Unity: Detach host with retry (#346)

Author: yong-huang

storops/exception.py

@@ -1510,3 +1510,8 @@ class UnityCompressionRequireAllFlashPoolError(UnityException):
 @rest_exception
 class UnityQuotaConfigModifyException(UnityException):
     error_code = 0x900022a
+
+
+@rest_exception
+class UnityLunModifyByAnotherRequestException(UnityException):
+    error_code = 108008704

storops/unity/resource/host.py

@@ -191,7 +191,10 @@ def _get_host_luns(self, lun=None, snap=None, hlu=None):
 
             return ret
 
-    def detach(self, lun_or_snap):
+    @retry(limit=20, wait=5,
+           on_error=ex.UnityLunModifyByAnotherRequestException)
+    def _detach_with_retry(self, lun_or_snap):
+        lun_or_snap.update()
         if self.host_luns:
             # To detach the `dummy luns` which are attached via legacy storops.
             dummy_lun_ids = [lun.get_id() for lun in self.host_luns.lun
@@ -205,6 +208,14 @@ def detach(self, lun_or_snap):
                     pass
         return lun_or_snap.detach_from(self)
 
+    def detach(self, lun_or_snap):
+        try:
+            return self._detach_with_retry(lun_or_snap)
+        except ex.UnityLunModifyByAnotherRequestException:
+            log.error('Failed to detach lun or snap {} from host with '
+                      '20 times retry.'.format(lun_or_snap.name))
+            raise
+
     def detach_alu(self, lun):
         log.warn('Method detach_alu is deprecated. Use detach instead.')
         return lun.detach_from(self)

storops_test/unity/resource/test_host.py

@@ -28,7 +28,8 @@
     UnityAttachAluExceedLimitError, UnitySnapAlreadyPromotedException, \
     SystemAPINotSupported, UnityHostInitiatorExistedError, \
     UnityResourceNotAttachedError, UnityNoHluAvailableError, \
-    UnityHluNumberInUseError, UnityAttachExceedLimitError
+    UnityHluNumberInUseError, UnityAttachExceedLimitError, \
+    UnityLunModifyByAnotherRequestException
 from storops.unity.enums import HostTypeEnum, HostManageEnum, \
     HostPortTypeEnum, HealthEnum, HostInitiatorTypeEnum, \
     HostInitiatorSourceTypeEnum, HostInitiatorIscsiTypeEnum
@@ -367,6 +368,16 @@ def test_detach_alu(self):
         resp = host.detach_alu(lun)
         assert_that(resp.is_ok(), equal_to(True))
 
+    @patch_rest
+    def test_detach_with_retry_lun_modified_by_another_request(self):
+        host = UnityHost(cli=t_rest(), _id='Host_10')
+        lun = UnityLun(_id='sv_5', cli=t_rest())
+
+        def f():
+            host.detach(lun)
+
+        assert_that(f, raises(UnityLunModifyByAnotherRequestException))
+
     @patch_rest
     def test_attach_attached_hlu(self):
         host = UnityHost(cli=t_rest(), _id='Host_10')

storops_test/unity/rest_data/storageResource/index.json

@@ -884,6 +884,22 @@
       },
       "response": "empty.json"
     },
+    {
+      "url": "/api/instances/storageResource/sv_5/action/modifyLun?compact=True",
+      "body": {
+        "lunParameters": {
+          "hostAccess": [
+            {
+              "host": {
+                "id": "Host_1"
+              },
+              "accessMask": 3
+            }
+          ]
+        }
+      },
+      "response": "lun_modified_by_another_request.json"
+    },
     {
       "url": "/api/instances/storageResource/sv_6/action/modifyLun?compact=True",
       "body": {

storops_test/unity/rest_data/storageResource/lun_modified_by_another_request.json

@@ -0,0 +1,12 @@
+{
+  "error": {
+    "errorCode": 108008704,
+    "httpStatusCode": 409,
+    "messages": [
+      {
+        "en-US": "The requested operation has failed because the LUN has already been modified by another request. Please retry. (Error Code:0x6701500)"
+      }
+    ],
+    "created": "2021-05-11T03:52:56.102Z"
+  }
+}