[Bug]: deadlock in worker cleanup leads to zombie workers #493

Open
Open
[Bug]: deadlock in worker cleanup leads to zombie workers#493
Labels
bugSomething isn't workingtriage

Description

@parkan
parkan
opened on May 21, 2025

Description

still investigating this but we are observing thousands of deadlocks in worker cleanup calls:

 blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

Steps to Reproduce

appears to happen when a larger number of workers is enabled, especially across multiple parent processes

Version

tbd

Operating System

Linux

Database Backend

PostgreSQL

Additional context

No response

Metadata

Metadata

Assignees

No one assigned

    Labels

    bugSomething isn't workingtriage

    Type

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      , 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
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} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

      Skip to content
      [Bug]: deadlock in worker cleanup leads to zombie workers #493
      Open
      Open
      [Bug]: deadlock in worker cleanup leads to zombie workers#493
      Labels
      bugSomething isn't workingtriage
      Description
      @parkan
      parkan
      opened on May 21, 2025
      Description
      still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
       blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

      Steps to Reproduce
      appears to happen when a larger number of workers is enabled, especially across multiple parent processes
      Version
      tbd
      Operating System
      Linux
      Database Backend
      PostgreSQL
      Additional context
      No response
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        bugSomething isn't workingtriage
        Type
        No type
        Projects
        No projects
          Milestone
          No milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
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style.textContent = '
.markdown-body {
color-scheme: dark light;
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})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

          Skip to content
          [Bug]: deadlock in worker cleanup leads to zombie workers #493
          Open
          Open
          [Bug]: deadlock in worker cleanup leads to zombie workers#493
          Labels
          bugSomething isn't workingtriage
          Description
          @parkan
          parkan
          opened on May 21, 2025
          Description
          still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
           blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

          Steps to Reproduce
          appears to happen when a larger number of workers is enabled, especially across multiple parent processes
          Version
          tbd
          Operating System
          Linux
          Database Backend
          PostgreSQL
          Additional context
          No response
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            bugSomething isn't workingtriage
            Type
            No type
            Projects
            No projects
              Milestone
              No milestone
              Relationships
              None yet
              Development
              No branches or pull requests
              Issue actions
              
, 'i');
if (__m === '*' || __re.test(location.href)) {
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observer.observe(document.body, { childList: true, subtree: true });
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} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              [Bug]: deadlock in worker cleanup leads to zombie workers #493
              Open
              Open
              [Bug]: deadlock in worker cleanup leads to zombie workers#493
              Labels
              bugSomething isn't workingtriage
              Description
              @parkan
              parkan
              opened on May 21, 2025
              Description
              still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
               blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

              Steps to Reproduce
              appears to happen when a larger number of workers is enabled, especially across multiple parent processes
              Version
              tbd
              Operating System
              Linux
              Database Backend
              PostgreSQL
              Additional context
              No response
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                bugSomething isn't workingtriage
                Type
                No type
                Projects
                No projects
                  Milestone
                  No milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions
                  
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Strip utm_, fbclid, gclid, etc. from all links on page
(function() {
var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',
'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',
'ref', 'ref_src', 'source', 'medium', 'campaign'];
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try {
var u = new URL(url, window.location.origin);
var changed = false;
trackingParams.forEach(function(p) {
if (u.searchParams.has(p)) {
u.searchParams.delete(p);
changed = true;
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})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

                  Skip to content
                  [Bug]: deadlock in worker cleanup leads to zombie workers #493
                  Open
                  Open
                  [Bug]: deadlock in worker cleanup leads to zombie workers#493
                  Labels
                  bugSomething isn't workingtriage
                  Description
                  @parkan
                  parkan
                  opened on May 21, 2025
                  Description
                  still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
                   blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

                  Steps to Reproduce
                  appears to happen when a larger number of workers is enabled, especially across multiple parent processes
                  Version
                  tbd
                  Operating System
                  Linux
                  Database Backend
                  PostgreSQL
                  Additional context
                  No response
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    bugSomething isn't workingtriage
                    Type
                    No type
                    Projects
                    No projects
                      Milestone
                      No milestone
                      Relationships
                      None yet
                      Development
                      No branches or pull requests
                      Issue actions
                      
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Auto-enable theater mode on YouTube
(function() {
function tryTheater() {
var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]');
if (btn && !btn.classList.contains('activated')) {
btn.click();
}
}
// Try immediately
tryTheater();
// Try after navigation (SPA)
var lastUrl = location.href;
setInterval(function() {
if (location.href !== lastUrl) {
lastUrl = location.href;
setTimeout(tryTheater, 500);
}
}, 1000);
// Also try on player load
var observer = new MutationObserver(tryTheater);
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                      Skip to content
                      [Bug]: deadlock in worker cleanup leads to zombie workers #493
                      Open
                      Open
                      [Bug]: deadlock in worker cleanup leads to zombie workers#493
                      Labels
                      bugSomething isn't workingtriage
                      Description
                      @parkan
                      parkan
                      opened on May 21, 2025
                      Description
                      still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
                       blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

                      Steps to Reproduce
                      appears to happen when a larger number of workers is enabled, especially across multiple parent processes
                      Version
                      tbd
                      Operating System
                      Linux
                      Database Backend
                      PostgreSQL
                      Additional context
                      No response
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        bugSomething isn't workingtriage
                        Type
                        No type
                        Projects
                        No projects
                          Milestone
                          No milestone
                          Relationships
                          None yet
                          Development
                          No branches or pull requests
                          Issue actions
                          
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Remove or un-stick sticky/fixed headers that block content
(function() {
function unstick() {
document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) {
if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {
el.style.position = 'static';
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observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
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} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

                          Skip to content
                          [Bug]: deadlock in worker cleanup leads to zombie workers #493
                          Open
                          Open
                          [Bug]: deadlock in worker cleanup leads to zombie workers#493
                          Labels
                          bugSomething isn't workingtriage
                          Description
                          @parkan
                          parkan
                          opened on May 21, 2025
                          Description
                          still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
                           blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

                          Steps to Reproduce
                          appears to happen when a larger number of workers is enabled, especially across multiple parent processes
                          Version
                          tbd
                          Operating System
                          Linux
                          Database Backend
                          PostgreSQL
                          Additional context
                          No response
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            bugSomething isn't workingtriage
                            Type
                            No type
                            Projects
                            No projects
                              Milestone
                              No milestone
                              Relationships
                              None yet
                              Development
                              No branches or pull requests
                              Issue actions
                              
, 'i');
if (__m === '*' || __re.test(location.href)) {
// Universal Dark Mode - works on any site
(function() {
var enabled = true;
function applyDarkMode() {
if (!enabled) return;
// Create style element if it doesn't exist
var style = document.getElementById('universal-dark-mode-style');
if (!style) {
style = document.createElement('style');
style.id = 'universal-dark-mode-style';
document.head.appendChild(style);
}
// Dark mode CSS - inverts colors but preserves images/video
style.textContent = '
/* Invert everything except media */
html {
filter: invert(1) hue-rotate(180deg) !important;
background: #1a1a2e !important;
}
/* Restore images, videos, iframes, canvas */
img, video, iframe, canvas, svg, picture, [style*="background-image"] {
filter: invert(1) hue-rotate(180deg) !important;
}
/* Preserve specific elements that should not be inverted */
.no-dark-mode, .no-dark-mode *,
[data-theme="light"], [data-theme="light"],
.ace_editor, .ace_editor *,
.CodeMirror, .CodeMirror *,
.monaco-editor, .monaco-editor *,
.markdown-body pre, .markdown-body pre *,
.highlight, .highlight *,
pre code, pre code * {
filter: none !important;
}
/* Fix common UI elements */
.modal, .popup, .dropdown-menu, .tooltip, .popover {
filter: invert(1) hue-rotate(180deg) !important;
background: #2d2d44 !important;
border-color: #444 !important;
}
/* Scrollbars */
::-webkit-scrollbar { background: #1a1a2e !important; }
::-webkit-scrollbar-thumb { background: #444 !important; }
::-webkit-scrollbar-thumb:hover { background: #555 !important; }
/* Selection */
::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }
';
}
function removeDarkMode() {
var style = document.getElementById('universal-dark-mode-style');
if (style) style.remove();
}
// Toggle with Alt+Shift+D
document.addEventListener('keydown', function(e) {
if (e.altKey && e.shiftKey && e.key === 'D') {
e.preventDefault();
enabled = !enabled;
if (enabled) {
applyDarkMode();
console.log('[Universal Dark Mode] Enabled');
} else {
removeDarkMode();
console.log('[Universal Dark Mode] Disabled');
}
}
});
// Apply on load
applyDarkMode();
// Re-apply on dynamic content
var observer = new MutationObserver(function(mutations) {
if (enabled && !document.getElementById('universal-dark-mode-style')) {
applyDarkMode();
}
});
observer.observe(document.head, { childList: true });
console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');
})();
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

                              Skip to content
                              [Bug]: deadlock in worker cleanup leads to zombie workers #493
                              Open
                              Open
                              [Bug]: deadlock in worker cleanup leads to zombie workers#493
                              Labels
                              bugSomething isn't workingtriage
                              Description
                              @parkan
                              parkan
                              opened on May 21, 2025
                              Description
                              still investigating this but we are observing thousands of deadlocks in worker cleanup calls:
                               blocked_pid | blocking_pid | blocked_user | blocking_user | blocking_duration | blocked_query | blocking_query -------------+--------------+--------------+---------------+-------------------------+-------------------------------------------------------------------+------------------
-----------------------------------------
193590 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
184265 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
216642 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
187480 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1
191185 | 190674 | singularity | singularity | 3 days 13:38:47.888695 | DELETE FROM "workers" WHERE last_heartbeat < $1 | DELETE FROM "work
ers" WHERE last_heartbeat < $1

                              Steps to Reproduce
                              appears to happen when a larger number of workers is enabled, especially across multiple parent processes
                              Version
                              tbd
                              Operating System
                              Linux
                              Database Backend
                              PostgreSQL
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                              No response
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