IIS PHP7 FastCgi Intemittent HTTP Error 500.0 - Internal Server Error

Question

I'm running PHP7 under IIS8.5 with FastCGI

IIS is returning the following error occasionally:

HTTP Error 500.0 - Internal Server Error

C:\PHP\php-cgi.exe - The FastCGI process exited unexpectedly

IIS logs the errors as in the following example

2021-05-05 13:22:20 10.10.0.15 GET /pedido/status1.php - 443 - 152.250.143.188 Mozilla/5.0+(Windows+NT+10.0;+Win64;+x64)+AppleWebKit/537.36+(KHTML,+like+Gecko)+Chrome/90.0.4430.93+Safari/537.36 https://www.***.com/pedido/pedido2.php 500 0 255 2718

FastCgi properties are the following:

• Instance MaxRequests: 10000
• Max Instances: 0
• Standard Error Mode: ReturnStdErrIn500
• Activity Timeout: 90
• Idle Timeout: 300
• Queue Length: 1000
• Rapid Fails per Minute: 10
• Request Timeout: 90

I appreciate any help that can tell us if we are misconfigurating IIS

Tks in advance

Answer 1

There are many reasons for this error, you can try the solution below:

1. There's a fairly good chance you're missing the correct VC++ runtime for the version of PHP you're running, try installing VC++ runtime .

2. If you have installed the VC++ runtime, please check whether you have installed 32-bit or 64-bit.

Answer 2

Your Rapid Fails PerMinute is too low.

Just change the Rapid Fails PerMinute to the default of 90,

Rapid Fails PerMinute: Specifies the maximum time allowed for a request to the application. If a FastCGI process takes longer than the specified time on a single request, it is terminated. The default value is 90 seconds.