What is Tracing in Node.js?

 Tracing provides a mechanism to collect tracing information generated by V8, Node core and userspace code in a log file. Tracing can be enabled by passing the --trace-events-enabled flag when starting a Node.js application.

Image for post

The set of categories for which traces are recorded can be specified using the --trace-event-categories flag followed by a list of comma separated category names. By default the node and v8 categories are enabled.

Running Node.js with tracing enabled will produce log files that can be opened in the chrome://tracing tab of Chrome.

Comments

Post a Comment

Popular posts from this blog

What is a Callback function in Node.js?

Image
  Node.js, being an asynchronous platform, doesn’t wait around for things like file I/O to finish — Node.js uses callbacks. A callback is a function called at the completion of a given task; this prevents any blocking, and allows other code to be run in the meantime. Callbacks are the foundation of Node.js. Callbacks give us an interface with which to say, “and when you’re done doing that, do all this.” This allows us to have as many IO operations as our OS can handle happening at the same time. For example, in a web server with hundreds or thousands of pending requests with multiple blocking queries, performing the blocking queries asynchronously gives you the ability to be able to continue working and not just sit still and wait until the blocking operations come back.
Read more

What is an Event loop in Node.js and how does it work?

Image
  An event loop in Node.js handles all the asynchronous callbacks in an application .  It is one of the most important aspects of Node.js and the reason behind Node.js have non-blocking I/O. Since Node.js is an event-driven language, you can easily attach a listener to an event and then when the event occurs the callback will be executed by the specific listener. Whenever functions like setTimeout, http.get, and fs.readFile are called, Node.js executed the event loop and then proceeds with the further code without waiting for the output. Once the entire operation is finished, Node.js receives the output and then executes the callback function. This is why all the callback functions are placed in a queue in a loop. Once the response is received, they are executed one by one.
Read more