const int MaxReceiveBatchSize = 1000; // actual batches are typically much smaller
public PartitionInstance(uint partitionId, int incarnation, ScriptedEventProcessorHost eventProcessorHost)
{
this.partitionId = partitionId;
this.Incarnation = incarnation;
this.host = eventProcessorHost;
}
async Task ITaskHub.StartAsync()
{
this.shutdownSource = new CancellationTokenSource();
// load the taskhub parameters
var jsonText = await this.taskhubParameters.DownloadTextAsync().ConfigureAwait(false);
this.parameters = JsonConvert.DeserializeObject <TaskhubParameters>(jsonText);
this.taskhubGuid = this.parameters.TaskhubGuid.ToByteArray();
// check that we are the correct taskhub!
if (this.parameters.TaskhubName != this.settings.HubName)
{
throw new InvalidOperationException($"The specified taskhub name does not match the task hub name in {this.taskhubParameters.Name}");
}
this.host.NumberPartitions = (uint)this.parameters.StartPositions.Length;
this.connections = new EventHubsConnections(this.settings.ResolvedTransportConnectionString, this.parameters.PartitionHubs, this.parameters.ClientHubs)
{
Host = host,
TraceHelper = this.traceHelper,
};
await this.connections.StartAsync(this.parameters.StartPositions.Length);
this.client = this.host.AddClient(this.ClientId, this.parameters.TaskhubGuid, this);
this.clientEventLoopTask = Task.Run(this.ClientEventLoop);
if (PartitionHubs.Length > 1)
{
throw new NotSupportedException("Using multiple eventhubs for partitions is not yet supported.");
}
if (this.client == null)
{
throw new InvalidOperationException("client must be started before partition hosting is started.");
}
string partitionsHub = PartitionHubs[0];
switch (this.settings.PartitionManagement)
{
case PartitionManagementOptions.EventProcessorHost:
{
this.traceHelper.LogInformation("Registering EventProcessorHost with EventHubs");
this.eventProcessorHost = new EventProcessorHost(
partitionsHub,
EventHubsTransport.PartitionConsumerGroup,
this.settings.ResolvedTransportConnectionString,
this.settings.ResolvedStorageConnectionString,
this.cloudBlobContainer.Name);
var processorOptions = new EventProcessorOptions()
{
InitialOffsetProvider = (s) => EventPosition.FromSequenceNumber(this.parameters.StartPositions[int.Parse(s)] - 1),
MaxBatchSize = 300,
PrefetchCount = 500,
};
await this.eventProcessorHost.RegisterEventProcessorFactoryAsync(this, processorOptions).ConfigureAwait(false);
break;
}
case PartitionManagementOptions.Scripted:
{
this.traceHelper.LogInformation($"Starting scripted partition host");
this.scriptedEventProcessorHost = new ScriptedEventProcessorHost(
partitionsHub,
EventHubsTransport.PartitionConsumerGroup,
this.settings.ResolvedTransportConnectionString,
this.settings.ResolvedStorageConnectionString,
this.cloudBlobContainer.Name,
this.host,
this,
this.connections,
this.parameters,
this.settings,
this.traceHelper,
this.settings.WorkerId);
var thread = new Thread(() => this.scriptedEventProcessorHost.StartEventProcessing(this.settings, this.partitionScript));
thread.Name = "ScriptedEventProcessorHost";
thread.Start();
break;
}
case PartitionManagementOptions.ClientOnly:
{
break;
}
}
}