René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Not all processes rebind when switching from :: to 0.0.0.0 or vice versa","articleBody":"### Version\n\nv22.14.0\n\n### Platform\n\n```text\nDarwin YJF7M4-i4Xp 24.6.0 Darwin Kernel Version 24.6.0: Mon Jul 14 11:30:55 PDT 2025; root:xnu-11417.140.69~1/RELEASE_ARM64_T6031 arm64\n\nLinux b2dae3f0c05d 6.10.14-linuxkit #1 SMP Thu Mar 20 16:32:56 UTC 2025 aarch64 aarch64 aarch64 GNU/\n```\n\n### Subsystem\n\ncluster\n\n### What steps will reproduce the bug?\n\n1. Run program attached: `node listen-retry-issue.js `\n2. After all processes start (will take time), send `SIGTERM` to master process to initiate a rolling restart. \n\n    This will switch interfaces (initially from :: to 0.0.0.0 will toggle each time a SIGTERM is sent): `kill -SIGTERM \u003cmasterPid\u003e`\n\n3. After all workers restart (will take time) notice only a subset will successfully listen successfully\n\nFor example: if we have 10 processes and process 5 rebinds first: processes 5, 6, 7, 8, 9 will successfully rebind\nprocesses 0, 1, 2, 3, 4 will not rebind and will retry forever\n\nDepending on the platform tested with may need to send 2 SIGTERMS to trigger the `EADDRINUSE` scenario.\n\nAlso note that not using the `ipv6Only` listen option as our application must support dual stack when binding to ipv6 addresses.\n\n[listen-retry-issue.js](https://github.com/user-attachments/files/22643581/listen-retry-issue.js)\n\n### How often does it reproduce? Is there a required condition?\n\nUsing the program above it seems to reproduce most of the time. The only scenario that would cause the issue to not surface is if process 0 is the first to listen successfully. \n\nThe required condition is:\n\n1. Multiple processes bound to all interfaces with dual stack (::)\n2. Processes will retry listen when `EADDRINUSE` error occurs\n3. Switch interface from `:: to 0.0.0.0` (or vice versa) \n4. Perform a rolling restart (2 processes at a time) so some processes are still bound to the old interface and port during restart.\n5. After all processes restart, the problem should surface.\n6. Only a subset of workers will successfully bind to the new interface and port\n\n### What is the expected behavior? Why is that the expected behavior?\n\nExpected behavior is that all workers successfully rebind to the interface and port, not a subset.\n\n### What do you see instead?\n\nA subset of workers processes are successfully rebinding and there is a strange pattern that dictates which workers rebind. For example:\n\nWith 10 processes are restarted and worker 6 is the first to bind, workers 6, 7, 8, and 9 will successfully rebind to the interface and port. Workers 0, 1, 2, 3, 4, and 5 will fail to rebind and be in a forever retry loop.\n\n### Additional information\n\nHere is annotated log output from the attached program demonstrating the problem.\n\n**Scenario**\n- 12 processes\n- Process 6 listens first, end up with:\n  - processes 6, 7, 8, 9, 10, 11 successfully listening\n  - processes 0, 1, 2, 3, 4, 5 in a retry forever loop\n  - Expecting all processes successfully rebind\n\n...\n#\n# The final 2 processes are restarted here\n#\nMaster process 0 (25286) detected worker 10 (27562) died\nMaster process 0 (25286) detected worker 11 (27563) died\n#\n# Process 6 and 7 bind successfully\n#\nWorker process 6 (29061) listening on 0.0.0.0:8000\nWorker process 7 (29062) listening on 0.0.0.0:8000\nWorker process 11 (29207) detected address 0.0.0.0:8000 in use, retrying in 517 MS...\nWorker process 10 (29206) detected address 0.0.0.0:8000 in use, retrying in 526 MS...\nWorker process 9 (29131) detected address 0.0.0.0:8000 in use, retrying in 537 MS...\nWorker process 8 (29130) detected address 0.0.0.0:8000 in use, retrying in 573 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 572 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 580 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 548 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 549 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 528 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 567 MS...\nMaster process 0 (25286) rolling restart completed, 12 processes restarted\n#\n# Process 8 and 9 bind successfully\n#\nWorker process 8 (29130) listening on 0.0.0.0:8000\nWorker process 9 (29131) listening on 0.0.0.0:8000\nWorker process 11 (29207) detected address 0.0.0.0:8000 in use, retrying in 555 MS...\nWorker process 10 (29206) detected address 0.0.0.0:8000 in use, retrying in 554 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 574 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 556 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 570 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 519 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 535 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 559 MS...\n#\n# Process 10 and 11 bind successfully\n#\nWorker process 10 (29206) listening on 0.0.0.0:8000\nWorker process 11 (29207) listening on 0.0.0.0:8000\n#\n# Processes 0, 1, 2, 3, 4, 5 are in a retry forever loop\n#\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 523 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 580 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 531 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 566 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 550 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 574 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 514 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 512 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 570 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 573 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 575 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 563 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 567 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 538 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 540 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 529 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 563 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 528 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 549 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 577 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 577 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 557 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 515 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 544 MS...\nWorker process 5 (28984) detected address 0.0.0.0:8000 in use, retrying in 571 MS...\nWorker process 4 (28985) detected address 0.0.0.0:8000 in use, retrying in 542 MS...\nWorker process 3 (28898) detected address 0.0.0.0:8000 in use, retrying in 537 MS...\nWorker process 2 (28897) detected address 0.0.0.0:8000 in use, retrying in 548 MS...\nWorker process 0 (28821) detected address 0.0.0.0:8000 in use, retrying in 518 MS...\nWorker process 1 (28820) detected address 0.0.0.0:8000 in use, retrying in 569 MS...\n...","author":{"url":"https://github.com/hgardneriv","@type":"Person","name":"hgardneriv"},"datePublished":"2025-10-01T16:10:48.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":0},"url":"https://github.com/60086/node/issues/60086"}