PHP error guide

nginx connect failed connection refused: meaning and fix

error server Affects: Current PHP-FPM, Apache 2.4, or nginx Last verified:

Error summary

Start the intended FPM pool or point fastcgi_pass at its actual socket. The configured TCP FastCGI upstream has no accepting listener.

What it means

Start the intended FPM pool or point fastcgi_pass at its actual socket. The configured TCP FastCGI upstream has no accepting listener.

What the error means

This message means that the configured TCP FastCGI upstream has no accepting listener. The exact signature distinguishes nginx connect failed connection refused from a generic application failure.

Why PHP produces it

The engine or service reports “nginx connect failed connection refused” because its required precondition was not met. Start the intended FPM pool or point fastcgi_pass at its actual socket.

PHP version notes

The nginx connect failed connection refused wording here is based on Current PHP-FPM, Apache 2.4, or nginx; punctuation and exception class names can differ on older branches or vendor builds.

Most common causes

  • The immediate input or configuration reaches the specific condition: the configured TCP FastCGI upstream has no accepting listener
  • The code path assumes the prerequisite for nginx connect failed connection refused has already been satisfied.
  • For nginx connect failed connection refused, development and production differ in version, extension, permissions, paths, or service configuration.
  • An earlier operation returned an unchecked value that is consumed by the line reporting nginx connect failed connection refused.

Minimal examples

BAD — reproduces the problem

nginx 
fastcgi_pass 127.0.0.1:9001;

FIXED — safer pattern

nginx 
fastcgi_pass unix:/run/php/app.sock;

Step-by-step diagnosis

  1. Copy the complete “connect() failed (111: Connection refused) while connecting to upstream” text and retain the first application stack frame.
  2. Reproduce nginx connect failed connection refused in the same SAPI and environment listed for this page.
  3. Before changing nginx connect failed connection refused, inspect the preceding value or directive and verify its type, path, version, and permissions.
  4. Apply the narrow correction—start the intended FPM pool or point fastcgi_pass at its actual socket—then repeat the original request once.

Fixes

Correct the failing prerequisite

Start the intended FPM pool or point fastcgi_pass at its actual socket

nginx 
fastcgi_pass unix:/run/php/app.sock;

Fail explicitly at the boundary

Validate the condition before the operation that emits nginx connect failed connection refused, and log a safe diagnostic without credentials or full production paths.

Common mistakes when fixing it

  • Suppressing nginx connect failed connection refused instead of correcting its upstream condition.
  • Testing nginx connect failed connection refused only with the CLI binary when the failing request runs under FPM or Apache.
  • Changing a global setting for nginx connect failed connection refused before confirming the site-specific effective configuration.

How to prevent it

  • Add a focused test that exercises the boundary responsible for nginx connect failed connection refused.
  • Keep runtime versions, extensions, configuration, and deploy artifacts affecting nginx connect failed connection refused reproducible.
  • Validate external data and service return values before they can trigger nginx connect failed connection refused.

Web server / environment notes

fpm, nginx, linux. The failure occurs where the configured TCP FastCGI upstream has no accepting listener

Tags: fpm,nginx,linux

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