php - Docker multi wordpress vs single architecture multi wordpress - Are the resources used the same? (nginx/mysql/ubuntu)

I have a vps cloud server with around 20 wordpress sites, currently uses nginx to route to the different /var/www/html/wordpresssite . They all share the same mysql server but different login credentials to each of their DBs.

I then implemented on a new vps cloud server (same specs = 2 core + 4GB memory), to try to dockerize all 20 wordpress sites but it seems that the websites become almost unresponsive at times. A few reloads and some of the sites load inconsistently. I followed the instructions here (https://linuxhandbook.com/deploye-multiple-wordpress/).

Just checking to see is it because putting 20 wordpress sites into 20 containers uses a lot more resources as my original method? Is it because we are creating 20 different mysql server instances etc? Or perhaps a configuration error?

Solution:

If you followed the link, you created 20 mysql server instances + 20 wordpress sites + 20 apache servers. Your Nginx server, which acted as a seventh layer reverse proxy, listened on external ports and connected requests to 20 docker containers ... This web servers' structure alone will eat up your vps resources.

If you can live with wordpress multisite + domain mapping plugin, go for it. This deployment consumes fewer resources.

If you have to go with docker, try standalone Nginx setup + single database server container + multiple wordpress containers using x.x.x-fpm-alpine image.