backtype.storm.messaging.netty

Class Client

java.lang.Object

backtype.storm.messaging.ConnectionWithStatus

backtype.storm.messaging.netty.Client

All Implemented Interfaces:

IConnection, IStatefulObject

public class Client
extends ConnectionWithStatus
implements IStatefulObject

A Netty client for sending task messages to a remote destination (Netty server). Implementation details: - Sending messages, i.e. writing to the channel, is performed asynchronously. - Messages are sent in batches to optimize for network throughput at the expense of network latency. The message batch size is configurable. - Connecting and reconnecting are performed asynchronously. - Note: The current implementation drops any messages that are being enqueued for sending if the connection to the remote destination is currently unavailable. - A background flusher thread is run in the background. It will, at fixed intervals, check for any pending messages (i.e. messages buffered in memory) and flush them to the remote destination iff background flushing is currently enabled.

Nested Class Summary

Nested classes/interfaces inherited from class backtype.storm.messaging.ConnectionWithStatus

ConnectionWithStatus.Status

Field Summary

Fields

Modifier and Type	Field and Description
protected String	dstAddressPrefixedName
protected Map	stormConf

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Gracefully close this client.
Object	getState()
Iterator<TaskMessage>	recv(int flags, int clientId) Receiving messages is not supported by a client.
void	send(int taskId, byte[] payload) send a message with taskId and payload
void	send(Iterator<TaskMessage> msgs) Enqueue task messages to be sent to the remote destination (cf.
ConnectionWithStatus.Status	status() Note: Storm will check via this method whether a worker can be activated safely during the initial startup of a topology.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

dstAddressPrefixedName

protected final String dstAddressPrefixedName

stormConf

protected final Map stormConf

Method Detail

status

public ConnectionWithStatus.Status status()

Note: Storm will check via this method whether a worker can be activated safely during the initial startup of a topology. The worker will only be activated once all of the its connections are ready.

Specified by:

status in class ConnectionWithStatus

recv

public Iterator<TaskMessage> recv(int flags,
                         int clientId)

Receiving messages is not supported by a client.

Specified by:

recv in interface IConnection

Parameters:

flags - 0: block, 1: non-block

Returns:

Throws:

UnsupportedOperationException - whenever this method is being called.

send

public void send(int taskId,
        byte[] payload)

Description copied from interface: IConnection

send a message with taskId and payload

Specified by:

send in interface IConnection

Parameters:

taskId - task ID

send

public void send(Iterator<TaskMessage> msgs)

Enqueue task messages to be sent to the remote destination (cf. `host` and `port`).

Specified by:

send in interface IConnection

close

public void close()

Gracefully close this client. We will attempt to send any pending messages (i.e. messages currently buffered in memory) before closing the client.

Specified by:

close in interface IConnection

getState

public Object getState()

Specified by:

getState in interface IStatefulObject

toString

public String toString()

Overrides:

toString in class Object