DAS-2034 - Remove custom retry logic from HOSS in favour of harmony-service-lib.

CHANGELOG.md

@@ -1,3 +1,10 @@
+## v1.0.1
+### 2023-12-19
+
+This version of HOSS removes custom, redundant download retry logic. Instead
+retries are relied upon from `harmony-service-lib` and for each stage in a
+Harmony workflow.
+
 ## v1.0.0
 ### 2023-10-06
 

docker/service_version.txt

@@ -1 +1 @@
-1.0.0
+1.0.1

hoss/bbox_utilities.py

@@ -58,6 +58,7 @@ def get_request_shape_file(message: Message, working_dir: str,
             raise UnsupportedShapeFileFormat(message.subset.shape.type)
 
         shape_file_url = message.subset.shape.process('href')
+        adapter_logger.info('Downloading request shape file')
         local_shape_file_path = download(shape_file_url, working_dir,
                                          logger=adapter_logger,
                                          access_token=message.accessToken,

hoss/dimension_utilities.py

@@ -17,13 +17,14 @@
 import numpy as np
 
 from harmony.message import Message
+from harmony.message_utility import rgetattr
 from harmony.util import Config
 from varinfo import VarInfoFromDmr
 
 from hoss.bbox_utilities import flatten_list
 from hoss.exceptions import InvalidNamedDimension, InvalidRequestedRange
 from hoss.utilities import (format_variable_set_string, get_opendap_nc4,
-                            get_value_or_default, rgetattr)
+                            get_value_or_default)
 
 
 IndexRange = Tuple[int]

hoss/exceptions.py

@@ -119,14 +119,3 @@ class UrlAccessFailed(CustomError):
     def __init__(self, url, status_code):
         super().__init__('UrlAccessFailed',
                          f'{status_code} error retrieving: {url}')
-
-
-class UrlAccessFailedWithRetries(CustomError):
-    """ This exception is raised when an HTTP request for a given URL has
-        failed a specified number of times.
-
-    """
-    def __init__(self, url):
-        super().__init__('UrlAccessFailedWithRetries',
-                         f'URL: {url} was unsuccessfully requested the '
-                         'maximum number of times.')

hoss/subset.py

@@ -8,6 +8,7 @@
 from typing import List, Set
 
 from harmony.message import Message, Source, Variable as HarmonyVariable
+from harmony.message_utility import rgetattr
 from harmony.util import Config
 from netCDF4 import Dataset
 from numpy.ma import masked
@@ -17,7 +18,7 @@
 from hoss.dimension_utilities import (add_index_range, get_fill_slice,
                                       IndexRanges, is_index_subset,
                                       get_requested_index_ranges,
-                                      prefetch_dimension_variables, rgetattr)
+                                      prefetch_dimension_variables)
 from hoss.spatial import get_spatial_index_ranges
 from hoss.temporal import get_temporal_index_ranges
 from hoss.utilities import (download_url, format_variable_set_string,

hoss/utilities.py

@@ -15,10 +15,7 @@
 from harmony.exceptions import ForbiddenException, ServerException
 from harmony.util import Config, download as util_download
 
-from hoss.exceptions import UrlAccessFailed, UrlAccessFailedWithRetries
-
-
-HTTP_REQUEST_ATTEMPTS = 3
+from hoss.exceptions import UrlAccessFailed
 
 
 def get_file_mimetype(file_name: str) -> Tuple[Optional[str], Optional[str]]:
@@ -90,12 +87,12 @@ def download_url(url: str, destination: str, logger: Logger,
                  access_token: str = None, config: Config = None,
                  data=None) -> str:
     """ Use built-in Harmony functionality to download from a URL. This is
-        expected to be used for obtaining the granule `.dmr` and the granule
-        itself (only the required variables).
+        expected to be used for obtaining the granule `.dmr`, a prefetch of
+        only dimensions and bounds variables, and the subsetted granule itself.
 
-        OPeNDAP can return intermittent 500 errors. This function will retry
-        the original request in the event of a 500 error, but not for other
-        error types. In those instances, the original HTTPError is re-raised.
+        OPeNDAP can return intermittent 500 errors. Retries will be performed
+        by inbuilt functionality in the `harmony-service-lib`. The OPeNDAP
+        errors are captured and re-raised as custom exceptions.
 
         The return value is the location in the file-store of the downloaded
         content from the URL.
@@ -106,32 +103,21 @@ def download_url(url: str, destination: str, logger: Logger,
     if data is not None:
         logger.info(f'POST request data: "{format_dictionary_string(data)}"')
 
-    request_completed = False
-    attempts = 0
-
-    while not request_completed and attempts < HTTP_REQUEST_ATTEMPTS:
-        attempts += 1
-
-        try:
-            response = util_download(
-                url,
-                destination,
-                logger,
-                access_token=access_token,
-                data=data,
-                cfg=config
-            )
-            request_completed = True
-        except ForbiddenException as harmony_exception:
-            raise UrlAccessFailed(url, 400) from harmony_exception
-        except ServerException as harmony_exception:
-            if attempts < HTTP_REQUEST_ATTEMPTS:
-                logger.info('500 error returned, retrying request.')
-            else:
-                raise UrlAccessFailedWithRetries(url) from harmony_exception
-        except Exception as harmony_exception:
-            # Not a 500 error, so raise immediately and exit the loop.
-            raise UrlAccessFailed(url, 'Unknown') from harmony_exception
+    try:
+        response = util_download(
+            url,
+            destination,
+            logger,
+            access_token=access_token,
+            data=data,
+            cfg=config
+        )
+    except ForbiddenException as harmony_exception:
+        raise UrlAccessFailed(url, 400) from harmony_exception
+    except ServerException as harmony_exception:
+        raise UrlAccessFailed(url, 500) from harmony_exception
+    except Exception as harmony_exception:
+        raise UrlAccessFailed(url, 'Unknown') from harmony_exception
 
     return response
 
@@ -159,22 +145,3 @@ def get_value_or_default(value: Optional[float], default: float) -> float:
 
     """
     return value if value is not None else default
-
-
-def rgetattr(input_object, requested_attribute, *args):
-    """ This is a recursive version of the inbuilt `getattr` method, such that
-        it can be called to retrieve nested attributes. For example:
-        the Message.subset.shape within the input Harmony message.
-
-        Note, if a default value is specified, this will be returned if any
-        attribute in the specified chain is absent from the supplied object.
-
-    """
-    if '.' not in requested_attribute:
-        result = getattr(input_object, requested_attribute, *args)
-    else:
-        attribute_pieces = requested_attribute.split('.')
-        result = rgetattr(getattr(input_object, attribute_pieces[0], *args),
-                          '.'.join(attribute_pieces[1:]), *args)
-
-    return result

pip_requirements.txt

@@ -1,7 +1,7 @@
 # This file should contain requirements to be installed via Pip.
 # Open source packages available from PyPI
 earthdata-varinfo ~= 1.0.0
-harmony-service-lib ~= 1.0.23
+harmony-service-lib ~= 1.0.25
 netCDF4 ~= 1.6.4
 numpy ~= 1.24.2
 pyproj ~= 3.6.1

tests/unit/test_utilities.py

@@ -5,13 +5,12 @@
 from harmony.exceptions import ForbiddenException, ServerException
 from harmony.util import config
 
-from hoss.exceptions import UrlAccessFailed, UrlAccessFailedWithRetries
+from hoss.exceptions import UrlAccessFailed
 from hoss.utilities import (download_url, format_dictionary_string,
                             format_variable_set_string,
                             get_constraint_expression, get_file_mimetype,
                             get_opendap_nc4, get_value_or_default,
-                            HTTP_REQUEST_ATTEMPTS, move_downloaded_nc4,
-                            rgetattr)
+                            move_downloaded_nc4)
 
 
 class TestUtilities(TestCase):
@@ -42,11 +41,9 @@ def test_get_file_mimetype(self):
 
     @patch('hoss.utilities.util_download')
     def test_download_url(self, mock_util_download):
-        """ Ensure that the `harmony.util.download` function is called. Also
-            ensure that if a 500 error is returned, the request is retried. If
-            a different HTTPError occurs, the caught HTTPError should be
-            re-raised. Finally, check the maximum number of request attempts is
-            not exceeded.
+        """ Ensure that the `harmony.util.download` function is called. If an
+            error occurs, the caught exception should be re-raised with a
+            custom exception with a human-readable error message.
 
         """
         output_directory = 'output/dir'
@@ -88,14 +85,22 @@ def test_download_url(self, mock_util_download):
             )
             mock_util_download.reset_mock()
 
-        with self.subTest('500 error triggers a retry.'):
+        with self.subTest('500 error is caught and handled.'):
             mock_util_download.side_effect = [self.harmony_500_error,
                                               http_response]
 
-            response = download_url(test_url, output_directory, self.logger)
+            with self.assertRaises(UrlAccessFailed):
+                download_url(test_url, output_directory, self.logger,
+                             access_token, self.config)
 
-            self.assertEqual(response, http_response)
-            self.assertEqual(mock_util_download.call_count, 2)
+            mock_util_download.assert_called_once_with(
+                test_url,
+                output_directory,
+                self.logger,
+                access_token=access_token,
+                data=None,
+                cfg=self.config
+            )
             mock_util_download.reset_mock()
 
         with self.subTest('Non-500 error does not retry, and is re-raised.'):
@@ -116,17 +121,6 @@ def test_download_url(self, mock_util_download):
             )
             mock_util_download.reset_mock()
 
-        with self.subTest('Maximum number of attempts not exceeded.'):
-            mock_util_download.side_effect = [
-                self.harmony_500_error
-            ] * (HTTP_REQUEST_ATTEMPTS + 1)
-            with self.assertRaises(UrlAccessFailedWithRetries):
-                download_url(test_url, output_directory, self.logger)
-
-            self.assertEqual(mock_util_download.call_count,
-                             HTTP_REQUEST_ATTEMPTS)
-            mock_util_download.reset_mock()
-
     @patch('hoss.utilities.move_downloaded_nc4')
     @patch('hoss.utilities.util_download')
     def test_get_opendap_nc4(self, mock_download, mock_move_download):
@@ -259,50 +253,3 @@ def test_get_value_or_default(self):
 
         with self.subTest('Value = None returns the supplied default'):
             self.assertEqual(get_value_or_default(None, 20), 20)
-
-    def test_rgetattr(self):
-        """ Ensure that the recursive function can retrieve nested attributes
-            and uses the default argument when required.
-
-        """
-        class Child:
-            def __init__(self, name):
-                self.name = name
-
-        class Parent:
-            def __init__(self, name, child_name):
-                self.name = name
-                self.child = Child(child_name)
-                self.none = None
-
-        test_parent = Parent('parent_name', 'child_name')
-
-        with self.subTest('Parent level attribute'):
-            self.assertEqual(rgetattr(test_parent, 'name'), 'parent_name')
-
-        with self.subTest('Nested attribute'):
-            self.assertEqual(rgetattr(test_parent, 'child.name'), 'child_name')
-        with self.subTest('Missing parent with default'):
-            self.assertEqual(rgetattr(test_parent, 'absent', 'default'),
-                             'default')
-
-        with self.subTest('Missing child attribute with default'):
-            self.assertEqual(rgetattr(test_parent, 'child.absent', 'default'),
-                             'default')
-        with self.subTest('Child requested, parent missing, default'):
-            self.assertEqual(
-                rgetattr(test_parent, 'none.something', 'default'),
-                'default'
-            )
-
-        with self.subTest('Missing parent, with no default'):
-            with self.assertRaises(AttributeError):
-                rgetattr(test_parent, 'absent')
-
-        with self.subTest('Missing child, with no default'):
-            with self.assertRaises(AttributeError):
-                rgetattr(test_parent, 'child.absent')
-
-        with self.subTest('Child requested, parent missing, no default'):
-            with self.assertRaises(AttributeError):
-                rgetattr(test_parent, 'none.something')