Support for incremental SSG (ISG/ISR)

[joostmeijles]

It seems that next-on-netlify current does not support incremental SSG (https://nextjs.org/docs/basic-features/data-fetching#incremental-static-regeneration).

Are there any plans to support this?

[cassidoo]

This package actually does support it, to an extent!

Here's a demo:
https://sonnet-18-incremental.netlify.app/

You can use these URLs in the box there for the demo:
https://github.com/cassidoo/next-netlify-starter
https://github.com/netlify/next-on-netlify

Here's the code for it:
https://github.com/cassidoo/sonnet-18/blob/static-props/pages/compare/%5B...slug%5D.js

Do you have any other questions related to this?

[joostmeijles]

Can you please elaborate to what extent there is support?

Is there for example only support for the unstable_revalidate (https://github.com/cassidoo/sonnet-18/blob/f3f21bcb3b27bbfbdcac73c8798eb4c951ded06a/pages/compare/%5B...slug%5D.js#L48)?

In my test revalidate: 1 did not generate a serverless function.

[joostmeijles]

I created netlify/next-on-netlify#37 to explore the option of adding incremental static regeneration.

[FinnWoelm]

Hey @joostmeijles,

You are right — there is currently no support for incremental static regeneration (ISR).

Ideally, pages with ISR should be statically pre-rendered and then re-rendered upon request at the provided revalidation interval. This is currently not possible, because we can only either have a static page or have a page that is server-side rendered. Netlify is investigating and researching possibilities for fully supporting ISR.

In the meantime, your proposal to server-side render pages with ISR is a fantastic workaround. This means that these pages will be less performant than regular static pages, but at least their content will be fresh. I believe that a focus on the freshness of the content does indeed match the intention of the user more closely than a focus on the page's performance.

Based on your excellent work done in netlify/next-on-netlify#37, I created a WIP branch to server-side render pages with incremental static regeneration: incremental-static-regeneration. It looks like it's working well — but I would like to refactor some code before I merge it into master. So it may be another week before it ships.

Again, thank you for raising this issue and for your very helpful proposal! 😊
- Finn

[cassidoo]

Thanks so much for this work @joostmeijles and @FinnWoelm! This is so exciting to get even more support for ISR. Are there any other gaps that need to be filled to get this better supported?

[joostmeijles]

@cassidoo I think Netlify stale-while-revalidate support is needed to fully support ISR.

[joostmeijles]

It seems that ISR somehow stopped working on the Netlify CDN.

The serverless (SSR) functions complete but do not return and therefore result in a timeout after 10 seconds.

For example:

{"errorMessage":"2020-10-21T14:05:48.488Z 604afa24-2c41-46d8-840e-a925c1e03587 Task timed out after 10.01 seconds"}

@FinnWoelm @cassidoo any clues ?

[FinnWoelm]

@joostmeijles things are still working on my end! The last release is 20 days old, so there shouldn't have been any change sincethen.

Is it possible that you use some sort of third party library that keeps a connection open? Last week, @garrypolley reported something like this when using Prisma: netlify/next-on-netlify#55 (comment)

Otherwise, happy to have a look at your code and/or see if we can reproduce this issue somewhere.

[joostmeijles]

Is it possible that you use some sort of third party library that keeps a connection open?

Possibly! Will dig a bit deeper 🙂

[FinnWoelm]

Okay, sounds good! Quick test would be to add a super simple page without any imports and seeing if that works.

Something along the lines of this:

// pages/mypage.js

export default function MyPage() {
  return (
    <p>Hello World</p>
  );
}

export function getStaticProps() {
  return {
    props: {},
    revalidate: 1
  };
}

[davetayls]

I am trying to get this working for a project and am finding that the pages are always hitting the function and are not being cached at the CDN. Is that the behaviour you are finding?

[joostmeijles]

That’s the expected behavior. It currently basically works the same as SSR pages. Op do 3 dec. 2020 om 13:06 schreef Dave Taylor <notifications@github.com>

…

I am trying to get this working for a project and am finding that the pages are always hitting the function and are not being cached at the CDN. Is that the behaviour you are finding? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <https://github.com/netlify/next-on-netlify/issues/35#issuecomment-737900953>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABBEECRB3SKGKC6VBPQ546TSS55MLANCNFSM4QQSDNRA> .