diff --git a/cvat/apps/dataset_manager/formats/datumaro/export_templates/plugins/cvat_rest_api_task_images.py b/cvat/apps/dataset_manager/formats/datumaro/export_templates/plugins/cvat_rest_api_task_images.py
index 2af31fcc5d0d..9a7a9f06af85 100644
--- a/cvat/apps/dataset_manager/formats/datumaro/export_templates/plugins/cvat_rest_api_task_images.py
+++ b/cvat/apps/dataset_manager/formats/datumaro/export_templates/plugins/cvat_rest_api_task_images.py
@@ -42,32 +42,19 @@ def _download_image(self, item_id):
             frame_ids=[item_id], outdir=self._cache_dir, quality='original')
 
     def _connect(self):
-        if self._session is not None:
+        if self._cvat_cli is not None:
             return
 
-        session = None
-        try:
-            print("Enter credentials for '%s' to read task data:" % \
-                (self._config.server_url))
-            username = input('User: ')
-            password = getpass.getpass()
+        print("Enter credentials for '%s' to read task data:" % \
+            (self._config.server_url))
+        username = input('User: ')
+        password = getpass.getpass()
 
-            session = requests.Session()
-            session.auth = (username, password)
+        session = requests.Session()
 
-            api = CVAT_API_V1(self._config.server_url)
-            cli = CVAT_CLI(session, api)
-
-            self._session = session
-            self._cvat_cli = cli
-        except Exception:
-            if session is not None:
-                session.close()
-
-    def __del__(self):
-        if hasattr(self, '_session'):
-            if self._session is not None:
-                self._session.close()
+        api = CVAT_API_V1(self._config.server_url)
+        cli = CVAT_CLI(session, api, credentials=(username, password))
+        self._cvat_cli = cli
 
     @staticmethod
     def _image_loader(item_id, extractor):
@@ -101,15 +88,13 @@ def __init__(self, url):
                 size = (entry['height'], entry['width'])
             image = Image(data=self._make_image_loader(item_id),
                 path=self._image_local_path(item_id), size=size)
-            item = DatasetItem(id=item_id, image=image)
+            item = DatasetItem(id=osp.splitext(item_filename)[0], image=image)
             items.append((item.id, item))
 
-        items = sorted(items, key=lambda e: int(e[0]))
         items = OrderedDict(items)
         self._items = items
 
         self._cvat_cli = None
-        self._session = None
 
     def __iter__(self):
         for item in self._items.values():
diff --git a/cvat/apps/dataset_manager/task.py b/cvat/apps/dataset_manager/task.py
index f2c40dfd0a17..246d2ef02c1d 100644
--- a/cvat/apps/dataset_manager/task.py
+++ b/cvat/apps/dataset_manager/task.py
@@ -536,6 +536,14 @@ def init_from_db(self):
     def data(self):
         return self.ir_data.data
 
+    def export(self, dst_file, exporter, host='', **options):
+        task_data = TaskData(
+            annotation_ir=self.ir_data,
+            db_task=self.db_job.segment.task,
+            host=host,
+        )
+        exporter(dst_file, task_data, **options)
+
     def import_annotations(self, src_file, importer):
         task_data = TaskData(
             annotation_ir=AnnotationIR(),
@@ -674,6 +682,21 @@ def delete_job_data(pk):
     annotation = JobAnnotation(pk)
     annotation.delete()
 
+def export_job(job_id, dst_file, format_name,
+        server_url=None, save_images=False):
+    # For big tasks dump function may run for a long time and
+    # we dont need to acquire lock after the task has been initialized from DB.
+    # But there is the bug with corrupted dump file in case 2 or
+    # more dump request received at the same time:
+    # https://github.com/opencv/cvat/issues/217
+    with transaction.atomic():
+        job = JobAnnotation(job_id)
+        job.init_from_db()
+
+    exporter = make_exporter(format_name)
+    with open(dst_file, 'wb') as f:
+        job.export(f, exporter, host=server_url, save_images=save_images)
+
 @silk_profile(name="GET task data")
 @transaction.atomic
 def get_task_data(pk):
@@ -722,8 +745,7 @@ def export_task(task_id, dst_file, format_name,
 
     exporter = make_exporter(format_name)
     with open(dst_file, 'wb') as f:
-        task.export(f, exporter, host=server_url,
-            save_images=save_images)
+        task.export(f, exporter, host=server_url, save_images=save_images)
 
 @transaction.atomic
 def import_task_annotations(task_id, src_file, format_name):