Chapter 2. Features

The diagnostic report functionality is available as a stable feature in Node.js 14 LTS. In earlier releases of Node.js, the functionality was available as Technology Preview.

This feature enables you to generate diagnostic reports for anomalies, such as, performance issues, memory leaks, high CPU usage, and so on. The report is in JSON format. The report uses the first failure data capture (FFDC) technology. This technology captures diagnostic data at the time when the error occurs.

The V8 JavaScript engine has been upgraded to v8.4. The engine contains new features, such as, optional chaining and API changes that provide better localization support.

You can add metering labels to your Node.js pods and check Red Hat subscription details with the OpenShift Metering Operator.

Node.js should use the following metering labels:

See Metering documentation for more information.

For more information on labels, see Understanding how to update labels on nodes.

International Components for Unicode (ICU) supports internationalization and globalization of software applications. It provides support for many languages and locales. It simplifies the development and deployment of software applications in all languages.

From Node.js 14 LTS, the full-icu option is enabled by default. This option enables full ICU data set. For more information about the full-icu option, see Internationalization support.

In previous releases of Node.js, only English data set was enabled by default. You had to perform additional steps to get and enable support for other locales.

If you require support for English only and you want to save disk space by removing the full ICU data set, enter the following command as the root user:

# dnf remove nodejs-full-i18n

The Red Hat build of Node.js for s390x and ppc64le platform is supported only in OpenShift environments provisioned on IBM Z and IBM Power Systems infrastructure. Running a Node.js application on a stand-alone installation of RHEL on IBM Z and IBM Power Systems is not supported.

New images for products supported on IBM Z and IBM Power Systems are available in the Red Hat Container Catalog.

For more information about deploying Node.js applications on OpenShift provisioned on IBM Z and IBM Power Systems infrastructure, see the section Example applications for Node.js.

Opossum is a circuit breaker for Node.js. Red Hat build of Node.js provides a fully supported @redhat/opossum module.

The circuit breaker pattern is used to reduce the impact of network failure and high latency on service architectures, where services asynchronously invoke other services.

The @redhat/opossum module is available for download from the Red Hat Customer registry. The modules with the @redhat namespace should be downloaded from the Red Hat registry and all the other modules should be downloaded from the npm registry. To specify the download paths, create a .npmrc file in the root directory of your application with the following code:

@redhat:registry=https://npm.registry.redhat.com
registry=https://registry.npmjs.org

After specifying the download paths, to install the @redhat/opossum module in your application enter the following command:

$ npm install @redhat/opossum

To work with the @redhat/opossum module add the following code to your application:

const CircuitBreaker = require(‘@redhat/opossum’)

The AsyncLocalStorage class creates an asynchronous state in callbacks and promise chains. Use the class to store data in these asynchronous states.

The WebAssembly packages for Node.js improve performance and cross-platform support.

The new WASI APIs provide an implementation of the WebAssembly System Interface specification. Use this interface for sandboxed execution of WebAssembly applications. Using the interface, the applications also get access to the underlying operating system.

In earlier releases of Node.js, a warning message was returned when EcmaScript modules were used in the applications. The warning message indicated that the EcmaScript modules are experimental features.

From Node.js 14 LTS onward, the warning message has been removed. However, note that the EcmaScript modules are still available as Technology Preview.