org.apache.drill.exec.rpc

Class AbstractRemoteConnection

java.lang.Object

org.apache.drill.exec.rpc.AbstractRemoteConnection

All Implemented Interfaces:

AutoCloseable, ConnectionThrottle, EncryptionContext, RemoteConnection

Direct Known Subclasses:

AbstractClientConnection, AbstractServerConnection

public abstract class AbstractRemoteConnection
extends Object
implements RemoteConnection, EncryptionContext

Field Summary

Fields

Modifier and Type	Field and Description
protected SaslCodec	saslCodec

Constructor Summary

Constructors

Constructor and Description
AbstractRemoteConnection(io.netty.channel.socket.SocketChannel channel, String name, EncryptionContext encryptionContext)

Method Summary

Modifier and Type	Method and Description
void	addSecurityHandlers() Helps to add all the required security handler's after negotiation for encryption is completed.
boolean	blockOnNotWritable(RpcOutcomeListener<?> listener)
void	channelClosed(RpcException ex) Called from the RpcBus's channel close handler to close all remaining resources associated with this connection.
void	close() Connection consumer wants to close connection.
<V> ChannelListenerWithCoordinationId	createNewRpcListener(RpcOutcomeListener<V> handler, Class<V> clazz) Create a new rpc listener that will be notified when the response is returned.
abstract void	decConnectionCounter()
<V> RpcOutcome<V>	getAndRemoveRpcOutcome(int rpcType, int coordinationId, Class<V> clazz) For incoming messages, remove the outcome listener and return it.
io.netty.channel.Channel	getChannel()
String	getEncryptionCtxtString()
int	getMaxWrappedSize()
String	getName()
SocketAddress	getRemoteAddress()
int	getWrapSizeLimit()
abstract void	incConnectionCounter()
boolean	inEventLoop()
boolean	isActive()
boolean	isEncryptionEnabled()
void	recordRemoteFailure(int coordinationId, UserBitShared.DrillPBError failure) Inform the local outcome listener that the remote operation could not be handled.
void	setAutoRead(boolean enableAutoRead)
void	setEncryption(boolean encrypted)
void	setMaxWrappedSize(int maxWrappedChunkSize)
void	setWrapSizeLimit(int wrapSizeLimit)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.drill.exec.rpc.RemoteConnection

getAllocator

Field Detail

saslCodec

protected SaslCodec saslCodec

Constructor Detail

AbstractRemoteConnection

public AbstractRemoteConnection(io.netty.channel.socket.SocketChannel channel,
                                String name,
                                EncryptionContext encryptionContext)

Method Detail

inEventLoop

public boolean inEventLoop()

Specified by:

inEventLoop in interface RemoteConnection

getName

public String getName()

Specified by:

getName in interface RemoteConnection

getChannel

public final io.netty.channel.Channel getChannel()

Specified by:

getChannel in interface RemoteConnection

blockOnNotWritable

public boolean blockOnNotWritable(RpcOutcomeListener<?> listener)

Specified by:

blockOnNotWritable in interface RemoteConnection

setAutoRead

public void setAutoRead(boolean enableAutoRead)

Specified by:

setAutoRead in interface ConnectionThrottle

isActive

public boolean isActive()

Specified by:

isActive in interface RemoteConnection

getAndRemoveRpcOutcome

public <V> RpcOutcome<V> getAndRemoveRpcOutcome(int rpcType,
                                                int coordinationId,
                                                Class<V> clazz)

For incoming messages, remove the outcome listener and return it. Can only be done once per coordinationId creation. CoordinationId's are recycled so they will show up once we run through all 4B of them.

Specified by:

getAndRemoveRpcOutcome in interface RemoteConnection

Parameters:

rpcType - The rpc type associated with the coordination.

coordinationId - The coordination id that was returned with the listener was created.

clazz - The class that is expected in response.

Returns:

An RpcOutcome associated with the provided coordinationId.

createNewRpcListener

public <V> ChannelListenerWithCoordinationId createNewRpcListener(RpcOutcomeListener<V> handler,
                                                                  Class<V> clazz)

Create a new rpc listener that will be notified when the response is returned.

Specified by:

createNewRpcListener in interface RemoteConnection

Parameters:

handler - The outcome handler to be notified when the response arrives.

clazz - The Class associated with the response object.

Returns:

The new listener. Also carries the coordination id for use in the rpc message.

recordRemoteFailure

public void recordRemoteFailure(int coordinationId,
                                UserBitShared.DrillPBError failure)

Inform the local outcome listener that the remote operation could not be handled.

Specified by:

recordRemoteFailure in interface RemoteConnection

Parameters:

coordinationId - The id that failed.

failure - The failure that occurred.

channelClosed

public void channelClosed(RpcException ex)

Called from the RpcBus's channel close handler to close all remaining resources associated with this connection. Ensures that any pending back-pressure items are also unblocked so they can be thrown away.

Specified by:

channelClosed in interface RemoteConnection

Parameters:

ex - The exception that caused the channel to close.

getRemoteAddress

public SocketAddress getRemoteAddress()

Specified by:

getRemoteAddress in interface RemoteConnection

close

public void close()

Connection consumer wants to close connection. Initiate connection close and complete. This is a blocking call that ensures that the connection is closed before returning. As part of this call, the channel close handler will be triggered which will call channelClosed() above. The latter will happen in a separate thread while this method is blocking.

The check for isActive is not required here since channel can be in OPEN state without being active. We want to close in both the scenarios. A channel is in OPEN state when a socket is created for it before binding to an address.

For connection oriented transport protocol channel moves to ACTIVE state when a connection is established using this channel. We need to have channel in ACTIVE state NOT OPEN before we can send any message to remote endpoint. For connectionless transport protocol a sender can send data as soon as channel moves to OPEN state.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface RemoteConnection

addSecurityHandlers

public void addSecurityHandlers()

Helps to add all the required security handler's after negotiation for encryption is completed.

Handler's before encryption is negotiated are:

• PROTOCOL_DECODER ProtobufLengthDecoder
• MESSAGE_DECODER RpcDecoder
• PROTOCOL_ENCODER RpcEncoder
• HANDSHAKE_HANDLER BasicClient.ClientHandshakeHandler OR BasicServer.ServerHandshakeHandler
• optional - IDLE_STATE_HANDLER org.apache.drill.exec.rpc.BasicClient.IdlePingHandler OR - TIMEOUT_HANDLER BasicServer.LoggingReadTimeoutHandler
• MESSAGE_HANDLER RpcBus.InboundHandler
• EXCEPTION_HANDLER RpcExceptionHandler

Handler's after encryption is negotiated are:

• LENGTH_DECODER_HANDLER LengthFieldBasedFrameDecoder
• SASL_DECRYPTION_HANDLER SaslDecryptionHandler
• PROTOCOL_DECODER ProtobufLengthDecoder
• MESSAGE_DECODER RpcDecoder
• SASL_ENCRYPTION_HANDLER SaslEncryptionHandler
• CHUNK_CREATION_HANDLER ChunkCreationHandler
• PROTOCOL_ENCODER RpcEncoder
• HANDSHAKE_HANDLER BasicClient.ClientHandshakeHandler OR BasicServer.ServerHandshakeHandler
• optional - IDLE_STATE_HANDLER org.apache.drill.exec.rpc.BasicClient.IdlePingHandler OR - TIMEOUT_HANDLER BasicServer.LoggingReadTimeoutHandler
• MESSAGE_HANDLER RpcBus.InboundHandler
• EXCEPTION_HANDLER RpcExceptionHandler

If encryption is enabled ChunkCreationHandler is always added to divide the Rpc message into chunks of negotiated EncryptionContextImpl.wrapSizeLimit bytes. This helps to make a generic encryption handler.

Specified by:

addSecurityHandlers in interface RemoteConnection

incConnectionCounter

public abstract void incConnectionCounter()

decConnectionCounter

public abstract void decConnectionCounter()

setEncryption

public void setEncryption(boolean encrypted)

Specified by:

setEncryption in interface EncryptionContext

isEncryptionEnabled

public boolean isEncryptionEnabled()

Specified by:

isEncryptionEnabled in interface EncryptionContext

getEncryptionCtxtString

public String getEncryptionCtxtString()

Specified by:

getEncryptionCtxtString in interface EncryptionContext

setMaxWrappedSize

public void setMaxWrappedSize(int maxWrappedChunkSize)

Specified by:

setMaxWrappedSize in interface EncryptionContext

getMaxWrappedSize

public int getMaxWrappedSize()

Specified by:

getMaxWrappedSize in interface EncryptionContext

setWrapSizeLimit

public void setWrapSizeLimit(int wrapSizeLimit)

Specified by:

setWrapSizeLimit in interface EncryptionContext

getWrapSizeLimit

public int getWrapSizeLimit()

Specified by:

getWrapSizeLimit in interface EncryptionContext