Should Wordpress slow down and throw 502 and 504 errors , when 5-6 people simultaneously are making bulk edits on the site on different/separate accounts? It's a Woocommerce site with 600 products on each language, based on Multisite + MultilingualPress. I'm wondering if this is Wordpress fault, or maybe some plugins cause this overload?
Yes and no. Servers only have so many resources to work with, and bulk edits are expensive requests.
Lets take an analogy:
You're a secretary, and somebody asks you to modify modify the title of 400 reports. Doing it once might take 2 seconds, but 400x2 is 800 seconds or ~14 minutes.
Another part of your job as a secretary is that you only have so much time given to do the task, 20 minutes, and you can only keep track of so many documents at a time.
The next day, 5 people ask you to change the title on 400 reports. That's 2000 documents that need to be changed, and only 20 minutes to do it. You're slowed down by the process, and 2 people get their wish but it's done slowly, you can only work so fast!
The other 3 people don't get their wish though, you throw your arms up and give the international code for "too much! I can't take it" which is the number 503! If there was a go between, they might pass on the international code for "I asked them something but I'm not hearing anything back", also known as 504
Now, you can improve this several ways:
- a more powerful server or servers
- reducing the overhead of plugins ( this will involve extensive profiling and investigation on your part and isn't something that I can help with in the format of this site )
- bulk editing fewer posts at a time
- not doing multiple bulk edits at the same time
Like humans, servers can only keep track of so much at a time, their RAM and processing speed isn't infinite