diff --git a/src/mito2/src/engine.rs b/src/mito2/src/engine.rs
index 772777d3ad53..af6001e4308e 100644
--- a/src/mito2/src/engine.rs
+++ b/src/mito2/src/engine.rs
@@ -21,6 +21,8 @@ mod append_mode_test;
 #[cfg(test)]
 mod basic_test;
 #[cfg(test)]
+mod batch_open_test;
+#[cfg(test)]
 mod catchup_test;
 #[cfg(test)]
 mod close_test;
@@ -299,8 +301,8 @@ impl EngineInner {
         &self,
         topic: String,
         region_requests: Vec<(RegionId, RegionOpenRequest)>,
-    ) -> Result<Vec<Result<(RegionId, AffectedRows)>>> {
-        let mut response_receivers = Vec::with_capacity(region_requests.len());
+    ) -> Result<Vec<(RegionId, Result<AffectedRows>)>> {
+        let mut responses = Vec::with_capacity(region_requests.len());
         let region_ids = region_requests
             .iter()
             .map(|(region_id, _)| *region_id)
@@ -325,21 +327,18 @@ impl EngineInner {
             },
         ) {
             self.workers.submit_to_worker(region_id, request).await?;
-            response_receivers.push((region_id, receiver));
+            responses.push((region_id, async move { receiver.await.context(RecvSnafu)? }));
         }
         // Waits for entries distribution.
         let distribution =
             common_runtime::spawn_read(async move { distributor.distribute().await });
 
         // Waits for worker returns.
-        let responses = join_all(response_receivers.into_iter().map(
-            |(region_id, receiver)| async move {
-                receiver
-                    .await
-                    .context(RecvSnafu)?
-                    .map(|response| (region_id, response))
-            },
-        ))
+        let responses = join_all(
+            responses
+                .into_iter()
+                .map(|(region_id, rows)| async move { (region_id, rows.await) }),
+        )
         .await;
 
         let _ = distribution.await.context(JoinSnafu)?;
@@ -350,7 +349,7 @@ impl EngineInner {
         &self,
         parallelism: usize,
         requests: Vec<(RegionId, RegionOpenRequest)>,
-    ) -> Result<Vec<Result<(RegionId, AffectedRows)>>> {
+    ) -> Result<Vec<(RegionId, Result<AffectedRows>)>> {
         let semaphore = Arc::new(Semaphore::new(parallelism));
         let (topic_to_region_requests, remaining_region_requests) =
             prepare_batch_open_requests(requests)?;
@@ -375,20 +374,23 @@ impl EngineInner {
         if !remaining_region_requests.is_empty() {
             let mut tasks = Vec::with_capacity(remaining_region_requests.len());
             for (region_id, request) in remaining_region_requests {
-                tasks.push(async move {
+                tasks.push((region_id, async move {
                     let (request, receiver) =
                         WorkerRequest::new_open_region_request(region_id, request, None);
 
                     self.workers.submit_to_worker(region_id, request).await?;
 
-                    receiver
-                        .await
-                        .context(RecvSnafu)?
-                        .map(|response| (region_id, response))
-                })
+                    receiver.await.context(RecvSnafu)?
+                }))
             }
 
-            let r = join_all(tasks).await;
+            let r = join_all(
+                tasks
+                    .into_iter()
+                    .map(|(region_id, rows)| async move { (region_id, rows.await) }),
+            )
+            .await;
+
             responses.extend(r);
         }
 
@@ -487,10 +489,11 @@ impl RegionEngine for MitoEngine {
             .map(|responses| {
                 responses
                     .into_iter()
-                    .map(|response| {
-                        response
-                            .map(|(region_id, row)| (region_id, RegionResponse::new(row)))
-                            .map_err(BoxedError::new)
+                    .map(|(region_id, response)| {
+                        (
+                            region_id,
+                            response.map(RegionResponse::new).map_err(BoxedError::new),
+                        )
                     })
                     .collect::<Vec<_>>()
             })
diff --git a/src/store-api/src/region_engine.rs b/src/store-api/src/region_engine.rs
index ba6c928d097e..3b3ed3b696e8 100644
--- a/src/store-api/src/region_engine.rs
+++ b/src/store-api/src/region_engine.rs
@@ -179,7 +179,7 @@ pub trait RegionScanner: Debug + DisplayAs + Send + Sync {
 
 pub type RegionScannerRef = Arc<dyn RegionScanner>;
 
-pub type BatchResponses = Vec<Result<(RegionId, RegionResponse), BoxedError>>;
+pub type BatchResponses = Vec<(RegionId, Result<RegionResponse, BoxedError>)>;
 
 #[async_trait]
 pub trait RegionEngine: Send + Sync {
@@ -201,9 +201,10 @@ pub trait RegionEngine: Send + Sync {
             tasks.push(async move {
                 // Safety: semaphore must exist
                 let _permit = semaphore_moved.acquire().await.unwrap();
-                self.handle_request(region_id, RegionRequest::Open(request))
-                    .await
-                    .map(|response| (region_id, response))
+                let result = self
+                    .handle_request(region_id, RegionRequest::Open(request))
+                    .await;
+                (region_id, result)
             });
         }