Automatic instrumentation is great, but to get the most out of your monitoring you often need to instrument your code. In this article I am going to explain how to instrument a Node.js express app with custom metrics using the Prometheus prom-client package. Although this article specifically addresses Node.js and express, my hope is that the general concepts are applicable to other languages too.

A couple months ago, we launched Profiling in alpha for users on Python and Node.js SDKs — today, we’re moving Profiling for Python and Node.js to beta. Profiling is free to use while in beta — more updates to come when we near GA. Profiling is a critical tool for helping catch performance bottlenecks in your code. Sentry’s profiler gets you down to the exact file/line number in your code that is causing a slow-running query.

Winston Logger is one of the most popular logging libraries for Node.js. It is designed to be a simple and universal logging library supporting multiple modes of transport. A transport is essentially a storage device for the logs. Each logger can have multiple modes of transport configured at different levels. For example, one may want error logs stored in a database, but all logs output to the console or a local file. Some of the features of Winston logger are.

Stack traces show us exactly where an exception occurred, but you can still be left wondering: What arguments or state caused the exception to occur? If you can reproduce the issue locally with a debugger attached you’ll have access to these local variables, but with Sentry you can identify the exception location without needing to reproduce the issue locally. By including local variables with stack traces, Sentry events become much closer to the full debugging experience.

If you want to analyze Mastodon posts, getting them into Apache Kafka® is a sensible first step. Read on to find out how to do this with Typescript and NodeJS.

After a period of beta testing, we're happy to announce the launch of our latest AppSignal for Node.js package. This package features six new integrations and uses the OpenTelemetry framework for reliable telemetry data collection. OpenTelemetry is an open standard that facilitates the instrumentation of standardized telemetry data collection. AppSignal is committed to using OpenTelemetry in new integrations, and our Node.js integration is the first to use the standard.

Profiling is an important tool in every developer’s toolkit because it provides a granular view into the execution of your program from your production environment. This is an important concept, as performance bottlenecks can often be very hard or even impossible to reproduce locally due to external constraints or loads only seen in a production environment.

HTTP is the backbone of all API-centric, modern web apps. APIs are the place where the core business logic of an application lives. As a result, developers spend a lot of time optimizing the API business logic. This article addresses a Node.js developer’s dilemma while debugging an HTTP API request. We take a sample Node.js/Express.js-based HTTP service to demonstrate a new way of debugging Node.js applications using the Lightrun observability platform.