Feature request: Allow disabling file handle limit warning

[Taytay]

** Problem **
I am running in a linux environment that doesn't allow me to bump the file limit above 8192. As a result, every invocation of pants gives me the warning:

File handle limit is capped to: 8192. To avoid 'too many open file handle' errors, we recommend a limit of at least 10000: please see https://www.pantsbuild.org/docs/troubleshooting#too-many-open-files-error for more information.

Describe the solution you'd like
I looked at the source code to see if there was an env variable or setting to disable it, but I couldn't find it. I'm too new to pants to know what the convention is for this sort of thing, but it would be great to be able to acknowledge/suppress this.

[huonw]

Ah, yes, this would be annoying.

It sounds like you might've found where this is defined:

pants/src/rust/engine/fs/src/lib.rs

Lines 731 to 760 in 8ba6ea2

	pub fn increase_limits() -> Result<String, String> {
	loop {
	let (cur, max) = rlimit::Resource::NOFILE
	.get()
	.map_err(|e| format!("Could not validate file handle limits: {e}"))?;
	// If the limit is less than our target.
	if cur < TARGET_NOFILE_LIMIT {
	let err_suffix = format!(
	"To avoid 'too many open file handle' errors, we recommend a limit of at least {TARGET_NOFILE_LIMIT}: \
	please see https://www.pantsbuild.org/docs/troubleshooting#too-many-open-files-error \
	for more information."
	);
	// If we might be able to increase the soft limit, try to.
	if cur < max {
	let target_soft_limit = std::cmp::min(max, TARGET_NOFILE_LIMIT);
	rlimit::Resource::NOFILE
	.set(target_soft_limit, max)
	.map_err(|e| {
	format!("Could not raise soft file handle limit above {cur}: `{e}`. {err_suffix}")
	})?;
	} else {
	return Err(format!(
	"File handle limit is capped to: {cur}. {err_suffix}"
	));
	}
	} else {
	return Ok(format!("File handle limit is: {cur}"));
	};
	}
	}

That's called from

pants/src/rust/engine/src/externs/interface.rs

Line 695 in 8ba6ea2

match fs::increase_limits() {

Which is called from

pants/src/python/pants/engine/internals/scheduler.py

Line 227 in 8ba6ea2

self._py_scheduler = native_engine.scheduler_create(

Three options to address this might be:

1. use [GLOBAL].ignore_warnings: https://www.pantsbuild.org/2.20/reference/global-options#ignore_warnings to silence this (although I'm not 100% sure this'll work...)
2. convert TARGET_NOFILE_LIMIT into a global option (with default 10000) that's passed down, so it can be customised when the env has a lower limit, e.g. target_file_handle_limit = 8192
3. add a boolean option to silence this warning specific, e.g. allow_file_handle_limit_below_target = true or something.

I'm not sure what's best. Can you make 1 work?

[Taytay]

Ah cool - I can give one of these a shot and see if they work. Thanks!