How many simultaneous users can this VPS server handle?

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The discussion revolves around the capacity of a VPS server to handle simultaneous users, with specifications including an AMD EPYC 9634, 8 GB DDR5 RAM, 4 dedicated cores, and a 256 GB NVMe SSD. Willy inquires about the theoretical user limit and whether the Discourse Docker container utilizes the hardware natively. Ethsim2 points to relevant settings in the app.yml file, such as UNICORN_WORKERS and db_shared_buffers, which can impact performance. However, Ed_S suggests that there is no definitive answer, as the limit depends on usage patterns, history, and variables like active users, posts, and thread length. Ed_S proposes considering factors like weekly active users, concurrent users, and post volume to estimate the required resources, and recommends either upsizing the machine as needed or seeking guidance from similar forums.

1

How many simultaneous users could this VPS server theoretically handle?

AMD EPYC™ 9634
8 GB DDR5 RAM (ECC)
4 dedicated cores
256 GB NVMe SSD

And that brings me to another important question, does the Discourse Docker container take advantage of all hardware natively or do I have to touch configurations?

3

i think in the app.yml, there are two relevant settings

in the env section,


## How many concurrent web requests are supported? Depends on memory and CPU cores.
## Will be set automatically by bootstrap based on detected CPUs, or you can override
UNICORN_WORKERS: 4

in the params section,

## Set db_shared_buffers to a max of 25% of the total memory.
## will be set automatically by bootstrap based on detected RAM, or you can override
db_shared_buffers: "1GB"

## can improve sorting performance, but adds memory usage per-connection
#db_work_mem: "40MB"


## maximum upload size (default: 10m)
upload_size: 20m

i would be interested to understand the answer to your question in respect to these settings.

4

I don’t think there’s an answer to the question, really - it depends on usage patterns, mostly, and to some extent on history.

There won’t be any hard limit.

Mostly what you will notice is response times increasing as the number of simultaneous users increases. If you have very peaky traffic - like for live sports events - then you’ll need more resources.

As your forum history gets deeper, with more accumulated posts from more accounts, each database operation will get a bit slower and will need more resources. Similarly if you have very very long threads.

So, how many users active in a week, how many active together in a minute, how many tens of thousands of posts, those are the variables you might look at.

I think there are only a few ways to do this

  • spend the maximum amount of money on the best possible machine and hope
  • buy a reasonable machine and keep upsizing it whenever it is shown to be too small
  • ask people who run similar forums what their forum statistics are and what their systems are like.

Edit: see also this recent technical thread