Windsurf Language Server Crashes with "Too Many Open Files" Error

[danielrosehill]

Summary

The Windsurf language server fails to start, reporting a "too many open files" error, despite the system being configured with a high file descriptor limit.

Environment

• OS: Ubuntu 25.04
• Windsurf Version: 1.7.3
• System File Descriptor Limit: 65536
• Launch Method: GUI (via desktop environment)

Issue Details

Upon launching Windsurf, the language server attempts to start but exits immediately with the following error:

Language server failed - too many open files
Error types: (1) *withstack.withStack (2) *withstack.withStack (3) syscall.Errno

This occurs even though the process has the correct limit, as confirmed by:

cat /proc/<PID>/limits | grep "open files"
Max open files            65536                65536                files

Steps to Reproduce

1. Set the system's open file limit to 65536 via ulimit -n 65536 and systemd limits.
2. Launch Windsurf via the KDE menu or GUI session.
3. Observe the crash on language server initialization.

Expected Behavior

The language server should start normally without exceeding system resource limits.

Actual Behavior

The language server crashes immediately, citing "too many open files" even though the process has the correct file limit.

Additional Information

• The issue occurs across multiple projects, even small repositories.
• No unusual symlink loops or excessive open files were detected at runtime.
• Problem appears isolated to language server startup logic.

Excerpt from Diagnostic Logs

2025-05-03 17:04:21.356 [info] Starting language server process with pid 13137
2025-05-03 17:04:21.357 [info] Language server failed - too many open files
2025-05-03 17:04:21.357 [info] Error types: (1) *withstack.withStack (2) *withstack.withStack (3) syscall.Errno
2025-05-03 17:04:21.365 [ERROR]: Language server exited with code 1
2025-05-03 17:04:21.368 [ERROR]: Failed to start language server: Error: Language server exited before sending start data

Recommendation

Please investigate whether the language server is:

• Spawning too many file watchers prematurely
• Leaking file descriptors
• Handling filesystem structure inefficiently (e.g., scanning massive .git/node_modules trees)

[anantn]

ulimit will only temporarily change the open file limit value for the current terminal session you are in and does not affect the windsurf-server's limit.

To change global process limits, edit /etc/sysctl.conf as add a line:

fs.file-max = 65536

Edit /etc/security/limits.conf and add a line:

*               soft    nofile          65536

If there are files in /etc/security/limits.d you need to check if there's no override for this value in one of those files.

Restarting should fix the problem.

[jtbr]

Initial startup of Windsurf 1.9.2 after first authentication is failing with this error on my Linux Mint 21.3 box.

It appears the limits are not limiting: sysctl shows:
fs.file-max = 9223372036854775807

$ ulimit -Hn
1048576
$ ulimit -Sn
1024

Perhaps this is relevant?
fs.protected_hardlinks = 1
fs.protected_symlinks = 1
(although I tried turning them off with sysctl and nothing changed, so probably not)

Here's the log:

"2025-06-03 16:32:07.866 [info] 2025/06/03 16:32:07 maxprocs: Leaving GOMAXPROCS=16: CPU quota undefined",
"2025-06-03 16:32:07.947 [info] I0603 16:32:07.947326 4027990 main.go:585] Setting GOMAXPROCS to 4",
"2025-06-03 16:32:07.957 [info] I0603 16:32:07.956875 4027990 main.go:800] Starting language server process with pid 4027990",
"2025-06-03 16:32:07.957 [info] I0603 16:32:07.956916 4027990 server.go:269] Language server will attempt to listen on host 127.0.0.1",
"2025-06-03 16:32:07.957 [info] I0603 16:32:07.957108 4027990 server.go:276] Language server listening on random port at 40651",
"2025-06-03 16:32:07.957 [info] F0603 16:32:07.957159 4027990 main.go:803] Language server failed - too many open files",
"2025-06-03 16:32:07.957 [info] (1) attached stack trace",
"2025-06-03 16:32:07.957 [info]   -- stack trace:",
"2025-06-03 16:32:07.957 [info]   | github.com/Exafunction/Exafunction/exa/language_server/user_settings.NewUserSettingsManager",
"2025-06-03 16:32:07.957 [info]   | \texa/language_server/user_settings/user_settings.go:174",
"2025-06-03 16:32:07.957 [info]   | [...repeated from below...]",
"2025-06-03 16:32:07.957 [info] Wraps: (2) attached stack trace",
"2025-06-03 16:32:07.957 [info]   -- stack trace:",
"2025-06-03 16:32:07.957 [info]   | github.com/Exafunction/Exafunction/exa/fs/file_watcher.NewFileWatcherDefault",
"2025-06-03 16:32:07.957 [info]   | \texa/fs/file_watcher/file_watcher.go:103",
"2025-06-03 16:32:07.957 [info]   | github.com/Exafunction/Exafunction/exa/fs/file_watcher.NewFileWatcher",
"2025-06-03 16:32:07.957 [info]   | \texa/fs/file_watcher/file_watcher_factory.go:9",
"2025-06-03 16:32:07.957 [info]   | github.com/Exafunction/Exafunction/exa/language_server/user_settings.NewUserSettingsManager",
"2025-06-03 16:32:07.957 [info]   | \texa/language_server/user_settings/user_settings.go:172",
"2025-06-03 16:32:07.957 [info]   | github.com/Exafunction/Exafunction/exa/language_server.CreateLanguageServerAndServe",
"2025-06-03 16:32:07.957 [info]   | \texa/language_server/server.go:346",
"2025-06-03 16:32:07.957 [info]   | main.main",
"2025-06-03 16:32:07.957 [info]   | \texa/cmd/language_server/main.go:801",
"2025-06-03 16:32:07.957 [info]   | runtime.main",
"2025-06-03 16:32:07.957 [info]   | \tGOROOT/src/runtime/proc.go:283",
"2025-06-03 16:32:07.957 [info]   | runtime.goexit",
"2025-06-03 16:32:07.957 [info]   | \tsrc/runtime/asm_amd64.s:1700",
"2025-06-03 16:32:07.957 [info] Wraps: (3) too many open files",
"2025-06-03 16:32:07.957 [info] Error types: (1) *withstack.withStack (2) *withstack.withStack (3) syscall.Errno",
"2025-06-03 16:32:07.967 [info] (Windsurf) 2025-06-03 16:32:07.967 [ERROR]: Language server exited with code 1",
"2025-06-03 16:32:07.971 [info] (Windsurf) 2025-06-03 16:32:07.968 [ERROR]: Failed to start language server: Error: Language server exited before sending start data",
"2025-06-03 16:32:07.971 [info] (Windsurf) 2025-06-03 16:32:07.971 [ERROR]: LS startLanguageServer error: Language server exited before sending start data"