EMFILE errors indicate too many open files. Increasing system limits or optimizing file handling can help resolve this issue.

The 'EMFILE' error, meaning 'too many open files,' occurs when a Node.js application attempts to open more file descriptors than the operating system allows. This is often the result of opening files in rapid succession or not properly closing them after use. To resolve this, first increase the file descriptor limit on your system; on Unix-like systems, this can be done with ulimit -n <limit>, though it's essential to consider the long-term scalability of your app rather than just increasing limits. Additionally, review your code for file handling practices, ensuring that each fs operation includes a matching close call after file use. Utilizing fs.promises methods or fs.createReadStream in asynchronous patterns can also prevent the app from opening too many files at once. Libraries like graceful-fs offer improved management of file descriptors, helping applications handle burst traffic without overwhelming system limits. Another approach is to add a queue for file operations, which prevents too many files from opening simultaneously by managing file operations in a sequence. Long-term, optimizing file I/O practices and file descriptor usage will prevent repeated EMFILE errors as your application scales.