diff --git a/src/mito2/src/engine/tests.rs b/src/mito2/src/engine/tests.rs
index 5bd934abbcdd..15af842799f8 100644
--- a/src/mito2/src/engine/tests.rs
+++ b/src/mito2/src/engine/tests.rs
@@ -19,15 +19,22 @@ use store_api::storage::RegionId;
 use super::*;
 use crate::error::Error;
 use crate::test_util::{CreateRequestBuilder, TestEnv};
+use crate::worker::request::RegionOptions;
 
 #[tokio::test]
 async fn test_engine_new_stop() {
     let env = TestEnv::with_prefix("engine-stop");
     let engine = env.create_engine(MitoConfig::default()).await;
 
+    let region_id = RegionId::new(1, 1);
+    let request = CreateRequestBuilder::new(region_id).build();
+    engine.create_region(request).await.unwrap();
+
+    // Stop the engine to reject further requests.
     engine.stop().await.unwrap();
+    assert!(!engine.is_region_exists(region_id));
 
-    let request = CreateRequestBuilder::new(RegionId::new(1, 1)).build();
+    let request = CreateRequestBuilder::new(RegionId::new(1, 2)).build();
     let err = engine.create_region(request).await.unwrap_err();
     assert!(
         matches!(err, Error::WorkerStopped { .. }),
@@ -74,3 +81,92 @@ async fn test_engine_create_existing_region() {
         "unexpected err: {err}"
     );
 }
+
+#[tokio::test]
+async fn test_engine_open_empty() {
+    let env = TestEnv::with_prefix("open-empty");
+    let engine = env.create_engine(MitoConfig::default()).await;
+
+    let err = engine
+        .open_region(OpenRequest {
+            region_id: RegionId::new(1, 1),
+            region_dir: "empty".to_string(),
+            options: RegionOptions::default(),
+        })
+        .await
+        .unwrap_err();
+    assert!(
+        matches!(err, Error::RegionNotFound { .. }),
+        "unexpected err: {err}"
+    );
+}
+
+#[tokio::test]
+async fn test_engine_open_existing() {
+    let env = TestEnv::with_prefix("open-exiting");
+    let engine = env.create_engine(MitoConfig::default()).await;
+
+    let region_id = RegionId::new(1, 1);
+    let request = CreateRequestBuilder::new(region_id).build();
+    let region_dir = request.region_dir.clone();
+    engine.create_region(request).await.unwrap();
+
+    engine
+        .open_region(OpenRequest {
+            region_id,
+            region_dir,
+            options: RegionOptions::default(),
+        })
+        .await
+        .unwrap();
+}
+
+#[tokio::test]
+async fn test_engine_close_region() {
+    let env = TestEnv::with_prefix("close");
+    let engine = env.create_engine(MitoConfig::default()).await;
+
+    let region_id = RegionId::new(1, 1);
+    let request = CreateRequestBuilder::new(region_id).build();
+    engine.create_region(request).await.unwrap();
+
+    engine
+        .close_region(CloseRequest { region_id })
+        .await
+        .unwrap();
+    assert!(!engine.is_region_exists(region_id));
+
+    // It's okay to close this region again.
+    engine
+        .close_region(CloseRequest { region_id })
+        .await
+        .unwrap();
+}
+
+#[tokio::test]
+async fn test_engine_reopen_region() {
+    let env = TestEnv::with_prefix("reopen-region");
+    let engine = env.create_engine(MitoConfig::default()).await;
+
+    let region_id = RegionId::new(1, 1);
+    let request = CreateRequestBuilder::new(region_id).build();
+    let region_dir = request.region_dir.clone();
+    engine.create_region(request).await.unwrap();
+
+    // Close the region.
+    engine
+        .close_region(CloseRequest { region_id })
+        .await
+        .unwrap();
+
+    // Open the region again.
+    engine
+        .open_region(OpenRequest {
+            region_id,
+            region_dir,
+            options: RegionOptions::default(),
+        })
+        .await
+        .unwrap();
+    assert!(engine.is_region_exists(region_id));
+}
diff --git a/src/mito2/src/region.rs b/src/mito2/src/region.rs
index 358a121245ad..a143305be057 100644
--- a/src/mito2/src/region.rs
+++ b/src/mito2/src/region.rs
@@ -88,6 +88,17 @@ impl RegionMap {
         let mut regions = self.regions.write().unwrap();
         regions.remove(&region_id);
     }
+
+    /// List all regions.
+    pub(crate) fn list_regions(&self) -> Vec<MitoRegionRef> {
+        let regions = self.regions.read().unwrap();
+        regions.values().cloned().collect()
+    }
+
+    /// Clear the map.
+    pub(crate) fn clear(&self) {
+        self.regions.write().unwrap().clear();
+    }
 }
 
 pub(crate) type RegionMapRef = Arc<RegionMap>;
diff --git a/src/mito2/src/worker.rs b/src/mito2/src/worker.rs
index 200f1131bd66..d308f5c128c3 100644
--- a/src/mito2/src/worker.rs
+++ b/src/mito2/src/worker.rs
@@ -313,6 +313,8 @@ impl<S> RegionWorkerLoop<S> {
             self.handle_requests(&mut buffer).await;
         }
 
+        self.clean().await;
+
         logging::info!("Exit region worker thread {}", self.id);
     }
 
@@ -378,6 +380,19 @@ impl<S> RegionWorkerLoop<S> {
             }
         }
     }
+
+    // Clean up the worker.
+    async fn clean(&self) {
+        // Closes remaining regions.
+        let regions = self.regions.list_regions();
+        for region in regions {
+            if let Err(e) = region.stop().await {
+                logging::error!(e; "Failed to stop region {}", region.region_id);
+            }
+        }
+
+        self.regions.clear();
+    }
 }
 
 #[cfg(test)]