odoo server requirement/concurrent login
The concurrency login in is not problem, for performance is about concurrently click buttons.
If 100 users are reading a document in odoo, none of them are logged in. Once they click a button to move to another document they are logged in but are immediately logged out until they click another button.
odoo is using Python language and Postgres database, the performance is base on server.
With that amount of user concurrency you need to have as much as ram and cpu cores that you could get, let's said that you have 32gb, and 10 cpu cores, you need to config Odoo to use this resources as best as it could using workers that enables multiprocesing. For resource config in Odoo such as ram and cpu cores you need to determine what number of workers do you need in others servers like gunicorn the formula is workers = cores * 2 + 1,
In order to increase the performance of an Odoo instance, need to:
a fast disk drive for storage (preferably SSD)
a Linux VPS with lots of RAM.
activate multiprocessing mode in Odoo.
configure and optimize the PostgreSQL service properly.
Install Odoo on a VPS with more RAM because Odoo is known as resource intensive application, and load the entire Odoo instance and its database into RAM if possible. Solid state disk drives excel especially in random access and they can achieve random access IOPS hundreds of times higher than conventional mechanical har disk drives because SSDs do not have any moving parts. No matter how much optimizations and configurations do on Odoo, if the server is not fast or powered by SSD, Odoo will be slow. Getting the right hosting for your Odoo is the most important factor of your Odoo’s performance.There are other optimisation can be done.
digitalocean.com provide VPS server start with SSD storage, register from this link digitalocean.com you will receive $10.00 credit.