Stop launching extra Comfy Pythons when the running instance is just busy.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/comfy-host-agent.mjs

@@ -677,10 +677,27 @@ const server = http.createServer(async (req, res) => {
       markWork()
       return json(res, 200, { ok: true, started: false, already: true, asleep: false, port: healthyPort, proxyPort })
     }
-    if (lastLaunchAt && Date.now() - lastLaunchAt < 60_000) {
+    const listenPort = desktopListenPort()
+    const processAlive = lastProcessUp || await processUp().catch(() => false) || await pythonMainUp().catch(() => false)
+    const portBusy = await portInUse(listenPort)
+    const recentlySlow = [...probeSkipUntil.entries()].some(([, until]) => Date.now() < until)
+    if (processAlive || portBusy || recentlySlow) {
+      markWork()
+      lastProcessUp = true
+      if (portBusy) setProxyTarget(listenPort)
+      return json(res, 200, {
+        ok: true,
+        started: false,
+        already: true,
+        booting: true,
+        asleep: false,
+        port: portBusy ? listenPort : null,
+        proxyPort
+      })
+    }
+    if (lastLaunchAt && Date.now() - lastLaunchAt < 5 * 60_000) {
       return json(res, 200, { ok: true, started: false, already: true, booting: true, asleep: false, proxyPort })
     }
-    await taskkillImage('Comfy Desktop.exe')
     stoppedByAgent = false
     lastLaunchAt = Date.now()
     const launched = await startComfy()

server/utils/comfyLifecycle.ts

@@ -52,15 +52,16 @@ export async function checkComfyHttp(timeoutMs = 5000, host?: string) {
   let resolved = host || ''
   try {
     if (!resolved) {
-      if (!comfyConfigured()) return { ok: false as const, host: '', status: 0, stats: null }
+      if (!comfyConfigured()) return { ok: false as const, host: '', status: 0, stats: null, timedOut: false }
       resolved = getComfyHost()
     }
     const res = await fetch(`${resolved}/system_stats`, { signal: AbortSignal.timeout(timeoutMs) })
-    if (!res.ok) return { ok: false as const, host: resolved, status: res.status, stats: null }
+    if (!res.ok) return { ok: false as const, host: resolved, status: res.status, stats: null, timedOut: false }
     const stats = await res.json().catch(() => null)
-    return { ok: true as const, host: resolved, status: res.status, stats }
+    return { ok: true as const, host: resolved, status: res.status, stats, timedOut: false }
-  } catch {
+  } catch (error) {
-    return { ok: false as const, host: resolved, status: 0, stats: null }
+    const timedOut = error instanceof Error && (error.name === 'TimeoutError' || error.name === 'AbortError' || /timeout/i.test(error.message))
+    return { ok: false as const, host: resolved, status: 0, stats: null, timedOut }
   }
 }
 
@@ -348,6 +349,24 @@ async function ensureUnlocked(onStatus: StatusFn, skipBusyWait = false) {
     onStatus({ state: 'online', message: 'ComfyUI online', host })
     return
   }
+  if (health.timedOut) {
+    log('http-busy', { host, timeoutMs: cfg.healthTimeoutMs })
+    const retry = await checkComfyHttp(Math.max(cfg.healthTimeoutMs, 12_000))
+    if (retry.ok) {
+      if (!skipBusyWait) await waitWhileBusy(onStatus)
+      onStatus({ state: 'online', message: 'ComfyUI online', host })
+      return
+    }
+    onStatus({
+      state: 'busy',
+      message: 'ComfyUI is loaded but slow to answer. Not starting another instance.',
+      host,
+      processRunning: true
+    })
+    if (!skipBusyWait) await waitWhileBusy(onStatus)
+    onStatus({ state: 'online', message: 'ComfyUI online', host, processRunning: true })
+    return
+  }
 
   log('http-fail', { host })
   const remote = await controlRequest('/status')
@@ -383,11 +402,9 @@ async function ensureUnlocked(onStatus: StatusFn, skipBusyWait = false) {
       onStatus({ state: 'online', message: 'ComfyUI online', host, processRunning: true })
       return
     }
-    onStatus({
+    throw createError({
-      state: 'starting',
+      statusCode: 503,
-      message: 'ComfyUI is running but the API never came up. Attempting a relaunch...',
+      statusMessage: 'ComfyUI is running but the API never came up. Not launching a second instance.'
-      host,
-      processRunning: true
     })
   }
 

server/utils/imageComfyLifecycle.ts

@@ -55,16 +55,17 @@ export async function checkImageComfyHttp(timeoutMs = 5000, host?: string) {
   let resolved = host || ''
   try {
     if (!resolved) {
-      if (!imageComfyConfigured()) return { ok: false as const, host: '', status: 0, stats: null }
+      if (!imageComfyConfigured()) return { ok: false as const, host: '', status: 0, stats: null, timedOut: false }
       resolved = getImageComfyHost()
     }
-    if (!resolved) return { ok: false as const, host: '', status: 0, stats: null }
+    if (!resolved) return { ok: false as const, host: '', status: 0, stats: null, timedOut: false }
     const res = await fetch(`${resolved}/system_stats`, { signal: AbortSignal.timeout(timeoutMs) })
-    if (!res.ok) return { ok: false as const, host: resolved, status: res.status, stats: null }
+    if (!res.ok) return { ok: false as const, host: resolved, status: res.status, stats: null, timedOut: false }
     const stats = await res.json().catch(() => null)
-    return { ok: true as const, host: resolved, status: res.status, stats }
+    return { ok: true as const, host: resolved, status: res.status, stats, timedOut: false }
-  } catch {
+  } catch (error) {
-    return { ok: false as const, host: resolved, status: 0, stats: null }
+    const timedOut = error instanceof Error && (error.name === 'TimeoutError' || error.name === 'AbortError' || /timeout/i.test(error.message))
+    return { ok: false as const, host: resolved, status: 0, stats: null, timedOut }
   }
 }
 
@@ -173,6 +174,18 @@ async function ensureUnlocked(onStatus: StatusFn) {
     onStatus({ state: 'online', message: 'Image ComfyUI online', host })
     return
   }
+  if (health.timedOut) {
+    log('http-busy', { host, timeoutMs: cfg.healthTimeoutMs })
+    onStatus({
+      state: 'busy',
+      message: 'Image ComfyUI is loaded but slow to answer. Not starting another instance.',
+      host,
+      processRunning: true
+    })
+    await waitWhileBusy(onStatus)
+    onStatus({ state: 'online', message: 'Image ComfyUI online', host, processRunning: true })
+    return
+  }
 
   const remote = await controlRequest('/status')
   if (remote?.http && remote.proxyPort) {