Add 'consistencyLevel' to CosmosDB provider. (#79)

Author: StephenMolloy

Readme.md

@@ -49,4 +49,5 @@ The specific settings available for the new session state module and providers a
   * The Sql provider's `UseInMemoryTable` is deprecated. It will continue to be respected in the absence of `RepositoryType`, but is overridden by that setting if given.
   * Sql provider `SessionTableName` - A new setting that allows users to target a specific table in their database rather than being forced to use the default table names.
   * CosmosDB `collectionId` is now `containerId` in keeping with the updated terminology from the CosmosDB offering. Please use the updated parameter name when configuring your provider. (The old name will continue to work just the same.)
+  * Added CosmosDB `consistencyLevel` to allow using a different [Consistency Level](https://learn.microsoft.com/en-us/azure/cosmos-db/consistency-levels) with the CosmosClient.
   * CosmosDB `connectionProtocol` is obsolete. It will not cause errors to have it in configuration, but it is ignored. The current [CosmosDB SDK chooses the protocol based on connection mode](https://learn.microsoft.com/en-us/azure/cosmos-db/nosql/sdk-connection-modes).

docs/CosmosDBSessionStateProviderAsync.md

@@ -9,7 +9,7 @@ Then, register your new provider like so:
     <providers>
       <add name="CosmosDBSessionStateProviderAsync" cosmosDBEndPointSettingKey="cosmosDBEndPointSetting" cosmosDBAuthKeySettingKey="cosmosDBAuthKeySetting"
           databaseId="[DataBaseId]" collectionId="[CollectionId]" offerThroughput="5000" connectionMode="Direct" requestTimeout="5"
-          maxConnectionLimit="50" maxRetryAttemptsOnThrottledRequests="10" maxRetryWaitTimeInSeconds="10" preferredLocations=""
+          maxConnectionLimit="50" maxRetryAttemptsOnThrottledRequests="10" maxRetryWaitTimeInSeconds="10" consistencyLevel="Session" preferredLocations=""
           type="Microsoft.AspNet.SessionState.CosmosDBSessionStateProviderAsync, Microsoft.AspNet.SessionState.CosmosDBSessionStateProviderAsync, Version=1.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
     </providers>
   </sessionState>
@@ -34,4 +34,6 @@ Then, register your new provider like so:
 
 8. *maxRetryWaitTimeInSeconds* - The maximum retry time in seconds for the Azure DocumentDB database service.
 
-9. *preferredLocations* - Sets the preferred locations(regions) for geo-replicated database accounts in the Azure DocumentDB database service. Use ';' to split multiple locations. e.g. "East US;South Central US;North Europe"
+9. *consistencyLevel* - The [Consistency Level](https://learn.microsoft.com/en-us/azure/cosmos-db/consistency-levels) to use with the CosmosClient. Default is the Cosmos SDK default, which is currently 'Session'.
+
+10. *preferredLocations* - Sets the preferred locations(regions) for geo-replicated database accounts in the Azure DocumentDB database service. Use ';' to split multiple locations. e.g. "East US;South Central US;North Europe"

src/CosmosDBSessionStateProviderAsync/CosmosDBSessionStateProviderAsync.cs

@@ -854,6 +854,11 @@ internal static CosmosClientOptions ParseCosmosDBClientSettings(NameValueCollect
                 MaxRetryWaitTimeOnRateLimitedRequests = TimeSpan.FromSeconds(maxRetryWaitTimeInSeconds)
             };
 
+            if (Enum.TryParse<ConsistencyLevel>(config["consistencyLevel"], out ConsistencyLevel consistencyLevel))
+            {
+                clientOptions.ConsistencyLevel = consistencyLevel;
+            }
+
             var preferredLocations = config["preferredLocations"];
             if (!string.IsNullOrEmpty(preferredLocations))
             {

src/packages/CosmosDBSessionStateProviderAsync.nupkg/content/Net462/web.config.install.xdt

@@ -29,9 +29,8 @@
             maxConnectionLimit: maximum number of concurrent connections allowed for the target service endpoint in the Azure DocumentDB database service.
             maxRetryAttemptsOnThrottledRequests: the maximum number of retries in the case where the request fails because the Azure DocumentDB database service has applied rate limiting on the client.
             maxRetryWaitTimeInSeconds: the maximum retry time in seconds for the Azure DocumentDB database service.
+            consistencyLevel: The 'ConsistencyLevel' to use with the CosmosClient. Default is not-specified, leaving the choice to Cosmos SDK. (The current SDK default is 'Session'.)
             preferredLocations: sets the preferred locations(regions) for geo-replicated database accounts in the Azure DocumentDB database service. Use ';' to split multiple locations. e.g. "East US;South Central US;North Europe"
-            partitionKey: the partition key name of the collection
-            partitionNumUsedByProvider: the number of partition can be used for sessionstate
       -->
         <add name="CosmosDBSessionStateProviderAsync" cosmosDBEndPointSettingKey="cosmosDBEndPointSetting" cosmosDBAuthKeySettingKey="cosmosDBAuthKeySetting" databaseId="[DataBaseId]" containerId="[ContainerId]" offerThroughput="5000"
           connectionMode="Direct" requestTimeout="5" maxConnectionLimit="50" maxRetryAttemptsOnThrottledRequests="10" maxRetryWaitTimeInSeconds="10" preferredLocations=""