • env: Environment name. If a Stackify agent is installed, this does not need to be set. If a Stackify agent is not installed, this should be set to the environment name.
  • proxy: HTTP proxy
  • debug: Enables internal debug logging for troubleshooting. Defaults to false.

The Stackify Winston transport takes the following options:

  • storage (Required): Stackify logging library instance. You should specify it directly by passing stackify-logger module instance.
  • level: Level of messages that this transport should log.
  • silent: Boolean flag indicating whether to suppress output, defaults to false.
  • handleExceptions: Property set to false by default for this transport because Stackify Logger Library handles exceptions itself already. If you’re not using default logger and instantiating your own, you don’t need to set this option for Stackify transport.

Troubleshooting

If logging isn’t working, enable internal debug logging for Stackify by setting the debug flag in the Stackify options.

stackify.start({apiKey: '***', env: 'dev', debug: true});

You will see stackify-debug.log in your application’s directory.

Stackify Direct Logger

Option 2) Installation with Stackify Direct Logger

Install the Direct Logger package via npm.

$ npm install stackify-logger

Usage

var stackify = require('stackify-logger');

// this should be executed only once in the app
stackify.start({apiKey: '***', env: 'dev'});

Options

The following options could be passed to the start method:

  • apiKey (Required): Stackify API key
  • env: Environment name. If a Stackify agent is installed, this does not need to be set. If a Stackify agent is not installed, this should be set to the environment name.
  • proxy: HTTP proxy
  • debug: Enables internal debug logging for troubleshooting. Defaults to false.

When calling process.exit(), the stackify-logger will synchronously send log messages that have been queued but not transmitted. Sending via proxy wouldn’t be possible in this case.

Using direct logger

If you are not using Winston logger you can use default Stackify logger. It has 5 levels of messages: tracedebuginfowarn and error. To send the message to Stackify API you should run one of the following methods in any place of your code where you want to track some information:

stackify.log(level, message [, meta])
stackify.trace(message [, meta])
stackify.debug(message [, meta])
stackify.info(message [, meta])
stackify.warn(message [, meta])
stackify.error(message [, meta])

Message: must be a string.

meta: an additional parameter of any type.

Examples of usage:

// Add the module to all the script files where you want to log any messages.
var stackify = require('stackify-logger');

stackify.log('info', 'hey!');
stackify.debug('any message');
stackify.info('any message', {anything: 'this is metadata'});
stackify.warn('attention');
stackify.log('error', {error : new Error()});

When logging an error message you can pass an Error object in metadata like in the last example, so the exception details would be available.

Exception handling

By executing stackify.start() you set a handler for uncaught exceptions. Make sure you run it before any methods that set exception handlers.

Using with Express

Global handler doesn’t work inside Express route methods. You should use error-handling middleware function stackify.expressExceptionHandler. Since middleware is executed serially, it’s order of inclusion is important. Make sure you add it before any other error-handling middleware.

var express = require('express');
var app = express();

/* 
*** block of route handlers ***
*** *** **** **** **** **** ***
*/

app.use(stackify.expressExceptionHandler);

To handle exceptions correctly put this right after all route handlers.

Troubleshooting

If logging isn’t working, enable internal debug logging for Stackify by setting the debug flag in the Stackify options.

stackify.start({apiKey: '***', env: 'dev', debug: true});

You will see stackify-debug.log in your application’s directory.