org.apache.samza.system

Class IncomingMessageEnvelope

java.lang.Object

org.apache.samza.system.IncomingMessageEnvelope

public class IncomingMessageEnvelope
extends java.lang.Object

This class represents a message envelope that is received by a StreamTask for each message that is received from a partition of a specific input stream.

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	END_OF_STREAM_OFFSET

Constructor Summary

Constructors

Constructor and Description
IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition, java.lang.String offset, java.lang.Object key, java.lang.Object message) Constructs a new IncomingMessageEnvelope from specified components.
IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition, java.lang.String offset, java.lang.Object key, java.lang.Object message, int size) Constructs a new IncomingMessageEnvelope from specified components.
IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition, java.lang.String offset, java.lang.Object key, java.lang.Object message, int size, long eventTime, long arrivalTime) Constructs a new IncomingMessageEnvelope from specified components

Method Summary

Modifier and Type	Method and Description
static IncomingMessageEnvelope	buildDrainMessage(SystemStreamPartition ssp, java.lang.String runId)
static IncomingMessageEnvelope	buildEndOfStreamEnvelope(SystemStreamPartition ssp) This method is deprecated in favor of WatermarkManager.buildEndOfStreamEnvelope(SystemStreamPartition ssp).
static IncomingMessageEnvelope	buildWatermarkEnvelope(SystemStreamPartition ssp, long watermark)
boolean	equals(java.lang.Object obj)
long	getArrivalTime() Getter for arrival time
long	getEventTime() Getter for event time
java.lang.Object	getKey()
java.lang.Object	getMessage()
java.lang.String	getOffset() Offset associated with this message, provided by the system consumer that consumed the message.
int	getSize()
SystemStreamPartition	getSystemStreamPartition()
SystemStreamPartition	getSystemStreamPartition(int elasticityFactor) fetches the SSP (with keybucket) for the envelope based on elasticity factor.
int	hashCode()
boolean	isDrain()
boolean	isEndOfStream()
boolean	isWatermark()
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

END_OF_STREAM_OFFSET

public static final java.lang.String END_OF_STREAM_OFFSET

Constructor Detail

IncomingMessageEnvelope

public IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition,
                               java.lang.String offset,
                               java.lang.Object key,
                               java.lang.Object message)

Constructs a new IncomingMessageEnvelope from specified components.

Parameters:

systemStreamPartition - The aggregate object representing the incoming stream name, the name of the cluster from which the stream came, and the partition of the stream from which the message was received.

offset - offset associated with this message, provided by the system consumer that consumed the message

key - A deserialized key received from the partition offset.

message - A deserialized message received from the partition offset.

IncomingMessageEnvelope

public IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition,
                               java.lang.String offset,
                               java.lang.Object key,
                               java.lang.Object message,
                               int size)

Constructs a new IncomingMessageEnvelope from specified components.

Parameters:

systemStreamPartition - The aggregate object representing the incoming stream name, the name of the cluster from which the stream came, and the partition of the stream from which the message was received.

offset - offset associated with this message, provided by the system consumer that consumed the message

key - A deserialized key received from the partition offset.

message - A deserialized message received from the partition offset.

size - size of the message and key in bytes.

IncomingMessageEnvelope

public IncomingMessageEnvelope(SystemStreamPartition systemStreamPartition,
                               java.lang.String offset,
                               java.lang.Object key,
                               java.lang.Object message,
                               int size,
                               long eventTime,
                               long arrivalTime)

Constructs a new IncomingMessageEnvelope from specified components

Parameters:

systemStreamPartition - The aggregate object representing the incoming stream name, the name of the cluster from which the stream came, and the partition of the stream from which the message was received.

offset - offset associated with this message, provided by the system consumer that consumed the message

key - A deserialized key received from the partition offset.

message - A deserialized message received from the partition offset.

size - size of the message and key in bytes.

eventTime - the timestamp (in epochMillis) of when this event happened

arrivalTime - the timestamp (in epochMillis) of when this event arrived to (i.e., was picked-up by) Samza

Method Detail

getEventTime

public long getEventTime()

Getter for event time

Returns:

this.eventTime

getArrivalTime

public long getArrivalTime()

Getter for arrival time

Returns:

this.arrivalTime

getSystemStreamPartition

public SystemStreamPartition getSystemStreamPartition()

getSystemStreamPartition

public SystemStreamPartition getSystemStreamPartition(int elasticityFactor)

fetches the SSP (with keybucket) for the envelope based on elasticity factor. keyBucket is determined by the key if non-null else by the offset Special case messages like Watermark msgs which should belong to all keybuckets of an ssp however, they might have both key and offset as null, hence keybucket cant be determined but choosing keybucket = 0 as ssp with keybucket is expected with elasticity enabled the correct handling of special case messages is the responsibility of the caller

Parameters:

elasticityFactor -

Returns:

SSP without keybucket if elasticity is not enabled SSP with keybucket otherwise

getOffset

public java.lang.String getOffset()

Offset associated with this message, provided by the system consumer that consumed the message.

getKey

public java.lang.Object getKey()

getMessage

public java.lang.Object getMessage()

getSize

public int getSize()

isEndOfStream

public boolean isEndOfStream()

isDrain

public boolean isDrain()

isWatermark

public boolean isWatermark()

buildEndOfStreamEnvelope

public static IncomingMessageEnvelope buildEndOfStreamEnvelope(SystemStreamPartition ssp)

This method is deprecated in favor of WatermarkManager.buildEndOfStreamEnvelope(SystemStreamPartition ssp).

Parameters:

ssp - The SSP that is at end-of-stream.

Returns:

an IncomingMessageEnvelope corresponding to end-of-stream for that SSP.

buildDrainMessage

public static IncomingMessageEnvelope buildDrainMessage(SystemStreamPartition ssp,
                                                        java.lang.String runId)

buildWatermarkEnvelope

public static IncomingMessageEnvelope buildWatermarkEnvelope(SystemStreamPartition ssp,
                                                             long watermark)

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object