public override Task <ClientProto.StatusResponse> GetReady(ClientProto.BlockInfo blockInfo, ServerCallContext context)
{
ClientProto.StatusResponse response = new ClientProto.StatusResponse {
Type = ClientProto.StatusResponse.Types.StatusType.Success
};
if (blockInfo.IpAddress.Count() == 0)
{
response.Type = ClientProto.StatusResponse.Types.StatusType.Ready;
return(Task.FromResult(response));
}
else
{
Guid blockId = Guid.Parse(blockInfo.BlockId.Value);
Channel channel = null;
string ipAddress = "";
try
{
ipAddress = blockInfo.IpAddress[0];
blockInfo.IpAddress.RemoveAt(0);
channel = ConnectionManager.Instance.CreateChannel(blockId, ipAddress, Constants.Port.ToString());
var client = new ClientProto.ClientProto.ClientProtoClient(channel);
client.GetReady(blockInfo);
}
catch (RpcException e)
{
ConnectionManager.Instance.ShutDownChannel(blockId, channel);
response.Message = "Failed to get ready for " + ipAddress + ": " + e.Message;
}
// We will always return ready as if it reaches this far there is at least 1 node in the pipeline, which is good enough!
return(Task.FromResult(response));
}
}
/// <summary>
/// Server side handler of the WriteDataBlock RPC. DataNode writes block to a file and then returns success status of write.
/// </summary>
/// <param name="requestStream">Stream of bytes</param>
/// <param name="context">Context of call. Contains metadata containing blockid and list of addresses</param>
/// <returns>Status of task</returns>
public override async Task <ClientProto.StatusResponse> WriteBlock(Grpc.Core.IAsyncStreamReader <ClientProto.BlockData> requestStream, ServerCallContext context)
{
List <Metadata.Entry> metaData = context.RequestHeaders.ToList();
// Get blockID
Guid blockId = Util.GetBlockID(metaData);
int blockSize = Util.GetBlockSize(metaData);
string filePath = BlockStorage.Instance.CreateFile(blockId);
Channel channel = ConnectionManager.Instance.GetChannel(blockId);
ClientProto.StatusResponse response = new ClientProto.StatusResponse {
Type = ClientProto.StatusResponse.Types.StatusType.Success
};
// No channel found means last datanode in pipe
if (channel != null)
{
response = await WriteAndForwardBlock(requestStream, context, channel, filePath, blockId, blockSize);
}
else // Just write to file
{
response = await WriteBlock(requestStream, filePath, blockId, blockSize);
}
if (response.Type == ClientProto.StatusResponse.Types.StatusType.Success)
{
Console.WriteLine("Done writing block: " + blockId.ToString());
// Send block report to NameNode
var client = new DataNodeProto.DataNodeProto.DataNodeProtoClient(ConnectionManager.Instance.NameNodeConnection);
BlockReport.SendSingleBlockReport(client);
}
return(response);
}
/// <summary>
/// Writes block to disk and forwards to next DataNode
/// </summary>
/// <param name="requestStream">Stream of bytes</param>
/// <param name="context">Context of call</param>
/// <param name="channel">Channel for pipe</param>
/// <param name="filePath">Full path of file</param>
/// <param name="blockId">Unique identifier of block</param>
/// <returns>Status of writing the block</returns>
public async Task <ClientProto.StatusResponse> WriteAndForwardBlock(Grpc.Core.IAsyncStreamReader <ClientProto.BlockData> requestStream, ServerCallContext context, Channel channel, string filePath, Guid blockId, int blockSize)
{
bool success = true;
string message = "";
var client = new ClientProto.ClientProto.ClientProtoClient(channel);
using (var call = client.WriteBlock(context.RequestHeaders))
{
bool dataNodeFailed = false;
using (var stream = new FileStream(filePath, FileMode.Append, FileAccess.Write, FileShare.None, 131072, FileOptions.WriteThrough)) // 128KB
{
while (await requestStream.MoveNext())
{
try
{
var blockData = requestStream.Current;
byte[] data = blockData.Data.ToByteArray();
// Write to file
stream.Write(data, 0, data.Length);
// Don't need to forward data in pipe if datanode failed
if (!dataNodeFailed)
{
try
{
// Send data through pipe
await call.RequestStream.WriteAsync(blockData);
}
catch (RpcException e)
{
dataNodeFailed = true;
Console.WriteLine("Writing block failed: " + e.Message);
message = e.Message;
}
}
}
catch (IOException e)
{
dataNodeFailed = true;
message = e.Message;
success = false;
}
}
stream.Flush();
}
ClientProto.StatusResponse resp = new ClientProto.StatusResponse {
Type = ClientProto.StatusResponse.Types.StatusType.Fail, Message = message
};
// If DataNode did not fail, get response and shut down
if (!dataNodeFailed)
{
await call.RequestStream.CompleteAsync();
resp = await call.ResponseAsync;
ConnectionManager.Instance.ShutDownChannel(blockId, channel);
}
// If write was successful and block size is correct, return success
// Otherwise return the response sent down through pipe
return((success && BlockStorage.Instance.ValidateBlock(blockId, filePath, blockSize)) ? new ClientProto.StatusResponse {
Type = ClientProto.StatusResponse.Types.StatusType.Success
} : resp);
}
}
