org.apache.nifi.processors.standard

Class Wait

java.lang.Object

org.apache.nifi.components.AbstractConfigurableComponent

org.apache.nifi.processor.AbstractSessionFactoryProcessor

org.apache.nifi.processor.AbstractProcessor

org.apache.nifi.processors.standard.Wait

All Implemented Interfaces:

ConfigurableComponent, Processor

@EventDriven
 @SupportsBatching
 @Tags(value={"map","cache","wait","hold","distributed","signal","release"})
 @InputRequirement(value=INPUT_REQUIRED)
 @CapabilityDescription(value="Routes incoming FlowFiles to the \'wait\' relationship until a matching release signal is stored in the distributed cache from a corresponding Notify processor. When a matching release signal is identified, a waiting FlowFile is routed to the \'success\' relationship, with attributes copied from the FlowFile that produced the release signal from the Notify processor.  The release signal entry is then removed from the cache. Waiting FlowFiles will be routed to \'expired\' if they exceed the Expiration Duration. If you need to wait for more than one signal, specify the desired number of signals via the \'Target Signal Count\' property. This is particularly useful with processors that split a source FlowFile into multiple fragments, such as SplitText. In order to wait for all fragments to be processed, connect the \'original\' relationship to a Wait processor, and the \'splits\' relationship to a corresponding Notify processor. Configure the Notify and Wait processors to use the \'${fragment.identifier}\' as the value of \'Release Signal Identifier\', and specify \'${fragment.count}\' as the value of \'Target Signal Count\' in the Wait processor.")
 @WritesAttribute(attribute="wait.start.timestamp",description="All FlowFiles will have an attribute \'wait.start.timestamp\', which sets the initial epoch timestamp when the file first entered this processor.  This is used to determine the expiration time of the FlowFile.") @WritesAttribute(attribute="wait.counter.<counterName>",description="If a signal exists when the processor runs, each count value in the signal is copied.")
 @SeeAlso(classNames={"org.apache.nifi.distributed.cache.client.DistributedMapCacheClientService","org.apache.nifi.distributed.cache.server.map.DistributedMapCacheServer","org.apache.nifi.processors.standard.Notify"})
public class Wait
extends AbstractProcessor

Field Summary

Fields

Modifier and Type	Field and Description
static AllowableValue	ATTRIBUTE_COPY_KEEP_ORIGINAL
static PropertyDescriptor	ATTRIBUTE_COPY_MODE
static AllowableValue	ATTRIBUTE_COPY_REPLACE
static PropertyDescriptor	DISTRIBUTED_CACHE_SERVICE
static PropertyDescriptor	EXPIRATION_DURATION
static Relationship	REL_EXPIRED
static Relationship	REL_FAILURE
static Relationship	REL_SUCCESS
static Relationship	REL_WAIT
static PropertyDescriptor	RELEASABLE_FLOWFILE_COUNT
static PropertyDescriptor	RELEASE_SIGNAL_IDENTIFIER
static PropertyDescriptor	SIGNAL_COUNTER_NAME
static PropertyDescriptor	TARGET_SIGNAL_COUNT
static PropertyDescriptor	WAIT_BUFFER_COUNT
static PropertyDescriptor	WAIT_MODE
static AllowableValue	WAIT_MODE_KEEP_IN_UPSTREAM
static AllowableValue	WAIT_MODE_TRANSFER_TO_WAIT
static java.lang.String	WAIT_START_TIMESTAMP

Constructor Summary

Constructors

Constructor and Description
Wait()

Method Summary

Modifier and Type	Method and Description
java.util.Set<Relationship>	getRelationships()
protected java.util.List<PropertyDescriptor>	getSupportedPropertyDescriptors() Allows subclasses to register which property descriptor objects are supported.
void	onTrigger(ProcessContext context, ProcessSession session)

Methods inherited from class org.apache.nifi.processor.AbstractProcessor

onTrigger

Methods inherited from class org.apache.nifi.processor.AbstractSessionFactoryProcessor

getControllerServiceLookup, getIdentifier, getLogger, getNodeTypeProvider, init, initialize, isConfigurationRestored, isScheduled, toString, updateConfiguredRestoredTrue, updateScheduledFalse, updateScheduledTrue

Methods inherited from class org.apache.nifi.components.AbstractConfigurableComponent

customValidate, equals, getPropertyDescriptor, getPropertyDescriptors, getSupportedDynamicPropertyDescriptor, hashCode, onPropertyModified, validate

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.nifi.components.ConfigurableComponent

getPropertyDescriptor, getPropertyDescriptors, onPropertyModified, validate

Field Detail

WAIT_START_TIMESTAMP

public static final java.lang.String WAIT_START_TIMESTAMP

See Also:

Constant Field Values

DISTRIBUTED_CACHE_SERVICE

public static final PropertyDescriptor DISTRIBUTED_CACHE_SERVICE

RELEASE_SIGNAL_IDENTIFIER

public static final PropertyDescriptor RELEASE_SIGNAL_IDENTIFIER

TARGET_SIGNAL_COUNT

public static final PropertyDescriptor TARGET_SIGNAL_COUNT

SIGNAL_COUNTER_NAME

public static final PropertyDescriptor SIGNAL_COUNTER_NAME

WAIT_BUFFER_COUNT

public static final PropertyDescriptor WAIT_BUFFER_COUNT

RELEASABLE_FLOWFILE_COUNT

public static final PropertyDescriptor RELEASABLE_FLOWFILE_COUNT

EXPIRATION_DURATION

public static final PropertyDescriptor EXPIRATION_DURATION

ATTRIBUTE_COPY_REPLACE

public static final AllowableValue ATTRIBUTE_COPY_REPLACE

ATTRIBUTE_COPY_KEEP_ORIGINAL

public static final AllowableValue ATTRIBUTE_COPY_KEEP_ORIGINAL

ATTRIBUTE_COPY_MODE

public static final PropertyDescriptor ATTRIBUTE_COPY_MODE

WAIT_MODE_TRANSFER_TO_WAIT

public static final AllowableValue WAIT_MODE_TRANSFER_TO_WAIT

WAIT_MODE_KEEP_IN_UPSTREAM

public static final AllowableValue WAIT_MODE_KEEP_IN_UPSTREAM

WAIT_MODE

public static final PropertyDescriptor WAIT_MODE

REL_SUCCESS

public static final Relationship REL_SUCCESS

REL_FAILURE

public static final Relationship REL_FAILURE

REL_WAIT

public static final Relationship REL_WAIT

REL_EXPIRED

public static final Relationship REL_EXPIRED

Constructor Detail

Wait

public Wait()

Method Detail

getSupportedPropertyDescriptors

protected java.util.List<PropertyDescriptor> getSupportedPropertyDescriptors()

Description copied from class: AbstractConfigurableComponent

Allows subclasses to register which property descriptor objects are supported. Default return is an empty set.

Overrides:

getSupportedPropertyDescriptors in class AbstractConfigurableComponent

Returns:

PropertyDescriptor objects this processor currently supports

getRelationships

public java.util.Set<Relationship> getRelationships()

Specified by:

getRelationships in interface Processor

Overrides:

getRelationships in class AbstractSessionFactoryProcessor

Returns:

Set of all relationships this processor expects to transfer a flow file to. An empty set indicates this processor does not have any destination relationships. Guaranteed non null.

onTrigger

public void onTrigger(ProcessContext context,
                      ProcessSession session)
               throws ProcessException

Specified by:

onTrigger in class AbstractProcessor

Throws:

ProcessException