1- For 3000+ users accessing the site We used 16 GB ram with Quad core server
2- as @kolate_sambhaji said Frappe take care of all dependency
3- Drop box and Aws but i hoped to learn how to configure Database replication on other servers @rmehta
4-Server with 16GB ram and Quad core stress test result gave us
–100000 login process done in less than 1 min (Bandwidth error shown in for more data)
–8000 file upload with 500 kb size in less than 1 min (Ram load show with more data)
thies stress test made by me hitting local server and gave almost the same result on Digitalocean droplet
5- Attachment Module (Allow all kind of files to be uploaded) Major security concern
can be fixed by adding the right validation (White list or Black list files) in hooks
i will share my code when it finished
6- Can we lock the front end server from privileged users ?
7- Can we lock the front end server front changes on the SW level ?
No, in case of stopping the site from nginx rest app stop (i read frappe blog about the architecture they want to achieve by separating system component on several servers but unfortunately it not implemented yet … hope to hear about it soon )
and i still think frappe framework is one of the best system i worked with .
and i will still recommend it to my clients and employers ,
please correct me if missed in any points .
best regards
Ahmad