Hi
I wondering how many user can open website simultaneously? I mean if you see the number in right corner. Do you guys ever hit like 60 or 70 in one time? Is that okay? What is the maximum to still have a decent speed?
Thanks
It all depends on your server configuration.
And also note that number is an aggregate over time and may not be current. The aggregation time is about 5 minutes.
Let's say i got an dual intel quad core with 16gigs of memory. And it's dedicated server.
Any idea how many simultaneous user can online? Thank you
No, there is no set equation. Depends on your product/site configurations, underlying IO subsystem and many other factors.
Remember that no matter how many cpu's you have nor how much memory, every PHP process is still going to contend for I/O bandwidth to build the Registry for each page (whether from cache or from DB).
Memory is your friend and if you have enough to support the number of users you expect then you can use SHMEM caching which will service the greatest number of users the most efficiently.
We have seen over 100 users online at one point during a promotional sale… That was on our dedicated server… It definetely started to bog down… We do use SHMEM
[quote name='CarStickersDecals' timestamp='1358989825' post='153479']
We have seen over 100 users online at one point during a promotional sale… That was on our dedicated server… It definetely started to bog down… We do use SHMEM
[/quote]
Doesn't sound great, your store loads quickly but there are definitely further modifications you could make to reduce the file size and thus reduce the overhead on the server.
Run a scan of your site using gtmetrix for further optimisation ideas.
[quote name='CarStickersDecals' timestamp='1358989825' post='153479']
We have seen over 100 users online at one point during a promotional sale… That was on our dedicated server… It definetely started to bog down… We do use SHMEM
[/quote]
Thanks for your answer, how to use SHMEM? is that one of the apache service?
SHMEM (shared memory) requires OS support. No shared server will support it. Contact your hosting company. Basically it caches the cache/templates in shared memory rather than on disk or in sqlite.
We've had over 10,000 at peak, running on 7 dedicated servers, MySQL is the biggest bottle neck
I’m hitting 120 to 150 as we speak and server is not liking it very much, but still able to handle it so far, Thank god I just moved to dedicated + SSD + 16 GB.
Update: Ok so we were getting sqlite errors. I turned caching to file now and this has improved performance dramatically, plus no more errors 
We to have been hitting 150 plus users at a time and you can tell that the server is running hard. That's also with SSD's and 16 GB.
We need to figure out how to bring back SHMEM. That made the biggest increase in speed. But not an option in V4.0.X
If someone knows how to implement that cache back in let me know.
I think before you go looking at solutions, that you should characterize the problem properly. Are the accesses all from different IP's? I.e. are they unique users? Or are the majority coming from a single IP address (or block of IP addresses)?
Throwing solution at the wrong problem rarely evern really solves it. It just adds more masking to the real issue.
But maybe you've done that research already and I'm just blowing smoke.
[quote name='tbirnseth' timestamp='1385330298' post='172248']
I think before you go looking at solutions, that you should characterize the problem properly. Are the accesses all from different IP's? I.e. are they unique users? Or are the majority coming from a single IP address (or block of IP addresses)?
Throwing solution at the wrong problem rarely evern really solves it. It just adds more masking to the real issue.
But maybe you've done that research already and I'm just blowing smoke.
[/quote]
Good Point. If we break it down by IP's, segregating the blocks and spammers. We have between 80-100 true active users. And that has been our peak and not on a daily basis… Usually during e-mail blast.
My reason for questioning is that I've seen “Caching proxies” suck down a cs-cart server in no time by trying to do read-ahead to all the links on a page.
I had 170 unique users at a certain moment, and sqlite caching crashed. I switched to file and haven't hit that mark anymore (I did hit >100), but to my surprise my shop and admin are much faster now and it's rock solid. I don't even notice a speed difference with 50 or 5 users online.