Is the server script associated with an SSP app initialized on every request? If I set up a function to store something in a global variable, could a different user hitting the same SSP app access it or is each request and/or user isolated? I’m trying so understand the context.

Each time you hit a service or ssp file, the libraries get evaulated, then the actual ss/ssp gets evaluated. Tje execution is isolated on a session basis as a classic server side web language/framework (think PHP for example) . That being said, if your service or SSP file sets a caching flag on the response, then this becomes the same response for everybody hitting that url. The URL will be stored in a CDN and next time somebody hits that service, most likely it would be served from there and not from NetSuite.

That makes sense. So the libraries are evaluated on every hit. I was pretty confident on the rest of the process but uncertain about the libraries “global context”. That tells me there could be an argument for keeping the libraries light and splitting functionality across multiple Apps if necessary. It’s not like a NodeJs app that cold starts once. It sounds like your saying each request is a cold start for the environment. Very interesting. I wonder why it’s built this way. It seems really resource intensive.

I think there are multiple phases in the evaluation of libraries, some most likely are cached (the parsing of the JS files, for example) but the execution itself isn't (so every define() you see actually runs the define function every time and when you require it the inside gets evaluated, etc... ). So i'd say it's a "warm" (not hot) start. There's not much info on this and it might be wrong and it's mostly based on empirical evidence, some knowledge about NS... I think for the full SCA code, the evaluation of all the libraries code takes about 200ms of execution for example, on a warm run - which also includes for example reading configuration (which is a query to a record, but that also is heavily cached by NS)

Makes sense. JavaScript is fast as long as the resources are available. I haven’t found much documented on it either. I run all requests to NetSuite through a load balancer and reverse proxy so I’ve hit a lot of fringe cases over the years. If we only had more time to play:-) thanks for the feedback

well, SSPs and all NS server JS runs in rhino (or it has historically been rhino and changed in the last release(s). ) So it’s not super fast but for our use cases i don’t think it’s particularly slow either.