File Descriptor Exhaustion Limits Scalability

8/10 High

NGINX's scalability is constrained by the operating system's maximum file descriptors (FDs), which commonly defaults to 1024. As a reverse proxy, NGINX consumes at least 2 FDs per request (client + upstream server), causing rapid FD depletion and hard connection failures at high concurrency if not manually increased via `worker_rlimit_nofile`.

NGINX
Category
config
Workaround
solid
Stage
deploy
Freshness
persistent
Scope
single_lib
Upstream
open
Recurring
Yes
Maintainer
active

Sources

Collection History

Query: “What are the most common pain points with Nginx for developers in 2025?”4/4/2026

the operating system's maximum number of File Descriptors (FDs) available to each process...the ultimate bottleneck is the OS limit, which commonly defaults to 1024...When NGINX operates as a reverse proxy, it consumes at least two FDs per request (one for the client, one for the upstream server).

Created: 4/4/2026Updated: 4/4/2026