server-configs-nginx/h5bp/web_performance/cache-file-descriptors.conf

# ----------------------------------------------------------------------
# | Cache file-descriptors                                             |
# ----------------------------------------------------------------------

# This tells Nginx to cache open file handles, "Not Found" errors and
# metadata about files and their permissions.
#
# Based on these cached metadata, Nginx can immediately begin sending data when
# a popular file is requested, and will also know to immediately send a 404 if a
# file is missing on disk, and so on.
#
# (!) It also means that the server won't react immediately to changes on disk,
#     which may be undesirable.
#     As only metadata are cached, edited files may be truncated until the cache
#     is refreshed.
#     https://github.com/h5bp/server-configs-nginx/issues/203
#
# In the below configuration, inactive files are released from the cache after
# 20 seconds, whereas active (recently requested) files are re-validated every
# 30 seconds.
# Descriptors will not be cached unless they are used at least 2 times within
# 20 seconds (the inactive time).
# A maximum of the 1000 most recently used file descriptors can be cached at
# any time.
#
# Production servers with stable file collections will definitely want to enable
# the cache.
#
# https://nginx.org/en/docs/http/ngx_http_core_module.html#open_file_cache

open_file_cache max=1000 inactive=20s;
open_file_cache_valid 30s;
open_file_cache_min_uses 2;
open_file_cache_errors on;