l0lawrence
diff --git a/‎eng/pipelines/templates/steps/build-test.yml
+17-2 b/‎eng/pipelines/templates/steps/build-test.yml
+17-2
diff --git a/‎sdk/cosmos/azure-cosmos/CHANGELOG.md
+17 b/‎sdk/cosmos/azure-cosmos/CHANGELOG.md
+17
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_base.py
+5 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_base.py
+5
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_cosmos_client_connection.py
+24-2 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_cosmos_client_connection.py
+24-2
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_database_account_retry_policy.py
+49 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_database_account_retry_policy.py
+49
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_default_retry_policy.py
+3-2 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_default_retry_policy.py
+3-2
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_endpoint_discovery_retry_policy.py
+7-10 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_endpoint_discovery_retry_policy.py
+7-10
diff --git a/‎sdk/cosmos/azure-cosmos/azure/cosmos/_global_endpoint_manager.py
+41-38 b/‎sdk/cosmos/azure-cosmos/azure/cosmos/_global_endpoint_manager.py
+41-38
@@ -83,11 +83,18 @@ steps:
           }
           Write-Host (Get-Command python).Source
 
+          if ($env:TESTMARKARGUMENT) {
+            $markArg = $env:TESTMARKARGUMENT
+          }
+          else {
+            $markArg = "${{ parameters.TestMarkArgument }}"
+          }
+
           python scripts/devops_tasks/dispatch_tox.py
           "$(TargetingString)"
           ${{ parameters.AdditionalTestArgs }}
           ${{ parameters.CoverageArg }}
-          --mark_arg="${{ parameters.TestMarkArgument }}"
+          --mark_arg="$markArg"
           --service="${{ parameters.ServiceDirectory }}"
           --toxenv="${{ parameters.ToxTestEnv }}"
           --injected-packages="${{ parameters.InjectedPackages }}"
@@ -104,10 +111,18 @@ steps:
           . $(VENV_LOCATION)/bin/activate.ps1
         }
         Write-Host (Get-Command python).Source
+
+        if ($env:TESTMARKARGUMENT) {
+          $markArg = $env:TESTMARKARGUMENT
+        }
+        else {
+          $markArg = "${{ parameters.TestMarkArgument }}"
+        }
+
         python scripts/devops_tasks/dispatch_tox.py "$(TargetingString)" `
           ${{ parameters.AdditionalTestArgs }} `
           ${{ parameters.CoverageArg }} `
-          --mark_arg="${{ parameters.TestMarkArgument }}" `
+          --mark_arg="$markArg" `
           --service="${{ parameters.ServiceDirectory }}" `
           --toxenv="${{ parameters.ToxTestEnv }}" `
           --injected-packages="${{ parameters.InjectedPackages }}" `
 
@@ -1,5 +1,22 @@
 ## Release History
 
+### 4.9.1b3 (2025-02-04)
+
+#### Features Added
+* Improved retry logic by retrying alternative endpoint for writes within a region before performing a cross region retry. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* Added endpoint health check logic during database account calls. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+
+#### Bugs Fixed
+* Fixed unnecessary retries on the wrong region for timout retry policy. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* All client connection errors from aiohttp will be retried. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+
+#### Other Changes
+* Changed defaults for retry delays. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* Changed default connection timeout to be 5 seconds. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* Changed default read timeout to be 65 seconds. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* On database account calls send a client id header for load balancing. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+* Removed aiohttp dependency. See [PR 39390](https://github.com/Azure/azure-sdk-for-python/pull/39390)
+
 ### 4.9.1b2 (2025-01-24)
 
 #### Features Added
 
@@ -119,6 +119,7 @@ def GetHeaders(  # pylint: disable=too-many-statements,too-many-branches
         operation_type: str,
         options: Mapping[str, Any],
         partition_key_range_id: Optional[str] = None,
+        client_id: Optional[str] = None,
 ) -> Dict[str, Any]:
     """Gets HTTP request headers.
 
@@ -131,6 +132,7 @@ def GetHeaders(  # pylint: disable=too-many-statements,too-many-branches
     :param str operation_type:
     :param dict options:
     :param str partition_key_range_id:
+    :param str client_id:
     :return: The HTTP request headers.
     :rtype: dict
     """
@@ -280,6 +282,9 @@ def GetHeaders(  # pylint: disable=too-many-statements,too-many-branches
     if partition_key_range_id is not None:
         headers[http_constants.HttpHeaders.PartitionKeyRangeID] = partition_key_range_id
 
+    if client_id is not None:
+        headers[http_constants.HttpHeaders.ClientId] = client_id
+
     if options.get("enableScriptLogging"):
         headers[http_constants.HttpHeaders.EnableScriptLogging] = options["enableScriptLogging"]
 
 
@@ -25,6 +25,7 @@
 """
 import os
 import urllib.parse
+import uuid
 from typing import Callable, Dict, Any, Iterable, List, Mapping, Optional, Sequence, Tuple, Union, cast, Type
 from typing_extensions import TypedDict
 from urllib3.util.retry import Retry
@@ -109,7 +110,7 @@ class _QueryCompatibilityMode:
     _DefaultStringHashPrecision = 3
     _DefaultStringRangePrecision = -1
 
-    def __init__(
+    def __init__( # pylint: disable=too-many-statements
         self,
         url_connection: str,
         auth: CredentialDict,
@@ -131,6 +132,7 @@ def __init__(
             The default consistency policy for client operations.
 
         """
+        self.client_id = str(uuid.uuid4())
         self.url_connection = url_connection
         self.master_key: Optional[str] = None
         self.resource_tokens: Optional[Mapping[str, Any]] = None
@@ -2555,7 +2557,7 @@ def GetDatabaseAccount(
             url_connection = self.url_connection
 
         headers = base.GetHeaders(self, self.default_headers, "get", "", "", "",
-                                  documents._OperationType.Read,{})
+                                  documents._OperationType.Read,{}, client_id=self.client_id)
         request_params = RequestObject("databaseaccount", documents._OperationType.Read, url_connection)
         result, last_response_headers = self.__Get("", request_params, headers, **kwargs)
         self.last_response_headers = last_response_headers
@@ -2589,6 +2591,26 @@ def GetDatabaseAccount(
             response_hook(last_response_headers, result)
         return database_account
 
+    def _GetDatabaseAccountCheck(
+            self,
+            url_connection: Optional[str] = None,
+            **kwargs: Any
+    ):
+        """Gets database account info.
+
+        :param str url_connection: the endpoint used to get the database account
+        :return: The Database Account.
+        :rtype: documents.DatabaseAccount
+        """
+        if url_connection is None:
+            url_connection = self.url_connection
+
+        headers = base.GetHeaders(self, self.default_headers, "get", "", "", "",
+                                  documents._OperationType.Read,{}, client_id=self.client_id)
+        request_params = RequestObject("databaseaccount", documents._OperationType.Read, url_connection)
+        self.__Get("", request_params, headers, **kwargs)
+
+
     def Create(
         self,
         body: Dict[str, Any],
 
@@ -0,0 +1,49 @@
+# The MIT License (MIT)
+# Copyright (c) 2014 Microsoft Corporation
+
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+"""Internal class for database account retry policy implementation in the
+Azure Cosmos database service.
+"""
+
+class DatabaseAccountRetryPolicy(object):
+    """The database account retry policy which should only retry once regardless of errors.
+    """
+
+    def __init__(self, connection_policy):
+        self.retry_count = 0
+        self.retry_after_in_milliseconds = 0
+        self.max_retry_attempt_count = 1
+        self.connection_policy = connection_policy
+
+    def ShouldRetry(self, exception):  # pylint: disable=unused-argument
+        """Returns true if the request should retry based on the passed-in exception.
+
+        :param exceptions.CosmosHttpResponseError exception:
+        :returns: a boolean stating whether the request should be retried
+        :rtype: bool
+        """
+
+        if self.retry_count >= self.max_retry_attempt_count:
+            return False
+
+        self.retry_count += 1
+
+        return True
@@ -5,6 +5,7 @@
 Cosmos database service.
 """
 from . import http_constants
+from .documents import _OperationType
 
 # pylint: disable=protected-access
 
@@ -36,12 +37,12 @@ def __init__(self, *args):
         self.current_retry_attempt_count = 0
         self.retry_after_in_milliseconds = 1000
         self.args = args
+        self.request = args[0] if args else None
 
     def needsRetry(self, error_code):
         if error_code in DefaultRetryPolicy.CONNECTION_ERROR_CODES:
             if self.args:
-                if (self.args[3].method == "GET") or (http_constants.HttpHeaders.IsQuery in self.args[3].headers) \
-                        or (http_constants.HttpHeaders.IsQueryPlanRequest in self.args[3].headers):
+                if _OperationType.IsReadOnlyOperation(self.request.operation_type):
                     return True
                 return False
             return True
 
@@ -50,14 +50,7 @@ def __init__(self, connection_policy, global_endpoint_manager, *args):
         self.retry_after_in_milliseconds = EndpointDiscoveryRetryPolicy.Retry_after_in_milliseconds
         self.connection_policy = connection_policy
         self.request = args[0] if args else None
-        # clear previous location-based routing directive
-        if self.request:
-            self.request.clear_route_to_location()
 
-            # Resolve the endpoint for the request and pin the resolution to the resolved endpoint
-            # This enables marking the endpoint unavailability on endpoint failover/unreachability
-            self.location_endpoint = self.global_endpoint_manager.resolve_service_endpoint(self.request)
-            self.request.route_to_location(self.location_endpoint)
 
     def ShouldRetry(self, exception):  # pylint: disable=unused-argument
         """Returns true if the request should retry based on the passed-in exception.
@@ -77,12 +70,16 @@ def ShouldRetry(self, exception):  # pylint: disable=unused-argument
 
         self.failover_retry_count += 1
 
-        if self.location_endpoint:
+        if self.request.location_endpoint_to_route:
             if _OperationType.IsReadOnlyOperation(self.request.operation_type):
                 # Mark current read endpoint as unavailable
-                self.global_endpoint_manager.mark_endpoint_unavailable_for_read(self.location_endpoint)
+                self.global_endpoint_manager.mark_endpoint_unavailable_for_read(
+                    self.request.location_endpoint_to_route,
+                    True)
             else:
-                self.global_endpoint_manager.mark_endpoint_unavailable_for_write(self.location_endpoint)
+                self.global_endpoint_manager.mark_endpoint_unavailable_for_write(
+                    self.request.location_endpoint_to_route,
+                    True)
 
         # set the refresh_needed flag to ensure that endpoint list is
         # refreshed with new writable and readable locations
 
@@ -24,7 +24,6 @@
 """
 
 import threading
-from urllib.parse import urlparse
 
 from azure.core.exceptions import AzureError
 
@@ -64,25 +63,28 @@ def get_refresh_time_interval_in_ms_stub(self):
         return constants._Constants.DefaultUnavailableLocationExpirationTime
 
     def get_write_endpoint(self):
-        return self.location_cache.get_write_endpoint()
+        return self.location_cache.get_write_regional_endpoint()
 
     def get_read_endpoint(self):
-        return self.location_cache.get_read_endpoint()
+        return self.location_cache.get_read_regional_endpoint()
+
+    def swap_regional_endpoint_values(self, request):
+        return self.location_cache.swap_regional_endpoint_values(request)
 
     def resolve_service_endpoint(self, request):
         return self.location_cache.resolve_service_endpoint(request)
 
-    def mark_endpoint_unavailable_for_read(self, endpoint):
-        self.location_cache.mark_endpoint_unavailable_for_read(endpoint)
+    def mark_endpoint_unavailable_for_read(self, endpoint, refresh_cache):
+        self.location_cache.mark_endpoint_unavailable_for_read(endpoint, refresh_cache)
 
-    def mark_endpoint_unavailable_for_write(self, endpoint):
-        self.location_cache.mark_endpoint_unavailable_for_write(endpoint)
+    def mark_endpoint_unavailable_for_write(self, endpoint, refresh_cache):
+        self.location_cache.mark_endpoint_unavailable_for_write(endpoint, refresh_cache)
 
-    def get_ordered_write_endpoints(self):
-        return self.location_cache.get_ordered_write_endpoints()
+    def get_ordered_write_locations(self):
+        return self.location_cache.get_ordered_write_locations()
 
-    def get_ordered_read_endpoints(self):
-        return self.location_cache.get_ordered_read_endpoints()
+    def get_ordered_read_locations(self):
+        return self.location_cache.get_ordered_read_locations()
 
     def can_use_multiple_write_locations(self, request):
         return self.location_cache.can_use_multiple_write_locations_for_request(request)
@@ -91,6 +93,9 @@ def force_refresh(self, database_account):
         self.refresh_needed = True
         self.refresh_endpoint_list(database_account)
 
+    def update_location_cache(self):
+        self.location_cache.update_location_cache()
+
     def refresh_endpoint_list(self, database_account, **kwargs):
         if self.location_cache.current_time_millis() - self.last_refresh_time > self.refresh_time_interval_in_ms:
             self.refresh_needed = True
@@ -115,6 +120,8 @@ def _refresh_endpoint_list_private(self, database_account=None, **kwargs):
                 self.last_refresh_time = self.location_cache.current_time_millis()
                 database_account = self._GetDatabaseAccount(**kwargs)
                 self.location_cache.perform_on_database_account_read(database_account)
+                # this will perform getDatabaseAccount calls to check endpoint health
+                self._endpoints_health_check(**kwargs)
 
     def _GetDatabaseAccount(self, **kwargs):
         """Gets the database account.
@@ -137,7 +144,7 @@ def _GetDatabaseAccount(self, **kwargs):
         # to get that info from any endpoints
         except (exceptions.CosmosHttpResponseError, AzureError):
             for location_name in self.PreferredLocations:
-                locational_endpoint = _GlobalEndpointManager.GetLocationalEndpoint(self.DefaultEndpoint, location_name)
+                locational_endpoint = LocationCache.GetLocationalEndpoint(self.DefaultEndpoint, location_name)
                 try:
                     database_account = self._GetDatabaseAccountStub(locational_endpoint, **kwargs)
                     self._database_account_cache = database_account
@@ -146,6 +153,28 @@ def _GetDatabaseAccount(self, **kwargs):
                     pass
             raise
 
+    def _endpoints_health_check(self, **kwargs):
+        """Gets the database account for each endpoint.
+
+        Validating if the endpoint is healthy else marking it as unavailable.
+        """
+        all_endpoints = [self.location_cache.read_regional_endpoints[0]]
+        all_endpoints.extend(self.location_cache.write_regional_endpoints)
+        count = 0
+        for endpoint in all_endpoints:
+            count += 1
+            if count > 3:
+                break
+            try:
+                self.Client._GetDatabaseAccountCheck(endpoint.get_current(), **kwargs)
+            except (exceptions.CosmosHttpResponseError, AzureError):
+                if endpoint in self.location_cache.read_regional_endpoints:
+                    self.mark_endpoint_unavailable_for_read(endpoint.get_current(), False)
+                if endpoint in self.location_cache.write_regional_endpoints:
+                    self.mark_endpoint_unavailable_for_write(endpoint.get_current(), False)
+                    endpoint.swap()
+        self.location_cache.update_location_cache()
+
     def _GetDatabaseAccountStub(self, endpoint, **kwargs):
         """Stub for getting database account from the client.
         This can be used for mocking purposes as well.
@@ -155,29 +184,3 @@ def _GetDatabaseAccountStub(self, endpoint, **kwargs):
         :rtype: ~azure.cosmos.DatabaseAccount
         """
         return self.Client.GetDatabaseAccount(endpoint, **kwargs)
-
-    @staticmethod
-    def GetLocationalEndpoint(default_endpoint, location_name):
-        # For default_endpoint like 'https://contoso.documents.azure.com:443/' parse it to
-        # generate URL format. This default_endpoint should be global endpoint(and cannot
-        # be a locational endpoint) and we agreed to document that
-        endpoint_url = urlparse(default_endpoint)
-
-        # hostname attribute in endpoint_url will return 'contoso.documents.azure.com'
-        if endpoint_url.hostname is not None:
-            hostname_parts = str(endpoint_url.hostname).lower().split(".")
-            if hostname_parts is not None:
-                # global_database_account_name will return 'contoso'
-                global_database_account_name = hostname_parts[0]
-
-                # Prepare the locational_database_account_name as contoso-EastUS for location_name 'East US'
-                locational_database_account_name = global_database_account_name + "-" + location_name.replace(" ", "")
-
-                # Replace 'contoso' with 'contoso-EastUS' and return locational_endpoint
-                # as https://contoso-EastUS.documents.azure.com:443/
-                locational_endpoint = default_endpoint.lower().replace(
-                    global_database_account_name, locational_database_account_name, 1
-                )
-                return locational_endpoint
-
-        return None