chore(monitoring): remove SSE connection tracking and Bun.gc debug instrumentation (#3472)

Author: waleedlatif1

apps/sim/app/api/a2a/serve/[agentId]/route.ts

@@ -19,7 +19,6 @@ import { validateUrlWithDNS } from '@/lib/core/security/input-validation.server'
 import { SSE_HEADERS } from '@/lib/core/utils/sse'
 import { getBaseUrl } from '@/lib/core/utils/urls'
 import { markExecutionCancelled } from '@/lib/execution/cancellation'
-import { decrementSSEConnections, incrementSSEConnections } from '@/lib/monitoring/sse-connections'
 import { checkWorkspaceAccess } from '@/lib/workspaces/permissions/utils'
 import { getWorkspaceBilledAccountUserId } from '@/lib/workspaces/utils'
 import {
@@ -631,11 +630,9 @@ async function handleMessageStream(
   }
 
   const encoder = new TextEncoder()
-  let messageStreamDecremented = false
 
   const stream = new ReadableStream({
     async start(controller) {
-      incrementSSEConnections('a2a-message')
       const sendEvent = (event: string, data: unknown) => {
         try {
           const jsonRpcResponse = {
@@ -845,19 +842,10 @@ async function handleMessageStream(
         })
       } finally {
         await releaseLock(lockKey, lockValue)
-        if (!messageStreamDecremented) {
-          messageStreamDecremented = true
-          decrementSSEConnections('a2a-message')
-        }
         controller.close()
       }
     },
-    cancel() {
-      if (!messageStreamDecremented) {
-        messageStreamDecremented = true
-        decrementSSEConnections('a2a-message')
-      }
-    },
+    cancel() {},
   })
 
   return new NextResponse(stream, {
@@ -1042,22 +1030,16 @@ async function handleTaskResubscribe(
     { once: true }
   )
 
-  let sseDecremented = false
   const cleanup = () => {
     isCancelled = true
     if (pollTimeoutId) {
       clearTimeout(pollTimeoutId)
       pollTimeoutId = null
     }
-    if (!sseDecremented) {
-      sseDecremented = true
-      decrementSSEConnections('a2a-resubscribe')
-    }
   }
 
   const stream = new ReadableStream({
     async start(controller) {
-      incrementSSEConnections('a2a-resubscribe')
       const sendEvent = (event: string, data: unknown): boolean => {
         if (isCancelled || abortSignal.aborted) return false
         try {

apps/sim/app/api/mcp/events/route.ts

@@ -14,7 +14,6 @@ import { getSession } from '@/lib/auth'
 import { SSE_HEADERS } from '@/lib/core/utils/sse'
 import { mcpConnectionManager } from '@/lib/mcp/connection-manager'
 import { mcpPubSub } from '@/lib/mcp/pubsub'
-import { decrementSSEConnections, incrementSSEConnections } from '@/lib/monitoring/sse-connections'
 import { getUserEntityPermissions } from '@/lib/workspaces/permissions/utils'
 
 const logger = createLogger('McpEventsSSE')
@@ -50,14 +49,11 @@ export async function GET(request: NextRequest) {
     for (const unsub of unsubscribers) {
       unsub()
     }
-    decrementSSEConnections('mcp-events')
     logger.info(`SSE connection closed for workspace ${workspaceId}`)
   }
 
   const stream = new ReadableStream({
     start(controller) {
-      incrementSSEConnections('mcp-events')
-
       const send = (eventName: string, data: Record<string, unknown>) => {
         if (cleaned) return
         try {

apps/sim/app/api/wand/route.ts

@@ -10,7 +10,6 @@ import { checkAndBillOverageThreshold } from '@/lib/billing/threshold-billing'
 import { env } from '@/lib/core/config/env'
 import { getCostMultiplier, isBillingEnabled } from '@/lib/core/config/feature-flags'
 import { generateRequestId } from '@/lib/core/utils/request'
-import { decrementSSEConnections, incrementSSEConnections } from '@/lib/monitoring/sse-connections'
 import { enrichTableSchema } from '@/lib/table/llm/wand'
 import { verifyWorkspaceMembership } from '@/app/api/workflows/utils'
 import { extractResponseText, parseResponsesUsage } from '@/providers/openai/utils'
@@ -331,14 +330,10 @@ export async function POST(req: NextRequest) {
         const encoder = new TextEncoder()
         const decoder = new TextDecoder()
 
-        let wandStreamClosed = false
         const readable = new ReadableStream({
           async start(controller) {
-            incrementSSEConnections('wand')
             const reader = response.body?.getReader()
             if (!reader) {
-              wandStreamClosed = true
-              decrementSSEConnections('wand')
               controller.close()
               return
             }
@@ -483,18 +478,9 @@ export async function POST(req: NextRequest) {
               controller.close()
             } finally {
               reader.releaseLock()
-              if (!wandStreamClosed) {
-                wandStreamClosed = true
-                decrementSSEConnections('wand')
-              }
-            }
-          },
-          cancel() {
-            if (!wandStreamClosed) {
-              wandStreamClosed = true
-              decrementSSEConnections('wand')
             }
           },
+          cancel() {},
         })
 
         return new Response(readable, {

apps/sim/app/api/workflows/[id]/execute/route.ts

@@ -22,7 +22,6 @@ import { createExecutionEventWriter, setExecutionMeta } from '@/lib/execution/ev
 import { processInputFileFields } from '@/lib/execution/files'
 import { preprocessExecution } from '@/lib/execution/preprocessing'
 import { LoggingSession } from '@/lib/logs/execution/logging-session'
-import { decrementSSEConnections, incrementSSEConnections } from '@/lib/monitoring/sse-connections'
 import {
   cleanupExecutionBase64Cache,
   hydrateUserFilesWithBase64,
@@ -764,7 +763,6 @@ export async function POST(req: NextRequest, { params }: { params: Promise<{ id:
     const encoder = new TextEncoder()
     const timeoutController = createTimeoutAbortController(preprocessResult.executionTimeout?.sync)
     let isStreamClosed = false
-    let sseDecremented = false
 
     const eventWriter = createExecutionEventWriter(executionId)
     setExecutionMeta(executionId, {
@@ -775,7 +773,6 @@ export async function POST(req: NextRequest, { params }: { params: Promise<{ id:
 
     const stream = new ReadableStream<Uint8Array>({
       async start(controller) {
-        incrementSSEConnections('workflow-execute')
         let finalMetaStatus: 'complete' | 'error' | 'cancelled' | null = null
 
         const sendEvent = (event: ExecutionEvent) => {
@@ -1159,10 +1156,6 @@ export async function POST(req: NextRequest, { params }: { params: Promise<{ id:
           if (executionId) {
             await cleanupExecutionBase64Cache(executionId)
           }
-          if (!sseDecremented) {
-            sseDecremented = true
-            decrementSSEConnections('workflow-execute')
-          }
           if (!isStreamClosed) {
             try {
               controller.enqueue(encoder.encode('data: [DONE]\n\n'))
@@ -1174,10 +1167,6 @@ export async function POST(req: NextRequest, { params }: { params: Promise<{ id:
       cancel() {
         isStreamClosed = true
         logger.info(`[${requestId}] Client disconnected from SSE stream`)
-        if (!sseDecremented) {
-          sseDecremented = true
-          decrementSSEConnections('workflow-execute')
-        }
       },
     })
 

apps/sim/app/api/workflows/[id]/executions/[executionId]/stream/route.ts

@@ -7,7 +7,6 @@ import {
   getExecutionMeta,
   readExecutionEvents,
 } from '@/lib/execution/event-buffer'
-import { decrementSSEConnections, incrementSSEConnections } from '@/lib/monitoring/sse-connections'
 import { formatSSEEvent } from '@/lib/workflows/executor/execution-events'
 import { authorizeWorkflowByWorkspacePermission } from '@/lib/workflows/utils'
 
@@ -74,10 +73,8 @@ export async function GET(
 
     let closed = false
 
-    let sseDecremented = false
     const stream = new ReadableStream<Uint8Array>({
       async start(controller) {
-        incrementSSEConnections('execution-stream-reconnect')
         let lastEventId = fromEventId
         const pollDeadline = Date.now() + MAX_POLL_DURATION_MS
 
@@ -145,20 +142,11 @@ export async function GET(
               controller.close()
             } catch {}
           }
-        } finally {
-          if (!sseDecremented) {
-            sseDecremented = true
-            decrementSSEConnections('execution-stream-reconnect')
-          }
         }
       },
       cancel() {
         closed = true
         logger.info('Client disconnected from reconnection stream', { executionId })
-        if (!sseDecremented) {
-          sseDecremented = true
-          decrementSSEConnections('execution-stream-reconnect')
-        }
       },
     })
 

apps/sim/lib/monitoring/memory-telemetry.ts

@@ -1,16 +1,10 @@
 /**
- * Periodic memory telemetry for diagnosing heap growth in production.
- * Logs process.memoryUsage(), V8 heap stats, and active SSE connection
- * counts every 60s, enabling correlation between connection leaks and
- * memory spikes.
+ * Periodic memory telemetry for monitoring heap growth in production.
+ * Logs process.memoryUsage() and V8 heap stats every 60s.
  */
 
 import v8 from 'node:v8'
 import { createLogger } from '@sim/logger'
-import {
-  getActiveSSEConnectionCount,
-  getActiveSSEConnectionsByRoute,
-} from '@/lib/monitoring/sse-connections'
 
 const logger = createLogger('MemoryTelemetry', { logLevel: 'INFO' })
 
@@ -23,16 +17,6 @@ export function startMemoryTelemetry(intervalMs = 60_000) {
   started = true
 
   const timer = setInterval(() => {
-    // Trigger opportunistic (non-blocking) garbage collection if running on Bun.
-    // This signals JSC GC + mimalloc page purge without blocking the event loop,
-    // helping reclaim RSS that mimalloc otherwise retains under sustained load.
-    const bunGlobal = (globalThis as Record<string, unknown>).Bun as
-      | { gc?: (force: boolean) => void }
-      | undefined
-    if (typeof bunGlobal?.gc === 'function') {
-      bunGlobal.gc(false)
-    }
-
     const mem = process.memoryUsage()
     const heap = v8.getHeapStatistics()
 
@@ -49,8 +33,6 @@ export function startMemoryTelemetry(intervalMs = 60_000) {
           ? process.getActiveResourcesInfo().length
           : -1,
       uptimeMin: Math.round(process.uptime() / 60),
-      activeSSEConnections: getActiveSSEConnectionCount(),
-      sseByRoute: getActiveSSEConnectionsByRoute(),
     })
   }, intervalMs)
   timer.unref()