Simple SvelteKit deploy on Page exceeds CPU because one server side call

[stefan15]

I was following the tutorial to deploy SvelteKit website through pages.
I have one +page.server.ts file where I load some json data from a public api (for test reasons).

import type { PageServerLoad } from './$types';
export const load = (async ({ fetch, params }) => {

    const all_ep_res = await fetch('https://syntax.fm/api/shows');
    const all_ep_data = await all_ep_res.json();

    return {
        episodes: all_ep_data
    };
}) satisfies PageServerLoad;

So I deployed this, and tried to browse to this page.

After two clicks I got:

This is a very simple api call; CPU exceeded because of this?

[KianNH]

@stefan15

This is a very simple api call; CPU exceeded because of this?

The CPU time is likely from calling .json() which is having to parse the ~3.3MB of JSON returned by the API you’re calling.

See if you can reduce the amount of data returned - i.e with a limit or pagination.

[stefan15]

In this case, this could be a possibility; but I guess there are situations where you need to process such large list…

Is there a way to avoid such “exceed” up front?

[KianNH]

Workers on the free plan are limited to 10ms of CPU time and the paid plan has two usage models - Bundled which has 50ms and Unbound which has up to 30 seconds but you are billed for wall-time duration when using Unbound.

Bundled sounds like it should work fine for your use-case if you upgrade? But otherwise, other than not calling json(), I can’t think of any real workaround.

[stefan15]

And how do you “choose” between the two usage models; If I see to the paid plan, I see both, but not sure how I should select one or the other, or is this something you need to configure?

[stefan15]

Found in the docs that you can configure it; of course, the SvelteKit deployment does not uses explicit worker functions; it’s baked into the “adapter”. So not sure if 50ms of CPU is “enough” in this case?

[KianNH]

@stefan15

And how do you “choose” between the two usage models; If I see to the paid plan, I see both, but not sure how I should select one or the other, or is this something you need to configure?

For the Pages project, go into Settings and then Functions.

@stefan15

the SvelteKit deployment does not uses explicit worker functions; it’s baked into the “adapter”.

Svelte just compiles all of your routes into a Worker on your behalf - it shouldn’t really make a difference.

[stefan15]

So if, for some reason, the http cpu time is larger than 50ms, the site goes down because of the CPU exceeding limations; how long will it be down, or only for that specific IP/user, all users?

[KianNH]

Workers (and by extension Functions) are invoked on request - if the CPU limit is reached, that only impacts that specific request. They can just refresh the browser and try again.

[stefan15]

Ok, thank you for the very clear feedback! It was helpful.