When will "Uncollected Garbage" be deleted?

[thepaul]

@Toyoo

I like it. One nitpick to a comment:

	// SetExpiration sets an expiration time for the given piece ID on the given satellite. If pieceSize
	// is non-zero, it may be used later to decrement the used space counters without needing to call
	// os.Stat on the piece.

The OS does have to read the inode on unlink, but of course it unfortunately doesn’t return any of the info from the deleted inode to the unlink caller. We have to call stat separately. I’m not sure why a subsequent unlink doesn’t read the inode from cache at that point, but some profiling (on ext4+linux) suggests that it does not, in at least some cases. Maybe for something like a delete, a cached inode is not good enough? I haven’t gone into depth here.

@Toyoo

I would also be worried about the default size of the LRU cache, 1000 is close to a popular default of 1024 of max open files per process on many systems. Though with golang liking I/O they might have solved it in a different way

This hadn’t occurred to me. I was under the impression most people ran their nodes with a much higher RLIMIT_NOFILE. Is 1024 even enough to run a fair-sized node in normal operation?