org.apache.cassandra.streaming.async

Class NettyStreamingMessageSender

java.lang.Object

org.apache.cassandra.streaming.async.NettyStreamingMessageSender

All Implemented Interfaces:

StreamingMessageSender

public class NettyStreamingMessageSender
extends java.lang.Object
implements StreamingMessageSender

Responsible for sending StreamMessages to a given peer. We manage an array of netty Channels for sending OutgoingStreamMessage instances; all other StreamMessage types are sent via a special control channel. The reason for this is to treat those messages carefully and not let them get stuck behind a stream transfer. One of the challenges when sending streams is we might need to delay shipping the stream if: - we've exceeded our network I/O use due to rate limiting (at the cassandra level) - the receiver isn't keeping up, which causes the local TCP socket buffer to not empty, which causes epoll writes to not move any bytes to the socket, which causes buffers to stick around in user-land (a/k/a cassandra) memory. When those conditions occur, it's easy enough to reschedule processing the stream once the resources pick up (we acquire the permits from the rate limiter, or the socket drains). However, we need to ensure that no other messages are submitted to the same channel while the current stream is still being processed.

Constructor Summary

Constructors

Constructor and Description
NettyStreamingMessageSender(StreamSession session, OutboundConnectionSettings template, StreamConnectionFactory factory, int streamingVersion, boolean isPreview)

Method Summary

Modifier and Type	Method and Description
void	close()
boolean	connected()
boolean	hasControlChannel()
void	initialize()
void	injectControlMessageChannel(io.netty.channel.Channel channel) Used by follower to setup control message channel created by initiator
void	sendMessage(StreamMessage message)
void	setClosed() For testing purposes only.

Methods inherited from class java.lang.Object

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

Constructor Detail

NettyStreamingMessageSender

public NettyStreamingMessageSender(StreamSession session,
                                   OutboundConnectionSettings template,
                                   StreamConnectionFactory factory,
                                   int streamingVersion,
                                   boolean isPreview)

Method Detail

initialize

public void initialize()

Specified by:

initialize in interface StreamingMessageSender

hasControlChannel

public boolean hasControlChannel()

injectControlMessageChannel

public void injectControlMessageChannel(io.netty.channel.Channel channel)

Used by follower to setup control message channel created by initiator

sendMessage

public void sendMessage(StreamMessage message)

Specified by:

sendMessage in interface StreamingMessageSender

setClosed

public void setClosed()

For testing purposes only.

connected

public boolean connected()

Specified by:

connected in interface StreamingMessageSender

close

public void close()

Specified by:

close in interface StreamingMessageSender