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Gracefully shutdown is hang while a SSE connection is established #493

Closed
#494
Closed
Gracefully shutdown is hang while a SSE connection is established#493
#494

Description

@greenhat616
greenhat616
opened on Oct 21, 2025

Describe the bug
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.

To Reproduce

  1. start the server
RUST_LOG=trace cargo run --example servers_counter_streamhtt

  1. create a client connection to server via @modelcontextprotocol/inspector

  2. press CTRL + C to trigger server exits

Image

I noted the sse transport has similar issue, but I don't dig it deep.

Expected behavior
While trigger cancelled, the server will exits immediately.

Logs
If applicable, add logs to help explain your problem.

Additional context
Add any other context about the problem here.

Metadata

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      , 'i'); if (__m === '*' || __re.test(location.href)) { // Add copy buttons to all 
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function addCopyButtons() {
document.querySelectorAll('pre code').forEach(function(codeBlock) {
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btn.onmouseover = function() { this.style.opacity = '1'; };
btn.onmouseout = function() { this.style.opacity = '0.7'; };
btn.onclick = function() {
navigator.clipboard.writeText(codeBlock.textContent).then(function() {
btn.textContent = 'Copied!';
setTimeout(function() { btn.textContent = 'Copy'; }, 1500);
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codeBlock.parentElement.style.position = 'relative';
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observer.observe(document.body, { childList: true, subtree: true });
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} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
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(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
      Skip to content
      Gracefully shutdown is hang while a SSE connection is established #493
      Closed
      #494
      Closed
      Gracefully shutdown is hang while a SSE connection is established#493
      #494
      Description
      @greenhat616
      greenhat616
      opened on Oct 21, 2025
      Describe the bug
      
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
      To Reproduce
      1. start the server
      RUST_LOG=trace cargo run --example servers_counter_streamhtt
      1. create a client connection to server via @modelcontextprotocol/inspector
      2. press CTRL + C to trigger server exits
      Image
      I noted the sse transport has similar issue, but I don't dig it deep.
      Expected behavior
      
While trigger cancelled, the server will exits immediately.
      Logs
      
If applicable, add logs to help explain your problem.
      Additional context
      
Add any other context about the problem here.
      Metadata
      Metadata
      Assignees
      No one assigned
        Labels
        No labels
        No labels
        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)) {
// Force GitHub README to respect dark mode
(function() {
var style = document.createElement('style');
style.textContent = '
.markdown-body {
color-scheme: dark light;
}
.markdown-body pre { background: #161b22 !important; }
.markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }
.markdown-body table th, .markdown-body table td { border-color: #30363d !important; }
.markdown-body img { background: #0d1117; }
.markdown-body blockquote { border-left-color: #8b949e; }
.markdown-body hr { border-color: #30363d; }
';
document.head.appendChild(style);
})();
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
          Skip to content
          Gracefully shutdown is hang while a SSE connection is established #493
          Closed
          #494
          Closed
          Gracefully shutdown is hang while a SSE connection is established#493
          #494
          Description
          @greenhat616
          greenhat616
          opened on Oct 21, 2025
          Describe the bug
          
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
          To Reproduce
          1. start the server
          RUST_LOG=trace cargo run --example servers_counter_streamhtt
          1. create a client connection to server via @modelcontextprotocol/inspector
          2. press CTRL + C to trigger server exits
          Image
          I noted the sse transport has similar issue, but I don't dig it deep.
          Expected behavior
          
While trigger cancelled, the server will exits immediately.
          Logs
          
If applicable, add logs to help explain your problem.
          Additional context
          
Add any other context about the problem here.
          Metadata
          Metadata
          Assignees
          No one assigned
            Labels
            No labels
            No labels
            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)) {
// Highlight search terms from Google/DuckDuckGo/Bing referrer
(function() {
var ref = document.referrer;
var terms = [];
if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {
var url = new URL(ref);
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if (q) {
terms = q.split(/\s+/).filter(function(t) { return t.length > 2; });
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if (terms.length === 0) return;
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style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';
document.head.appendChild(style);
function highlight(node) {
if (node.nodeType === 3) { // text node
var text = node.textContent;
var found = false;
terms.forEach(function(term) {
var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\]\\]/g, '\\') + ')', 'gi');
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found = true;
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parts.forEach(function(part, i) {
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frag.appendChild(document.createTextNode(part));
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var span = document.createElement('span');
span.className = 'userscript-highlight';
span.textContent = part;
frag.appendChild(span);
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node.parentNode.replaceChild(frag, node);
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var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];
if (!skipTags.includes(node.tagName)) {
Array.from(node.childNodes).forEach(highlight);
}
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}
highlight(document.body);
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var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1 || node.nodeType === 3) highlight(node);
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
              Skip to content
              Gracefully shutdown is hang while a SSE connection is established #493
              Closed
              #494
              Closed
              Gracefully shutdown is hang while a SSE connection is established#493
              #494
              Description
              @greenhat616
              greenhat616
              opened on Oct 21, 2025
              Describe the bug
              
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
              To Reproduce
              1. start the server
              RUST_LOG=trace cargo run --example servers_counter_streamhtt
              1. create a client connection to server via @modelcontextprotocol/inspector
              2. press CTRL + C to trigger server exits
              Image
              I noted the sse transport has similar issue, but I don't dig it deep.
              Expected behavior
              
While trigger cancelled, the server will exits immediately.
              Logs
              
If applicable, add logs to help explain your problem.
              Additional context
              
Add any other context about the problem here.
              Metadata
              Metadata
              Assignees
              No one assigned
                Labels
                No labels
                No labels
                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'];
function cleanUrl(url) {
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;
}
});
return changed ? u.toString() : url;
} catch (e) {
return url;
}
}
function cleanLinks() {
document.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
cleanLinks();
var observer = new MutationObserver(function(mutations) {
mutations.forEach(function(m) {
m.addedNodes.forEach(function(node) {
if (node.nodeType === 1) {
if (node.tagName === 'A') cleanLinks();
node.querySelectorAll('a[href]').forEach(function(a) {
var clean = cleanUrl(a.href);
if (clean !== a.href) a.href = clean;
});
}
});
});
});
observer.observe(document.body, { childList: true, subtree: true });
})();
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
                  Skip to content
                  Gracefully shutdown is hang while a SSE connection is established #493
                  Closed
                  #494
                  Closed
                  Gracefully shutdown is hang while a SSE connection is established#493
                  #494
                  Description
                  @greenhat616
                  greenhat616
                  opened on Oct 21, 2025
                  Describe the bug
                  
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
                  To Reproduce
                  1. start the server
                  RUST_LOG=trace cargo run --example servers_counter_streamhtt
                  1. create a client connection to server via @modelcontextprotocol/inspector
                  2. press CTRL + C to trigger server exits
                  Image
                  I noted the sse transport has similar issue, but I don't dig it deep.
                  Expected behavior
                  
While trigger cancelled, the server will exits immediately.
                  Logs
                  
If applicable, add logs to help explain your problem.
                  Additional context
                  
Add any other context about the problem here.
                  Metadata
                  Metadata
                  Assignees
                  No one assigned
                    Labels
                    No labels
                    No labels
                    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('^' + ".*" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
                      Skip to content
                      Gracefully shutdown is hang while a SSE connection is established #493
                      Closed
                      #494
                      Closed
                      Gracefully shutdown is hang while a SSE connection is established#493
                      #494
                      Description
                      @greenhat616
                      greenhat616
                      opened on Oct 21, 2025
                      Describe the bug
                      
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
                      To Reproduce
                      1. start the server
                      RUST_LOG=trace cargo run --example servers_counter_streamhtt
                      1. create a client connection to server via @modelcontextprotocol/inspector
                      2. press CTRL + C to trigger server exits
                      Image
                      I noted the sse transport has similar issue, but I don't dig it deep.
                      Expected behavior
                      
While trigger cancelled, the server will exits immediately.
                      Logs
                      
If applicable, add logs to help explain your problem.
                      Additional context
                      
Add any other context about the problem here.
                      Metadata
                      Metadata
                      Assignees
                      No one assigned
                        Labels
                        No labels
                        No labels
                        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';
el.style.top = 'auto';
el.style.zIndex = 'auto';
}
});
}
unstick();
var observer = new MutationObserver(unstick);
observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
})();
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
                          Skip to content
                          Gracefully shutdown is hang while a SSE connection is established #493
                          Closed
                          #494
                          Closed
                          Gracefully shutdown is hang while a SSE connection is established#493
                          #494
                          Description
                          @greenhat616
                          greenhat616
                          opened on Oct 21, 2025
                          Describe the bug
                          
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
                          To Reproduce
                          1. start the server
                          RUST_LOG=trace cargo run --example servers_counter_streamhtt
                          1. create a client connection to server via @modelcontextprotocol/inspector
                          2. press CTRL + C to trigger server exits
                          Image
                          I noted the sse transport has similar issue, but I don't dig it deep.
                          Expected behavior
                          
While trigger cancelled, the server will exits immediately.
                          Logs
                          
If applicable, add logs to help explain your problem.
                          Additional context
                          
Add any other context about the problem here.
                          Metadata
                          Metadata
                          Assignees
                          No one assigned
                            Labels
                            No labels
                            No labels
                            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); }
})();
})();
Gracefully shutdown is hang while a SSE connection is established · Issue #493 · modelcontextprotocol/rust-sdk · GitHub
                              Skip to content
                              Gracefully shutdown is hang while a SSE connection is established #493
                              Closed
                              #494
                              Closed
                              Gracefully shutdown is hang while a SSE connection is established#493
                              #494
                              Description
                              @greenhat616
                              greenhat616
                              opened on Oct 21, 2025
                              Describe the bug
                              
While using streamable-http transport. The SseBody donnot handle the signal of gracefully shutdown, thus, blocking the shutdown process until client disconnect.
                              To Reproduce
                              1. start the server
                              RUST_LOG=trace cargo run --example servers_counter_streamhtt
                              1. create a client connection to server via @modelcontextprotocol/inspector
                              2. press CTRL + C to trigger server exits
                              Image
                              I noted the sse transport has similar issue, but I don't dig it deep.
                              Expected behavior
                              
While trigger cancelled, the server will exits immediately.
                              Logs
                              
If applicable, add logs to help explain your problem.
                              Additional context
                              
Add any other context about the problem here.
                              Metadata
                              Metadata
                              Assignees
                              No one assigned
                                Labels
                                No labels
                                No labels
                                Type
                                No type
                                Projects
                                No projects
                                  Milestone
                                  No milestone
                                  Relationships
                                  None yet
                                  Development
                                  No branches or pull requests
                                  Issue actions