We have an Azure App Service that makes use of the Redis PHP extension. Both the App Service and extension are PHP 5.6 / 32-bit. We are loading the PHP extension from a settings.ini
in accordance with the Azure documentation.
extension = "d:\home\site\wwwroot\ext\php_redis.dll"
Once every few weeks the App Service will fail to load the extension and the site breaks. We receive the following error in our logs:
[06-Nov-2016 17:25:42 America/Los_Angeles] PHP Warning: PHP Startup: Unable to load dynamic library 'd:\home\site\wwwroot\ext\php_redis.dll' - %1 is not a valid Win32 application. in Unknown on line 0
This problem will go away on its own some hours later, presumably when the app service restarts or is migrated to another VM. We have an identical 'secondary' app service in a different region that never exhibits this problem.
Has anyone seen this sporadic failure? How can it be prevented?