serialize batch image processing requests

app/api/scene-fusion/route.ts

@@ -56,7 +56,8 @@ const SCENE_FUSION_MODEL_COOLDOWN_MS = 2 * 60 * 1000;
 const SCENE_FUSION_MAX_ITEMS = 10;
 const SCENE_FUSION_REQUEST_STAGGER_MS = 350;
 const SCENE_FUSION_AGENT_TIMEOUT_MS = 20000;
-const SCENE_FUSION_AGENT_MAX_WORKERS = 2;
+const SCENE_FUSION_AGENT_MAX_WORKERS = 1;
+const SCENE_FUSION_PROCESS_MAX_WORKERS = 1;
 const SCENE_FUSION_PRE_RMBG_TIMEOUT_MS = 60_000;
 const SCENE_FUSION_ECHO_HASH_TIMEOUT_MS = 20_000;
 const SCENE_FUSION_ECHO_HASH_THRESHOLD = 8;
@@ -1895,7 +1896,11 @@ export async function POST(request: Request) {
           let nextSceneIndex = 0;
           const workerCount = Math.max(
             1,
-            Math.min(4, candidateModels.length, processedScenes.length)
+            Math.min(
+              SCENE_FUSION_PROCESS_MAX_WORKERS,
+              candidateModels.length,
+              processedScenes.length
+            )
           );
 
           const workers = Array.from({ length: workerCount }, async () => {

components/scene-fusion-view.tsx

@@ -39,6 +39,7 @@ import { cn } from "@/lib/utils";
 const fetcher = (url: string) => fetch(url).then((res) => res.json());
 const MAX_BATCH_ITEMS = 10;
 const BATCH_REQUEST_STAGGER_MS = 700;
+const BATCH_SERIAL_WORKER_COUNT = 1;
 const MULTI_PRODUCT_FAILOVER_MAX_ROUNDS = 5;
 const MULTI_PRODUCT_FAILOVER_RETRY_DELAY_MS = 1500;
 
@@ -977,7 +978,10 @@ export function SceneFusionView({
     );
 
     const queue = [...itemsToProcess];
-    const workerCount = Math.max(1, Math.min(2, queue.length));
+    const workerCount = Math.max(
+      1,
+      Math.min(BATCH_SERIAL_WORKER_COUNT, queue.length)
+    );
     let successCount = 0;
     let failedCount = 0;
 
@@ -1148,7 +1152,10 @@ export function SceneFusionView({
     );
 
     const queue = [...itemsToProcess];
-    const workerCount = Math.max(1, Math.min(3, queue.length));
+    const workerCount = Math.max(
+      1,
+      Math.min(BATCH_SERIAL_WORKER_COUNT, queue.length)
+    );
     let successCount = 0;
     let failedCount = 0;