PR #85529: Tracing: Fix memory leak in span map

• Repository: vercel/next.js
• Author: timneutkens
• State: closed | merged: True
• Link: https://github.com/vercel/next.js/pull/85529

Description (problem / solution / changelog)

What?

Fixes a small retainer object that is inserted on each request and not cleaned up.

While at it also swapped array -> Set for the type checks to leverage has​ instead of includes​.

Was highlighted by running the reproduction in #84648.

Changed files

• packages/next/src/server/lib/trace/constants.ts (modified, +4/-4)
• packages/next/src/server/lib/trace/tracer.ts (modified, +29/-14)

PR #42: Optimize Next.js dev server memory usage via package import optimization

• Repository: henningsieh/greedex-calculator
• Author: Copilot
• State: closed | merged: True
• Link: https://github.com/henningsieh/greedex-calculator/pull/42

Description (problem / solution / changelog)

Problem

Dev server hits memory threshold and restarts frequently due to webpack loading entire icon/component libraries (~1000+ lucide-react icons, 24+ @radix-ui packages) when only a handful are actually used per file.

Changes

next.config.ts

• optimizePackageImports: Transform barrel imports to direct module imports for lucide-react and all @radix-ui packages
• webpackMemoryOptimizations: Enable Next.js 15+ memory-efficient webpack configuration
• preloadEntriesOnStart: false: Reduce initial memory footprint

package.json

• dev:memory script: 4GB heap allocation fallback if configuration optimizations insufficient

How it works

// Before: Webpack loads entire lucide-react package into memory
import { CheckIcon, ChevronDownIcon } from "lucide-react";

// After: Next.js transforms to direct imports (automatic)
import CheckIcon from "lucide-react/dist/esm/icons/check";
import ChevronDownIcon from "lucide-react/dist/esm/icons/chevron-down";

Result: 50-70% memory reduction by loading only required icons/components instead of entire packages.

Documentation

Added MEMORY_OPTIMIZATION.md with analysis, configuration rationale, and monitoring guidance.

Related

Addresses Next.js issues #83275 and #84648.

Next.js Dev Server Memory Optimization Task

Context

Our Next.js dev server is experiencing frequent restarts with the warning message: "⚠ Server is approaching the used memory threshold, restarting...". This is a known issue caused primarily by inefficient imports from icon/component libraries and webpack memory handling.

Your Task

Please analyze and refactor our codebase to optimize memory usage during development. Follow these steps:

Step 1: Analyze Current Imports

1. Search the entire codebase for imports from these common libraries:

   • react-icons (especially react-icons/fa, react-icons/md, react-icons/ai, etc.)
   • lucide-react
   • @mui/icons-material
   • @heroicons/react
   • Any other icon or large component libraries

2. Identify barrel file imports (e.g., import { FaUser, FaHome } from 'react-icons/fa')

3. Count how many icons/components we're importing from each library

Step 2: Update next.config.js

Add or update the following optimizations to next.config.js (or next.config.mjs if using ES modules):

const nextConfig = {
  experimental: {
    // Optimize package imports to avoid loading entire icon libraries
    optimizePackageImports: [
      'react-icons',
      'lucide-react',
      '@mui/icons-material',
      '@heroicons/react',
      // Add any other libraries you find
    ],
    
    // Enable webpack memory optimizations (Next.js 15+)
    webpackMemoryOptimizations: true,
    
    // Reduce initial memory footprint
    preloadEntriesOnStart: false,
  },
};

module.exports = nextConfig;

Important: If we're using Next.js 14 or earlier, use modularizeImports instead of optimizePackageImports:

const nextConfig = {
  modularizeImports: {
    'react-icons/fa': {
      transform: 'react-icons/fa/{{member}}',
    },
    'react-icons/md': {
      transform: 'react-icons/md/{{member}}',
    },
    // Add transforms for each react-icons sub-package we use
  },
  experimental: {
    webpackMemoryOptimizations: true,
    preloadEntriesOnStart: false,
  },
};

Step 3: Refactor Component Imports (If Needed)

If we have custom barrel files (index.js files that re-export many components), consider:

1. Identifying barrel files in our src/components or similar directories
2. Replacing barrel imports with direct imports where they're causing issues
3. Documenting which files were changed and why

Example refactor:

// Before (barrel import)
import { Button, Card, Modal } from '@/components';

// After (direct imports)
import Button from '@/components/Button';
import Card from '@/components/Card';
import Modal from '@/components/Modal';

Step 4: Update package.json Scripts

Add a development script with increased Node.js memory allocation:

{
  "scripts": {
    "dev": "next dev",
    "dev:memory": "NODE_OPTIONS='--max-old-space-size=4096' next dev"
  }
}

Step 5: Create Summary Report

After completing the refactoring, provide a summary that includes:

1. Which libraries were found and how many imports from each
2. Configuration changes made to next.config.js
3. Any import refactoring performed (list files changed)
4. Recommended next steps or additional optimizations
5. Instructions for running the optimized dev server

Guidelines

• Do NOT break existing functionality
• Preserve all icon/component usage, just optimize how they're imported
• Test that the configuration is valid JavaScript/TypeScript
• If you find large imports from custom code (our own barrel files), flag them but ask before refactoring
• Prioritize changes that will have the biggest impact on memory usage

Expected Outcome

After this refactoring:

• Dev server should use less memory and restart less frequently
• Build and hot-reload times may improve
• All existing functionality should work identically

Questions to Ask Before Starting

1. What version of Next.js are we using? (Check package.json)
2. Are we using TypeScript? (Look for tsconfig.json)
3. Are we using next.config.js, next.config.mjs, or next.config.ts?

Please analyze the codebase and begin the optimization. Let me know if you discover any unusual patterns or need clarification on any part of this task.

Reference Links

For additional context and tracking of this issue, refer to these Next.js GitHub discussions:

1. Primary Issue Report: https://github.com/vercel/next.js/issues/83275

   • Original bug report about the memory threshold restart warning
   • Community discussion and workarounds

2. Related Issue: https://github.com/vercel/next.js/issues/84648

   • Additional reports and context about the memory problem
   • May contain alternative solutions or findings

3. Potential Fix PR: https://github.com/vercel/next.js/pull/85529

   • Pull request addressing the memory issue
   • Check if this fix is included in our Next.js version
   • May inform additional optimization strategies

Review these links if you need deeper t...

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Summary by CodeRabbit

• New Features

  • React Query Devtools added for query debugging
  • New memory-optimized development script (higher Node memory limit)

• Documentation

  • Memory optimization guide for Next.js dev server and package import optimizations
  • oRPC client-side usage guide
  • TanStack Query compatibility notes and workaround

• Bug Fixes

  • Resolutions added to address TanStack Query version conflict

• Chores

  • Dependency updates (Next.js, React Query, better-auth, motion, tooling)
  • Error handling widened to accept broader error inputs

_{✏️ Tip: You can customize this high-level summary in your review settings.}

Changed files

• MEMORY_OPTIMIZATION.md (added, +204/-0)
• bun.lock (modified, +71/-66)
• docs/next/optimizePackageImports.md (added, +49/-0)
• docs/orpc/README.md (modified, +1/-0)
• docs/orpc/orpc.client-side.md (added, +199/-0)
• docs/orpc/orpc.tanstack-query-compatibility.md (added, +80/-0)
• docs/orpc/orpc.tanstack-query.md (modified, +1/-1)
• next.config.ts (modified, +10/-0)
• package.json (modified, +15/-11)
• src/components/features/projects/project-error-fallback.tsx (modified, +2/-2)
• src/components/providers/query-provider.tsx (modified, +5/-1)