Optimizing Astro Blog Fuwari Builds to Fix Vercel OOM Errors

1. getStaticPaths Passing Full Entry Objects#

This was the most critical issue. The original code:

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export async function getStaticPaths() {
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    const posts = await getSortedPosts();
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    return posts.map((entry) => ({
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        params: { slug: entry.id },
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        props: { entry },  // Passing full entry object!
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    }));
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}

This means the complete content of all 500 posts was stored in route props simultaneously.

2. Unlimited Concurrent Builds#

Astro by default parallelizes page builds as much as possible, causing memory spikes in memory-constrained environments.

3. HTML Compression Using Extra Memory#

While HTML compression reduces file size, it requires additional memory during builds. CDNs (like Cloudflare, Vercel) automatically use Brotli compression for transfer, making local compression unnecessary.

1. Core Optimization: Pass Only Necessary Data in getStaticPaths#

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export async function getStaticPaths() {
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    const posts = await getSortedPosts();
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    // Only pass necessary navigation data
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    return posts.map((entry) => ({
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        params: { slug: entry.id },
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        props: {
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            slug: entry.id,
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            prevSlug: entry.data.prevSlug,
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            prevTitle: entry.data.prevTitle,
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            nextSlug: entry.data.nextSlug,
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            nextTitle: entry.data.nextTitle,
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        },
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    }));
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}
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// Fetch full content on-demand during rendering
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const { slug, prevSlug, prevTitle, nextSlug, nextTitle } = Astro.props;
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const entry = await getEntry("posts", slug);
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const { Content } = await render(entry);

This optimization reduced memory usage during getStaticPaths by over 90%.

2. Increase Node.js Memory Limit#

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{
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  "scripts": {
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    "build": "NODE_OPTIONS='--max-old-space-size=7168' astro build"
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  }
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}

Node.js default heap memory limit is around 2-4GB. Explicitly setting it to 7GB fully utilizes Vercel’s 8GB RAM.

3. Limit Build Concurrency#

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export default defineConfig({
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    build: {
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        concurrency: 2,  // Limit concurrent builds
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    },
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});

Interestingly, testing showed concurrency: 2 is faster than unlimited:

• concurrency: 2: 2m 19s ✅
• Unlimited: 3m 45s ❌

Test method:

• First concurrency: 2
• Run build and time it
• Increase to 4, then 6, then 8
• Use the fastest setting
• Important note: Not more better！Case studies found that 4 CPUs is the best choice on a 12-core system. Too much concurrency causes resource contention, actually slowing things down.

4. Disable HTML Compression#

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export default defineConfig({
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    compressHTML: false,  // Let CDN handle compression
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});

CDNs use Brotli compression (more efficient than gzip), so local HTML compression benefits are negligible. Better to save that memory and time.

5. Upgrade Build Target#

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// astro.config.mjs - vite config
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vite: {
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    build: {
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        target: 'es2022',  // Reduce code transpilation
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    },
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}

6. Fix Expressive Code Duplicate Themes#

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// Before (bug)
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themes: [theme, theme],  // Duplicated
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// After
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themes: [theme],