public async Task StartAsync(CancellationToken cancellationToken)
{
var activity = WorkflowActivity.StartHost();
try
{
_shutdown = false;
PersistenceStore.EnsureStoreExists();
await QueueProvider.Start();
await LockProvider.Start();
await _lifeCycleEventHub.Start();
await _searchIndex.Start();
// Event subscriptions are removed when stopping the event hub.
// Add them when starting.
AddEventSubscriptions();
Logger.LogInformation("Starting background tasks");
foreach (var task in _backgroundTasks)
{
task.Start();
}
}
catch (Exception ex)
{
activity.RecordException(ex);
throw;
}
finally
{
activity?.Dispose();
}
}
public async Task <WorkflowExecutorResult> Execute(WorkflowInstance workflow, CancellationToken cancellationToken = default)
{
var wfResult = new WorkflowExecutorResult();
var exePointers = new List <ExecutionPointer>(workflow.ExecutionPointers.Where(x => x.Active && (!x.SleepUntil.HasValue || x.SleepUntil < _datetimeProvider.UtcNow)));
var def = _registry.GetDefinition(workflow.WorkflowDefinitionId, workflow.Version);
if (def == null)
{
_logger.LogError("Workflow {0} version {1} is not registered", workflow.WorkflowDefinitionId, workflow.Version);
return(wfResult);
}
_cancellationProcessor.ProcessCancellations(workflow, def, wfResult);
foreach (var pointer in exePointers)
{
if (!pointer.Active)
{
continue;
}
var step = def.Steps.FindById(pointer.StepId);
if (step == null)
{
_logger.LogError("Unable to find step {0} in workflow definition", pointer.StepId);
pointer.SleepUntil = _datetimeProvider.UtcNow.Add(_options.ErrorRetryInterval);
wfResult.Errors.Add(new ExecutionError
{
WorkflowId = workflow.Id,
ExecutionPointerId = pointer.Id,
ErrorTime = _datetimeProvider.UtcNow,
Message = $"Unable to find step {pointer.StepId} in workflow definition"
});
continue;
}
WorkflowActivity.Enrich(step);
try
{
if (!InitializeStep(workflow, step, wfResult, def, pointer))
{
continue;
}
await ExecuteStep(workflow, step, pointer, wfResult, def, cancellationToken);
}
catch (Exception ex)
{
_logger.LogError(ex, "Workflow {0} raised error on step {1} Message: {2}", workflow.Id, pointer.StepId, ex.Message);
wfResult.Errors.Add(new ExecutionError
{
WorkflowId = workflow.Id,
ExecutionPointerId = pointer.Id,
ErrorTime = _datetimeProvider.UtcNow,
Message = ex.Message
});
_executionResultProcessor.HandleStepException(workflow, def, pointer, step, ex);
Host.ReportStepError(workflow, step, ex);
}
_cancellationProcessor.ProcessCancellations(workflow, def, wfResult);
}
ProcessAfterExecutionIteration(workflow, def, wfResult);
await DetermineNextExecutionTime(workflow, def);
using (var scope = _serviceProvider.CreateScope())
{
var middlewareRunner = scope.ServiceProvider.GetRequiredService <IWorkflowMiddlewareRunner>();
await middlewareRunner.RunExecuteMiddleware(workflow, def);
}
return(wfResult);
}
