Unity: Attach with retry if LUN being modified (#354)

Author: yong-huang

storops/unity/resource/host.py

@@ -236,6 +236,8 @@ def _random_hlu_number(self):
                                                           max=MAX_HLU_NUMBER))
 
     @version('<4.4.0')  # noqa
+    @retry(limit=6, wait=5,
+           on_error=ex.UnityLunModifyByAnotherRequestException)
     @retry(limit=5, on_error=ex.UnityHluNumberInUseError)
     def _attach_with_retry(self, lun_or_snap, skip_hlu_0):
         # Before 4.4.0 (Osprey), it didn't support to pass in hlu when
@@ -251,6 +253,8 @@ def _attach_with_retry(self, lun_or_snap, skip_hlu_0):
             return host_lun.hlu
 
     @version('>=4.4.0')  # noqa
+    @retry(limit=6, wait=5,
+           on_error=ex.UnityLunModifyByAnotherRequestException)
     @retry(limit=5, on_error=ex.UnityHluNumberInUseError)
     def _attach_with_retry(self, lun_or_snap, skip_hlu_0):
         # From 4.4.0 (Osprey), it supported to pass in hlu when attaching LUN,

storops_test/unity/resource/test_host.py

@@ -15,12 +15,13 @@
 #    under the License.
 from __future__ import unicode_literals
 
+import time
 from unittest import TestCase
 
 import ddt
 import mock
 from hamcrest import equal_to, assert_that, instance_of, raises, none, \
-    only_contains, not_none, is_not, calling
+    only_contains, not_none, is_not, calling, greater_than
 
 from storops.exception import UnityHostIpInUseError, \
     UnityResourceNotFoundError, UnityHostInitiatorNotFoundError, \
@@ -376,7 +377,12 @@ def test_detach_with_retry_lun_modified_by_another_request(self):
         def f():
             host.detach(lun)
 
+        start = time.time()
         assert_that(f, raises(UnityLunModifyByAnotherRequestException))
+        end = time.time()
+        # _detach_with_retry retry 20 times with 5s interval, it will take
+        # at least (20 - 1) * 5 = 95s to finish the retries.
+        assert_that(end - start, greater_than(95))
 
     @patch_rest
     def test_attach_attached_hlu(self):
@@ -495,6 +501,24 @@ def test_attach_with_retry_hlu_in_use(self):
             assert_that(calling(host._attach_with_retry).with_args(lun, True),
                         raises(UnityHluNumberInUseError))
 
+    @patch_rest
+    def test_attach_with_retry_lun_modify_by_another_request(self):
+        host = UnityHost(cli=t_rest(), _id='Host_23')
+        lun = UnityLun(_id='sv_5610', cli=t_rest())
+        lun.is_cg_member = False
+        mock_lun_modifying = mock.Mock(
+            side_effect=UnityLunModifyByAnotherRequestException)
+        with mock.patch('storops.unity.resource.host.UnityHost.'
+                        '_modify_hlu',
+                        new=mock_lun_modifying):
+            start = time.time()
+            assert_that(calling(host._attach_with_retry).with_args(lun, True),
+                        raises(UnityLunModifyByAnotherRequestException))
+            end = time.time()
+            # _attach_with_retry retry 6 times with 5s interval, it will take
+            # at least (6 - 1) * 5 = 25s to finish the retries.
+            assert_that(end - start, greater_than(25))
+
     @patch_rest
     def test_attach_with_retry_hlu_in_use_but_no_retry(self):
         host = UnityHost(cli=t_rest(), _id='Host_24')