Understanding Node.js EMFILE Error: Too Many Open Files

The EMFILE error indicates that the process has exceeded the maximum number of files it can open simultaneously.

This typically occurs in applications handling many concurrent file operations without proper resource management.

For instance, looping through thousands of files using fs.readFileSync can lead to this error.

To address this, use libraries like graceful-fs that extend Node.js's native fs module to queue file system operations.

Alternatively, use asynchronous methods with concurrency control, such as async.eachLimit.

To increase the system limit for open files, modify the ulimit settings in Linux (ulimit -n 10000).

However, remember that raising limits is only a temporary fix.

Optimize your application to manage file descriptors effectively by closing them as soon as they are no longer needed.