What's New?

• New Features
  • Added the ability to restrict a task to agents running a specific OS by adding OSPlatform to CommonResources and adding OSPlatform enumeration. See TaskPreconditions for an example using CommonResources.

• Minor bug fixes and improvements.

• Updated the minimum required version of the Microsoft .NET Core SDK to Microsoft .NET SDK 5.0.0.

• Updated to work with Ansys licensing.

• The Coordinator Service and Agent Service are now available for use on Linux.
• A new Host that supports .NET Core 3.0+ client applications has been added.

• The Coordinator Service, Agent Service, BookKeeper Service, and accompanying Tray Applications have been migrated to .NET Core 3.0.

• The product formerly known as STK Scalability Extension has been renamed to STK Parallel Computing Server.
• The STK Parallel Computing Server API for .NET now requires a minimum version of .NET 4.7.2 (instead of 4.5.2 in the previous version).

• The STK Scalability API for .NET now requires .NET 4.5.2 (instead of 4.5 in previous versions).

• New Features
  • Added the ability to specify a task's estimated memory usage (TaskPropertiesEstimatedMemoryUsageForTask), which is then taken into account to honor the Agent's Estimated Memory Budget (EstimatedMemoryBudget). This facilitates worker process assignments when using tasks that require a large amount of memory. See the discussion section of the help topic Constrain the amount of resources required for a task to be scheduled for more details.

• Updated for Coordinator and Agent services 1.6.

• The default installation location has been changed from C:\Program Files (x86) to C:\Program Files.

• New Features
  • Before, the host would always start with Server garbage collection. The user may now programmatically specify whether the host will use Server garbage collection or Workstation garbage collection via the HostGcMode property.
• Improvements
  • Log files and the communication protocol used between the clients, coordinator, and agents have been changed to use UTF-8 encoding. This provides better support for extended characters and is backwards compatible with the previously used ASCII encoding.
• Bug Fixes
  • Fixed an issue with reporting "Additional Dependencies" on a custom TaskEnvironment that would prevent further serialization from a Task to a ChildTask.

• New Features
  • Added the option for a Coordinator using secure connections (TLS 1.2) to require clients to provide security certificates for validation (mutual SSL). Read the updated Connect to the Coordinator with TLS1.2 topic for details.
  • Added a new IsFinishedTaskStatus property to Task to help determine which TaskStatuses are interpreted as finished.
• Improvements
  • Improved assembly serialization to minimize Large Object Heap (LOH) fragmentation.
• Bug Fixes
  • AddTask now throws an ArgumentException when trying to add the same task to a job more than once to prevent a case where a job would never finish.

• The minimum version of the Microsoft .NET Framework required has changed from 3.5 to 4.5.

• New Features
  • New options to secure communications between the coordinator and agents/clients using SSL (TLS v1.2) have been added. Read the new Connect to the Coordinator with TLS1.2 topic for details.

• New Features
  • New options to control the lifetime of host processes have been added. Hosts are recyclable after any one of a variety of time, memory, or job-based conditions have been satisfied. The Agent Tray Application has a new Host Recycling panel to set values for these options. The values set in the Agent Tray Application UI will be overridden if a submitted job's TaskEnvironment's RecycleSettings have been set programmatically.
• Improvements
  • Reduced the amount of logging the external capability checkers generated in the agent log.
  • Improved capture of task standard output.
• Bug Fixes
  • Fixed a bug where running parallel coverage with tirem could cause a host to hang in rare conditions.

• The product formerly known as STK Server has been renamed to STK Scalability Extension.

• New Features
  • Clients now automatically try to reconnect to the coordinator if the network connection between the two is lost. This behavior is controlled by the new properties (CoordinatorReconnectionDelay, CoordinatorReconnectionInterval, and MaximumReconnectionAttempts) added to the ClusterJobScheduler class and exposed via a new client configuration file (ClientSettings.config).
  • Tasks have a new readable property, TaskPropertiesInterruptedRetryAttempts, which specifies the number of times a task has been retried after its execution has been interrupted (e.g. by a terminating process).
• Improvements
  • Added a new throttling capability to the coordinator to better manage its memory usage when running jobs with high memory requirements.
  • Improved memory management when executing tasks with large payloads/results.
  • The detection of unresponsive elements in the system and their associated heartbeat messages used to rely on the local machine time and could therefore be wrongfully triggered if the local machine time was modified (e.g. manually or due to daylight savings). This logic has been reworked to no longer depend on the local machine time and is thus now immune to local machine time modifications.
  • Any non-default configuration value is now logged.
  • Added caching for the byte arrays used during message serialization to improve performance. The use of byte[] has been replaced by ChunkedByteArray in some functions and properties, e.g., NonSerializableObjectPayload.
• Bug Fixes
  • Fixed a race condition that could result in the agent service crashing if a host repeatedly failed after finishing a task.
  • Fixed the documentation on the expected behavior when JobRaiseEventsUsingSynchronizationContext is true.
  • In some cases, IJobSchedulerContextReserveResource would return an exception without waiting for the resouces to be available. This has been fixed and IJobSchedulerContextReserveResource will now block until the requested resources become available or the specified timeout expires.
  • Fixed spurious debug messages in the agent log relating to invalid format strings.
  • Fixed a bug where the agent service might not have retried a task when the host failed to start due to low memory conditions. In these cases the task will now be retried similarly to the other failure cases.

• New Features
  • Message passing capabilities added. Both IJobScheduler and IJobSchedulerContext inherit from IMessageEndpoint. Message passing allows tasks and clients to communicate with each other dynamically. It also offers a way to pass data to a task with a low communication overhead.
  • Added ability for a task to spawn sub-jobs. A sub job can be created by calling CreateChildJob.
  • Added ability for a task to dynamically control the resources allocated to a task. For more information see Dynamically control the resources allocated to task.
  • Added new examples that demonstrate how to use this product with other AGI Products. For more information see What's included in the Software Developer Kit.
• Improvements
  • Added a new task property that can return a IJobSchedulerContext interface. This interface is available in the task properties collection with the TaskPropertiesJobSchedulerContext key.
  • If the host encounters an OutOfMemoryException exception during task serialization, the task will enter the Interrupted state.
  • Numerous improvements to the examples and documentation.
  • Java is supported as a new client language.
• Bug Fixes
  • Fixed a bug where the host wasn't killed after a timeout that results after TaskExecutionTimeout.
  • Fixed a bug where canceling a job in the EmbeddedJobScheduler will only cancel the first job.

• New Features
  • New developer documentation and examples.
• Improvements
  • Improved performance when submitting numerous jobs. The number of maximum concurrent jobs that can be submitted can be configured with the MaxConcurrentJobSubmissions property.
  • Improved how unserializable exceptions get handled. If a thrown exception is unserializable, an Exception object is thrown that contains the message of the original exception.
  • Added a way to wait for a task to finish canceling. You can pass true to the Cancel method and WaitUntilDone will not unblock until the task is finished canceling.
• Bug Fixes
  • Fixed a bug where a custom configuration specified with SetConfigurationFile was not deleted after the host shuts down.

The first release of the API for .NET!