Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Daniel Marbach (GitHub)

• Added UpdatePrefetchCount methods to ServiceBusProcessor and ServiceBusSessionProcessor to allow updating the prefetch count of a running processor. (A community contribution, courtesy of danielmarbach)

• Update AMQP library dependency to leverage new DrainAsync method.

• Fixed issue with MaxConcurrentCallsPerSession setting which resulted in the setting not always being respected.

• Telemetry will now use a parent activity instead of links when using the ServiceBusProcessor or ServiceBusSessionProcessor.
• Attempt to drain the receiver when closing if there are outstanding credits.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Daniel Marbach (GitHub)

• Fixed issue where shared AMQP session was incorrectly closed when AcceptNextSessionAsync call timed out and EnableCrossEntityTransaction is set to true.
• Dispose semaphores in ServiceBusProcessor to avoid memory leak. (A community contribution, courtesy of danielmarbach)

• Optimized message body copying when accessing the Body property of a received message. (A community contribution, courtesy of danielmarbach)
• Removed locking from the ServiceBusRetryPolicy to improve performance and prevent deadlocks. (A community contribution, courtesy of danielmarbach)
• Added link to troubleshooting guide in exception messages.

• Added DeadletterMessageAsync overload that allows passing the properties dictionary in addition to the deadletter error reason and description.
• Added PeekMessagesAsync method to ProcessorReceiveActions.

• Improved performance of sending messages by using the ServiceBusMessageBatch type, by caching the underlying AMQP message as opposed to recalculating it when sending. Because of this change, any changes to a ServiceBusMessage after it has already been added to the batch will no longer be reflected in the batch and what is ultimately sent to the service. To avoid any issues from this change, ensure that yo are not modifying the ServiceBusMessage after adding it to a batch.

• Fixed performance issues in the ServiceBusSessionProcessor that could lead to thread starvation when using a high number of concurrent sessions.
• Fixed diagnostic tracing of the ServiceBusReceiver.Receive operation to correctly include links to the Message operation for the received messages.
• Fixed issue where the TryTimeout was not respected for times over 1 minute and 5 seconds when attempting to accept the next available session.

• Improved performance of sending messages by using the ServiceBusMessageBatch type, by caching the underlying AMQP message as opposed to recalculating it when sending.

• Added the ability to set the a custom Identifier on the various client options types.
• The processor Identifier will now be included in the underlying receiver logs when using the ServiceBusProcessor or ServiceBusSessionProcessor.
• Added the ability to set a custom endpoint that will be used when connecting to the service, via the ServiceBusClientOptions.CustomEndpointAddress property.
• Added the ReleaseSession and RenewSessionLockAsync methods to the ProcessSessionEventArgs class to allow the user to manage the session in the SessionInitializingAsync and the SessionClosingAsync event handlers.

• Fixed issue where the AMQP footer would not be populated on received messages.
• Fixed issue where the client timeout was not respected when establishing the AMQP connection and the AMQP session.
• Fixed issue where closing the rule manager link could result in the AMQP session being closed even when EnableCrossEntityTransactions is set to true in the ServiceBusClientOptions.

• Reduced memory allocations when converting messages into the underlying AMQP primitives. (A community contribution, courtesy of danielmarbach)

• Stable release of ServiceBusRuleManager.
• EntityPath and FullyQualifiedNamespace are now included on the various processor event args.

• Added ServiceBusRuleManager for managing rules.

• Updated behavior of ServiceBusSessionReceiver.IsClosed to return true if the underlying link was closed.

• Include lock token in additional event source logs.

• Fixed issue that could result in the message lock renewal not being cancelled if the user message handler threw an exception.
• Abandon messages that are received from the ProcessorReceiveActions in the event of the user message handler throwing an exception.

• Added the GetReceiveActions method to ProcessMessageEventArgs and ProcessSessionMessageEventArgs to allow for receiving additional messages from the processor callback.

• ServiceBusTransportMetrics and ServiceBusRuleManager have been removed from the prior beta versions. These will be evaluated for inclusion in a future GA release.

• Prevent exception when stopping processor that can occur if custom registrations were added to the CancellationToken that is exposed via the event args.
• Don't close entire AMQP session when closing individual AMQP links when EnableCrossEntityTransactions is set to true, since with this configuration, all links will share the same session.

• Retries related to accepting sessions when using the ServiceBusSessionProcessor are now logged as Verbose rather than Warning.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Daniel Marbach (GitHub)

• Added ServiceBusTransportMetrics that can be used to get transport metric information.

• Relaxed ServiceBusMessage validation to allow the SessionId property to be changed after the PartitionKey property is already set.

• Removed allocations and boxing from EventSource logging. (A community contribution, courtesy of danielmarbach)

• Added the ServiceBusRuleManager which allows managing rules for subscriptions.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Daniel Marbach (GitHub)

• Add the ability to manually renew message and session locks when using the processor.

• Fixed name of ServiceBusAdministrationClient extension method.
• Fixed entity name validation when passing in a subscription entity path into the CreateReceiver method.

• Removed LINQ allocations when sending messages. (A community contribution, courtesy of danielmarbach)

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Max Hamulyak (GitHub)
• Daniel Marbach (GitHub)

• Fix unnecessary task scheduling in ServiceBusProcessor and ServiceBusSessionProcessor
• Remove array allocation when creating linked token sources from the ServiceBusProcessor

• The State property has been added to ServiceBusReceivedMessage which indicates whether a message is Active, Scheduled, or Deferred. (A community contribution, courtesy of danielmarbach)

• Extension methods have been added for registering the ServiceBusAdministrationClient via dependency injection for use in ASP.NET Core applications. (A community contribution, courtesy of kaylumah)

• Support for cancellation tokens has been improved for AMQP operations, enabling earlier detection of cancellation requests without needing to wait for the configured timeout to elapse.

• Add a delay when retrying if we are being throttled by the service.

• Default To, ReplyTo, and CorrelationId properties of ServiceBusMessage to null, rather than empty string. To retain the old behavior, you can set the properties to empty string when constructing your message:

var message = new ServiceBusMessage
{
    ReplyTo = "",
    To = "",
    CorrelationId = ""
};

• Fixed memory leak in ServiceBusSessionProcessor.
• Fixed bug where AMQP sequence/value messages could not be created from a received message.
• Fixed bug where a named session of empty string could not be accepted.

• Added support for specifying the maximum message size for entities in Premium namespaces.

• Added support for cancelling send and receives while in-flight.

• Leveraged fix in AMQP library that allows messages to be properly unlocked when shutting down the processor.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• John Call (GitHub)

• Fixed an issue with refreshing authorization where redundant requests were made to acquire AAD tokens that were due to expire. Refreshes will now coordinate to ensure a single AAD token acquisition.

• Fixed an issue with authorization refresh where attempts may have been made to authorize a faulted link. Links that fail to open are no longer be considered valid for authorization.

• Serialization of messages read from Service Bus has been tweaked for greater efficiency. (A community contribution, courtesy of johnthcall)

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Timothee Lecomte (GitHub)
• Shlomi Assaf (GitHub)

• Added the ReleaseSession method to ProcessSessionMessageEventArgs which allows processing for a session to terminated early.
• Added protected constructors to ServiceBusProcessor, ServiceBusReceiver, ServiceBusSender, and ServiceBusSessionProcessor to allow these types to be extended.
• Added UpdateConcurrency methods to ServiceBusProcessor and ServiceBusSessionProcessor to allow concurrency to be changed for an already created processor.
• Allow a TimeSpan of zero to be passed as the maxWaitTime for the various receive overloads if Prefetch mode is enabled.

• Fixed bug where receiving a message with AbsoluteExpiryTime of DateTime.MaxValue would cause an `ArgumentException'. (A community contribution, courtesy of tlecomte)

• Fixed reference name conflicts in ServiceBusModelFactory ref docs. (A community contribution, courtesy of shlomiassaf)

• Fixed bug in the ServiceBusProcessor where message locks stopped being automatically renewed after StopProcessingAsync was called.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Jason Dryhurst-Smith (GitHub)
• Oscar Cabrero (GitHub)

• The retry policy used by clients will no longer overflow the TimeSpan maximum when using an Exponential strategy with a large number of retries and long delay set.

• The name of the property displayed in the ArgumentOutOfRangeException in the MaxDeliveryCount property in SubscriptionProperties was updated to use the correct property name. (A community contribution, courtesy of oscarcabrero)

• Added SubQueue option to ServiceBusProcessorOptions to allow for processing the deadletter queue
• Added Verbose event source events for the following scenarios that previously had Error events which resulted in unnecessary noise in application logs:
  • Accepting a session times out because there are no sessions available.
  • TaskCanceledException occurs while stopping the processor.

• Updated dependency on Microsoft.Azure.Amqp to benefit from a performance enhancement involving message settlement.
• Updated dependency on System.Text.Encodings.Web

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Daniel Marbach (GitHub)
• Mikael Kolkinn

• Updated dependency on Azure.Core.Amqp to support Value/Sequence AMQP message bodies.
• Updated dependency on Microsoft.Azure.Amqp to benefit from a performance enhancement involving message settlement.
• Added OnProcessMessageAsync and OnProcessErrorAsync methods to help with mocking scenarios involving the processor.
• Added the ability to construct a ServiceBusClient and ServiceBusAdministrationClient using the AzureNamedKeyCredential and AzureSasCredential types to allow for updating credentials for long-lived clients.
• Added the ability to cancel receive operations which allows StopProcessingAsync calls on the processor to complete more quickly. (A community contribution, courtesy of danielmarbach)

• Multiple enhancements were made to the transport paths for publishing and reading events to reduce memory allocations and increase performance. (A community contribution, courtesy of danielmarbach)
• Fixed an issue where constructing a new CreateRuleOption from a RuleProperties would fail if the CorrelationId was null. (A community contribution, courtesy of Mikael Kolkinn

• Fixed issue where batch size calculation was not taking diagnostic tracing information into account.

• Added EnableCrossEntityTransactions property to ServiceBusClientOptions to support transactions spanning multiple entities.
• Added SessionIdleTimeout property to ServiceBusSessionProcessorOptions to allow configuration of when to switch to the next session when using the session processor.

• Fixed issue where batch size calculation was not taking diagnostic tracing information into account.
• Retry on authorization failures to reduce likelihood of transient failures bubbling up to user application.
• Reduce maximum refresh interval to prevent Timer exceptions involving long-lived SAS tokens.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions to this release:

• Aaron Dandy (GitHub)

• Added virtual keyword to all client properties to enable mocking scenarios.
• Added ServiceBusModelFactory.ServiceBusMessageBatch to allow mocking a ServiceBusMessageBatch.

• Fixed an issue with the ServiceBusProcessor where closing and disposing or disposing multiple times resulted in an exception. (A community contribution, courtesy of aarondandy)
• Fixed issue with batch size calculation when using ServiceBusMessageBatch.

• Fixed race condition that could occur when using the same ServiceBusSessionReceiverOptions instance for several receivers.
• Increased the authorization refresh buffer to make it less likely that authorization will expire.

• Renamed GetRawMessage method to GetRawAmqpMessage.
• Removed LinkCloseMode.
• Rename ReceiveMode type to ServiceBusReceiveMode.
• Remove ServiceBusFailureReason of Unauthorized in favor of using UnauthorizedAccessException.

• Added dependency on Azure.Core.Amqp library.
• Added dependency on System.Memory.Data library.

• Removed AmqpMessage property in favor of a GetRawMessage method on ServiceBusMessage and ServiceBusReceivedMessage.
• Renamed Properties to ApplicationProperties in CorrelationRuleFilter.
• Removed ServiceBusSenderOptions.
• Removed TransactionEntityPath from ServiceBusSender.

• Added AcceptSessionAsync that accepts a specific session based on session ID.

• Renamed ViaQueueOrTopicName to TransactionQueueOrTopicName.
• Renamed ViaPartitionKey to TransactionPartitionKey.
• Renamed ViaEntityPath to TransactionEntityPath.
• Renamed Proxy to WebProxy.
• Made MaxReceiveWaitTime in ServiceBusProcessorOptions and ServiceBusSessionProcessorOptions internal.
• Renamed CreateSessionReceiverAsync to AcceptNextSessionAsync.
• Removed SessionId from ServiceBusClientOptions in favor of AcceptSessionAsync.

• Added AmqpMessage property on ServiceBusMessage and ServiceBusReceivedMessage that gives full access to underlying AMQP details.
• Added explicit Close methods on ServiceBusReceiver, ServiceBusSessionReceiver, ServiceBusSender, ServiceBusProcessor, and ServiceBusSessionProcessor.

• Renamed ServiceBusManagementClient to ServiceBusAdministrationClient.
• Renamed ServiceBusManagementClientOptions to ServiceBusAdministrationClientOptions.
• Renamed IsDisposed to IsClosed on ServiceBusSender, ServiceBusReceiver, and ServiceBusSessionReceiver.
• Made ServiceBusProcessor and ServiceBusSessionProcessor implement IAsyncDisposable
• Removed public constructors for QueueProperties and RuleProperties.
• Added version parameter to ServiceBusAdministrationClientOptions constructor.
• Removed CreateDeadLetterReceiver methods in favor of new SubQueue property on ServiceBusReceiverOptions.
• Made EntityNameFormatter internal.
• Made settlement methods on ProcessMessageEventArgs and ProcessSessionMessageEventArgs virtual for mocking.
• Made all Create methods on ServiceBusClient virtual for mocking.

• Bug in TaskExtensions.EnsureCompleted method that causes it to unconditionally throw an exception in the environments with synchronization context

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions and design input for this release:

• Daniel Marbach (GitHub)
• Sean Feldman (GitHub)

• Added MaxConcurrentCallsPerSession option to ServiceBusSessionProcessor

• Change MaxConcurrentCalls to MaxConcurrentSessions in ServiceBusSessionProcessor.
• Replace (Queue|Topic|Subscription|Rule)Description with (Queue|Topic|Subscription|Rule)Properties.
• Add Create(Queue|Topic|Subscription|Rule)Options for creating entities.
• Replace (Queue|Topic|Subscription)RuntimeInfo with (Queue|Topic|Subscription)RuntimeProperties.
• Remove MessageCountDetails and move the properties directly into the RuntimeProperties types.

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions and design input for this release:

• Daniel Marbach (GitHub)
• Sean Feldman (GitHub)

• Add IAsyncEnumerable Receive overload
• Add batch schedule/cancel schedule messages

• Remove use of "Batch" in Peek/Receive methods.
• Add Message/Messages suffix to Peek/Send/Receive/Abandon/Defer/Complete/DeadLetter methods.
• Rename ServiceBusSender.CreateBatch to ServiceBusSender.CreateMessageBatch
• Rename CreateBatchOptions to CreateMessageBatchOptions
• Rename ServiceBusMessageBatch.TryAdd to ServiceBusMessageBatch.TryAddMessage
• Change output list type from IList to IReadOnlyList
• Removed ServiceBusException.FailureReason.ClientClosed in favor of throwing ObjectDisposedException

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions and design input for this release:

• Daniel Marbach (GitHub)
• Sean Feldman (GitHub)

• Add the ServiceBusManagementClient for CRUD operations on a namespace
• Add constructor for ServiceBusMessage taking a string
• Use the BinaryData type for ServiceBusMessage.Body
• Add diagnostic tracing

• Introduce ServiceBusSessionReceiverOptions/ServiceBusSessionProcessorOptions for creating ServiceBusSessionReceiver/ServiceBusSessionProcessor
• Make ServiceBusReceivedMessage.Properties IReadOnlyDictionary rather than IDictionary

Thank you to our developer community members who helped to make the Service Bus client library better with their contributions and design input for this release:

• Daniel Marbach (GitHub)
• Sean Feldman (GitHub)

• Allow specifying a list of named sessions when using ServiceBusSessionProcessor
• Transactions/Send via support
• Add SessionInitializingAsync/SessionClosingAsync events in ServiceBusSessionProcessor
• Do not attempt to autocomplete messages with the processor if the user settled the message in their callback
• Add SendAsync overload accepting an IEnumerable of ServiceBusMessage
• Various performance improvements
  (A community contribution, courtesy of danielmarbach)
• Improve the way exception stack traces are captured
  (A community contribution, courtesy of danielmarbach)

• Change from using a static factory method for creating a sendable message from a received message to instead using a constructor
  (A community contribution, courtesy of danielmarbach)
• CreateSessionProcessor parameter sessionId renamed to sessionIds (also changed from string to params string array).
• Remove cancellation token from CreateProcessor and CreateSessionProcessor
  (A community contribution, courtesy of danielmarbach)
• Rename SendBatchAsync to SendAsync
• Add SenderOptions parameter to CreateSender method.

• Initial preview for new version of Service Bus library.
• Includes sending/receiving/settling messages from queues/topics and session support.