I am currently on DreamHost Shared hosting (Happy Hosting) and considering moving my domains to VPS. The one thing that concerns me most are the various posts I've read about VPS being slower to serve pages than shared hosting.
My most active domain (and the one pretty much forcing me to migrate to VPS) is primarily accessed by external "Digital Users". Those are other computers and software systems that access the web site programmatically. There are pages accessed by humans too, but almost 95% of the site's usage is due to the external digital user requests.
For example, there are roughly 7000 "devices" living inside servers owned and operated by another company. Those "devices" are actually program modules that are installed on the external servers. Each one makes as many as 500 requests per day, but the average is more like 30 per day.
The real problem is that several hundred of those device might try and query my domain at all once. Of course the usual is that they don't. But there are times when it seems like every one of those devices decides to squeeze through the front door at the same time.
On shared hosting, the ProcWatch daemon is periodically killing responses to those requests because the domain user has too many active processes running. I believe that moving to VPS will allow me to handle all those requests (and many more as this product continues to succeed).
So, question time:
1) Will VPS allow me to run as many processes as needed when those peak usage moments occur?
2) When migrating from Shared Hosting to VPS hosting, I see that I can discontinue my existing plan once everything has migrated to the new VPS. Will I still be able to use shared MySQL even after canceling my shared hosting plan?
3) Has anyone had issues with the initial migration from Shared to VPS Hosting?
I'm sure there are other questions I would like to ask, but these three will work for now. Any experience, information, suggestions or tips you can offer .. please do so. Thank you in advance.