Blocking controller instrumentation

[Prinzhorn]

Is there a node equivalent to this https://docs.newrelic.com/docs/ruby/blocking-controller-instrumentation ?

I've set up Availability monitoring but the ping tampers with the stats (much more requests, much less errors, much less response time etc). How do I create a connect/express route which will not be tracked? E.g. sth. like a middleware which I can add to the routes:

var newrelic = require('newrelic/utils');

//......

app.get('/ping', newrelic.doNotTrack(), pingController);

[othiym23]

something like this should do the trick:

var newrelic = require('newrelic');

// ...elsewhere...
function pingController(req, res, next) {
  newrelic.setIgnoreTransaction(true);

  // ...other pingController stuff...

  next();
}

// ...elsewhere...
app.get('/ping', pingController);

You could probably create a quick and dirty middleware to call setIgnoreTransaction(true) for you if you need to use it for a bunch of routes. Something to keep in mind is that even if you disable the agent via configuration, the module will still export a stub API, so you don' t have to put the New Relic API calls in conditional blocks.

Let us know if that doesn't work!

[Prinzhorn]

Looks great, thanks. Two questions though

1. I'm currently doing this

if(process.env.NEW_RELIC_LICENSE_KEY) {
    require('newrelic');
}

is it correct to remove the if-block and instead set NEW_RELIC_ENABLED to false in dev/test env?

2. I assume it's save to require the module multiple times, right? Because I'd need to require it a second time inside the middleware.

[othiym23]

1. is it correct to remove the if-block and instead set NEW_RELIC_ENABLED to false in dev/test env?

Yes. Just make sure that you set it before you require('newrelic')

2. I assume it's save to require the module multiple times, right? Because I'd need to require it a second time inside the middleware.

Yes, the module bootstraps a single agent / API and then returns the same object each time you require the module.

[Prinzhorn]

Just wanted to let you know it seems to work as expected.

Route definition:

app.get('/ping', ignoreNewrelic(), controllers.web.ping);

ignoreNewrelic middleware:

var newrelic = require('newrelic');

module.exports = function() {
    return function(req, res, next) {
        newrelic.setIgnoreTransaction(true);
        next();
    };
};

Ping controller:

module.exports = function(req, res, next) {
    res.end('pong');
};

[othiym23]

Great! BTW, you don't need ignoreNewrelic to be a generator, because it's not capturing anything in the closure. You can just write it as

var api = require('newrelic');
module.exports = function (req, res, next) {
  api.setIgnoreTransaction(true);
  next();
}

Glad it's working for you!