Tips for debugging "'VariableName' was suspended and it will recompute on the next access."

[cmdcolin]

I am seeing a situation where under heavy load, the app is repeatedly marking via some chain of events, one or more slow (1s+) getters as "suspended" requiring them to be recomputed, which increases load on the app right when i want them to save the day by being cached

I am using

• react 18+strictmode (but also tried with react 17 w/o strictmode)
• mobx-react@9.1.1
• mobx@6.13.1
• mobx-state-tree@5.4.2
• appears to happen in both dev and production (compiled with vite) builds

I haven't made a minimal reproduction yet, but I was wondering if there are any tips for debugging this "issue"?

If there is a strong interest, i can provide instructions to setup the live demo (it is an open source repo) or deploy the production build (but these don't have the trace statements that produce the suspended messages)

[cmdcolin]

I ended up solving this problem by creating a blank autorun similar to the answer here #266 (comment)

my attributes were observed by my app but my hypothesis is that some component was unmounted, and then something or other (it's a data heavy app...) caused a frame to get skipped before remounting happened with the new component that observes the heavyComputation variable, and then it gets marked as suspended. can't confirm though

but, the following fixed it afaict. i just maintain an empty autorun of my variable with

addDisposer(self,autorun(()=>self.heavyComputation))) // where self.heavyComputation is a MST heavy computation getter in our case, and the addDisposer part is only needed for MST