org.apache.samza.system

Class StreamSpec

java.lang.Object

org.apache.samza.system.StreamSpec

public class StreamSpec
extends java.lang.Object

StreamSpec is a blueprint for creating, validating, or simply describing a stream in the runtime environment. It has specific attributes for common behaviors that Samza uses. It also includes a map of configurations which may be system-specific. It is immutable by design.

Constructor Summary

Constructors

Constructor and Description
StreamSpec(java.lang.String id, java.lang.String physicalName, java.lang.String systemName)
StreamSpec(java.lang.String id, java.lang.String physicalName, java.lang.String systemName, boolean isBounded, java.util.Map<java.lang.String,java.lang.String> config)
StreamSpec(java.lang.String id, java.lang.String physicalName, java.lang.String systemName, int partitionCount)
StreamSpec(java.lang.String id, java.lang.String physicalName, java.lang.String systemName, int partitionCount, boolean isBounded, java.util.Map<java.lang.String,java.lang.String> config)

Method Summary

Modifier and Type	Method and Description
StreamSpec	copyWithPartitionCount(int partitionCount) Copies this StreamSpec, but applies a new partitionCount.
StreamSpec	copyWithPhysicalName(java.lang.String physicalName)
static StreamSpec	createChangeLogStreamSpec(java.lang.String physicalName, java.lang.String systemName, int partitionCount)
static StreamSpec	createCheckpointStreamSpec(java.lang.String physicalName, java.lang.String systemName)
static StreamSpec	createCoordinatorStreamSpec(java.lang.String physicalName, java.lang.String systemName)
boolean	equals(java.lang.Object o)
java.lang.String	get(java.lang.String propertyName)
java.util.Map<java.lang.String,java.lang.String>	getConfig()
java.lang.String	getId()
java.lang.String	getOrDefault(java.lang.String propertyName, java.lang.String defaultValue)
int	getPartitionCount()
java.lang.String	getPhysicalName()
java.lang.String	getSystemName()
int	hashCode()
boolean	isBounded()
boolean	isChangeLogStream()
boolean	isCoordinatorStream()
java.lang.String	toString()
SystemStream	toSystemStream()

Methods inherited from class java.lang.Object

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

Constructor Detail

StreamSpec

public StreamSpec(java.lang.String id,
                  java.lang.String physicalName,
                  java.lang.String systemName)

Parameters:

id - The application-unique logical identifier for the stream. It is used to distinguish between streams in a Samza application so it must be unique in the context of one deployable unit. It does not need to be globally unique or unique with respect to a host.

physicalName - The physical identifier for the stream. This is the identifier that will be used in remote systems to identify the stream. In Kafka this would be the topic name whereas in HDFS it might be a file URN.

systemName - The System name on which this stream will exist. Corresponds to a named implementation of the Samza System abstraction. See SystemFactory

StreamSpec

public StreamSpec(java.lang.String id,
                  java.lang.String physicalName,
                  java.lang.String systemName,
                  int partitionCount)

Parameters:

id - The application-unique logical identifier for the stream. It is used to distinguish between streams in a Samza application so it must be unique in the context of one deployable unit. It does not need to be globally unique or unique with respect to a host.

physicalName - The physical identifier for the stream. This is the identifier that will be used in remote systems to identify the stream. In Kafka this would be the topic name whereas in HDFS it might be a file URN.

systemName - The System name on which this stream will exist. Corresponds to a named implementation of the Samza System abstraction. See SystemFactory

partitionCount - The number of partitionts for the stream. A value of 1 indicates unpartitioned.

StreamSpec

public StreamSpec(java.lang.String id,
                  java.lang.String physicalName,
                  java.lang.String systemName,
                  boolean isBounded,
                  java.util.Map<java.lang.String,java.lang.String> config)

Parameters:

id - The application-unique logical identifier for the stream. It is used to distinguish between streams in a Samza application so it must be unique in the context of one deployable unit. It does not need to be globally unique or unique with respect to a host.

physicalName - The physical identifier for the stream. This is the identifier that will be used in remote systems to identify the stream. In Kafka this would be the topic name whereas in HDFS it might be a file URN.

systemName - The System name on which this stream will exist. Corresponds to a named implementation of the Samza System abstraction. See SystemFactory

isBounded - The stream is bounded or not.

config - A map of properties for the stream. These may be System-specfic.

StreamSpec

public StreamSpec(java.lang.String id,
                  java.lang.String physicalName,
                  java.lang.String systemName,
                  int partitionCount,
                  boolean isBounded,
                  java.util.Map<java.lang.String,java.lang.String> config)

Parameters:

id - The application-unique logical identifier for the stream. It is used to distinguish between streams in a Samza application so it must be unique in the context of one deployable unit. It does not need to be globally unique or unique with respect to a host.

physicalName - The physical identifier for the stream. This is the identifier that will be used in remote systems to identify the stream. In Kafka this would be the topic name whereas in HDFS it might be a file URN.

systemName - The System name on which this stream will exist. Corresponds to a named implementation of the Samza System abstraction. See SystemFactory

partitionCount - The number of partitionts for the stream. A value of 1 indicates unpartitioned.

isBounded - The stream is bounded or not.

config - A map of properties for the stream. These may be System-specfic.

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

copyWithPartitionCount

public StreamSpec copyWithPartitionCount(int partitionCount)

Copies this StreamSpec, but applies a new partitionCount. This method is not static s.t. subclasses can override it.

Parameters:

partitionCount - The partitionCount for the returned StreamSpec.

Returns:

A copy of this StreamSpec with the specified partitionCount.

copyWithPhysicalName

public StreamSpec copyWithPhysicalName(java.lang.String physicalName)

getId

public java.lang.String getId()

getSystemName

public java.lang.String getSystemName()

getPhysicalName

public java.lang.String getPhysicalName()

getPartitionCount

public int getPartitionCount()

getConfig

public java.util.Map<java.lang.String,java.lang.String> getConfig()

get

public java.lang.String get(java.lang.String propertyName)

getOrDefault

public java.lang.String getOrDefault(java.lang.String propertyName,
                                     java.lang.String defaultValue)

toSystemStream

public SystemStream toSystemStream()

isChangeLogStream

public boolean isChangeLogStream()

isCoordinatorStream

public boolean isCoordinatorStream()

isBounded

public boolean isBounded()

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

createChangeLogStreamSpec

public static StreamSpec createChangeLogStreamSpec(java.lang.String physicalName,
                                                   java.lang.String systemName,
                                                   int partitionCount)

createCoordinatorStreamSpec

public static StreamSpec createCoordinatorStreamSpec(java.lang.String physicalName,
                                                     java.lang.String systemName)

createCheckpointStreamSpec

public static StreamSpec createCheckpointStreamSpec(java.lang.String physicalName,
                                                    java.lang.String systemName)