How to reproduce

1. Edit the Dockerfile in order to select the desired PHP version

2. Build the image and start the stack
   This will create some classes on the fly (see generate_classes.php for details)

   docker-compose up --build 

3. Create some load

   ab -n 1000 -c 10 http://localhost:8080/

4. Monitor the memory usage

   docker stats

5. Repeat with another PHP version

My results

php:8.0.27-fpm-alpine

• Directly after start: 6.301MiB
• After one request: 9.5MiB
• After 1,001 requests: 37.05MiB
• After 11,001 requests: 37.05MiB

php:8.1.14-fpm-alpine

• Directly after start: 6.633MiB
• After one request: 15.77MiB
• After 1,001 requests: 59.54MiB
• After 11,001 requests: 274MiB