public async Task <DataEventReply> ProcessDataEvent(DataEventRequest req)
{
var workflowDefinition = _registry.RetrieveWorkflow();
int eventSourcePosition = _workTracker.GetPositionInWorkflowForRequest(req.RequestId);
if (eventSourcePosition == workflowDefinition.Steps.Count - 1)
{
// todo here I should finish a span that started all the way when the data chunk was first registered.
_logger.LogInformation("Workflow finished for 1 data chunk");
await _workTrackingSemaphore.WaitAsync();
try
{
_workTracker.MarkWorkAsFinished(req.RequestId);
}
finally
{
_workTrackingSemaphore.Release();
}
return(new DataEventReply
{
IsSuccess = true
});
}
var nextStep = workflowDefinition.Steps[eventSourcePosition + 1];
GrpcChannel channel = null;
var stepTriggerRequest = new StepTriggerRequest
{
Metadata = req.Metadata,
RequestId = Guid.NewGuid().ToString(),
DataSink = nextStep.DataSink,
DataSource = nextStep.DataSource
};
if (_configuration["UseDataLocality"] == "false")
{
await _workTrackingSemaphore.WaitAsync();
try
{
_workTracker.MarkWorkAsFinished(req.RequestId);
}
finally
{
_workTrackingSemaphore.Release();
}
var url =
$"http://{_configuration[$"{nextStep.ComputeImage}_SERVICE_HOST"]}:{_configuration[$"{nextStep.ComputeImage}_SERVICE_PORT"]}";
_logger.LogInformation("Not using data locality, falling back to the service: {url}", url);
await _workTrackingSemaphore.WaitAsync();
try
{
_workTracker.MarkWorkAsStarted(stepTriggerRequest.RequestId, eventSourcePosition + 1, "noName");
}
finally
{
_workTrackingSemaphore.Release();
}
channel = GrpcChannel.ForAddress(url);
}
else
{
await _workTrackingSemaphore.WaitAsync();
try
{
_workTracker.MarkWorkAsFinished(req.RequestId);
var channelChoice =
await this._requestRouter.GetGrpcChannelForRequest(nextStep.ComputeImage,
req.Metadata.DataLocalization);
// The request router will return null if there is no available pod.
if (channelChoice == null)
{
_logger.LogInformation("Channel choice is null. We will re-queue the request");
// TODO this could be a bit more informative (like canRetry=true)
return(new DataEventReply
{
IsSuccess = false
});
}
channel = channelChoice.GrpcChannel;
_workTracker.MarkWorkAsStarted(stepTriggerRequest.RequestId, eventSourcePosition + 1,
channelChoice.PodChoice.Name());
}
catch (Exception e)
{
_logger.LogError(e, "Exception for data locality stuff");
throw;
}
finally
{
_workTrackingSemaphore.Release();
}
}
var client = new SidecarService.SidecarServiceClient(channel);
_logger.LogInformation($"Triggering the computation for a step {nextStep.ComputeImage}");
await client.TriggerStepAsync(stepTriggerRequest);
return(new DataEventReply
{
IsSuccess = true
});
}