org.apache.nifi.cluster.flow.impl

Class DataFlowDaoImpl

java.lang.Object

org.apache.nifi.cluster.flow.impl.DataFlowDaoImpl

All Implemented Interfaces:

DataFlowDao

public class DataFlowDaoImpl
extends Object
implements DataFlowDao

Implements the FlowDao interface. The implementation tracks the state of the dataflow by annotating the filename of the flow state file. Specifically, the implementation correlates PersistedFlowState states to filename extensions. The correlation is as follows:

• CURRENT maps to flow.xml
• STALE maps to flow.xml.stale
• UNKNOWN maps to flow.xml.unknown

Whenever the flow state changes, the flow state file's name is updated to denote its state. The implementation also provides for a restore directory that may be configured for higher availability. At instance creation, if the primary or restore directories have multiple flow state files, an exception is thrown. If the primary directory has a current flow state file, but the restore directory does not, then the primary flow state file is copied to the restore directory. If the restore directory has a current flow state file, but the primary directory does not, then the restore flow state file is copied to the primary directory. If both the primary and restore directories have a current flow state file and the files are different, then an exception is thrown. When the flow state file is saved, it is always saved first to the restore directory followed by a save to the primary directory. When the flow state file is loaded, a check is made to verify that the primary and restore flow state files are both current. If either is not current, then an exception is thrown. The primary flow state file is always read when the load method is called.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	DataFlowDaoImpl.ClusterMetadata

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	autoStart
static String	CLUSTER_INFO_FILENAME
static String	CONTROLLER_SERVICES_FILENAME
static String	FLOW_PACKAGE
static String	FLOW_XML_FILENAME
private String	generatedRootGroupId
private static org.slf4j.Logger	logger
private File	primaryDirectory
static String	REPORTING_TASKS_FILENAME
private File	restoreDirectory
static String	SNIPPETS_FILENAME
static String	STALE_EXT
static String	TEMPLATES_FILENAME
static String	UNKNOWN_EXT

Constructor Summary

Constructors

Constructor and Description
DataFlowDaoImpl(File primaryDirectory)
DataFlowDaoImpl(File primaryDirectory, File restoreDirectory, boolean autoStart)

Method Summary

Modifier and Type	Method and Description
private File	addStateFileExtension(File file, PersistedFlowState state)
private byte[]	calculateMd5(InputStream in)
private File	createNewFlowStateFile(File dir)
private Element	createTextElement(Document document, String elementName, String value)
private File	ensureSingleCurrentStateFile(File dir)
private byte[]	getEmptyFlowBytes()
private File	getExistingFlowStateFile(File dir)
private File	getFlowStateFile(File dir)
private File[]	getFlowStateFiles(File dir)
PersistedFlowState	getPersistedFlowState() Gets the state of the dataflow.
private PersistedFlowState	getPersistedFlowState(File file)
ClusterDataFlow	loadDataFlow() Loads the cluster's dataflow.
private ClusterDataFlow	parseDataFlow(File file)
private File	removeStateFileExtension(File file)
private void	renameFlowStateFile(File flowStateFile, PersistedFlowState newState)
void	saveDataFlow(ClusterDataFlow dataFlow) Saves the cluster's dataflow.
void	setPersistedFlowState(PersistedFlowState flowState) Sets the state of the dataflow.
private void	syncWithRestore(File primaryFile, File restoreFile)
private void	writeClusterMetadata(DataFlowDaoImpl.ClusterMetadata clusterMetadata, OutputStream os)
private void	writeDataFlow(File file, ClusterDataFlow clusterDataFlow)
private void	writeDataFlow(File file, ClusterDataFlow clusterDataFlow, DataFlowDaoImpl.ClusterMetadata clusterMetadata)
private void	writeTarEntry(org.apache.commons.compress.archivers.tar.TarArchiveOutputStream tarOut, String filename, byte[] bytes)

Methods inherited from class java.lang.Object

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

Field Detail

primaryDirectory

private final File primaryDirectory

restoreDirectory

private final File restoreDirectory

autoStart

private final boolean autoStart

generatedRootGroupId

private final String generatedRootGroupId

STALE_EXT

public static final String STALE_EXT

See Also:

Constant Field Values

UNKNOWN_EXT

public static final String UNKNOWN_EXT

See Also:

Constant Field Values

FLOW_PACKAGE

public static final String FLOW_PACKAGE

See Also:

Constant Field Values

FLOW_XML_FILENAME

public static final String FLOW_XML_FILENAME

See Also:

Constant Field Values

TEMPLATES_FILENAME

public static final String TEMPLATES_FILENAME

See Also:

Constant Field Values

SNIPPETS_FILENAME

public static final String SNIPPETS_FILENAME

See Also:

Constant Field Values

CONTROLLER_SERVICES_FILENAME

public static final String CONTROLLER_SERVICES_FILENAME

See Also:

Constant Field Values

REPORTING_TASKS_FILENAME

public static final String REPORTING_TASKS_FILENAME

See Also:

Constant Field Values

CLUSTER_INFO_FILENAME

public static final String CLUSTER_INFO_FILENAME

See Also:

Constant Field Values

logger

private static final org.slf4j.Logger logger

Constructor Detail

DataFlowDaoImpl

public DataFlowDaoImpl(File primaryDirectory)
                throws DaoException

Throws:

DaoException

DataFlowDaoImpl

public DataFlowDaoImpl(File primaryDirectory,
                       File restoreDirectory,
                       boolean autoStart)
                throws DaoException

Throws:

DaoException

Method Detail

syncWithRestore

private void syncWithRestore(File primaryFile,
                             File restoreFile)
                      throws IOException

Throws:

IOException

calculateMd5

private byte[] calculateMd5(InputStream in)
                     throws IOException

Throws:

IOException

loadDataFlow

public ClusterDataFlow loadDataFlow()
                             throws DaoException

Description copied from interface: DataFlowDao

Loads the cluster's dataflow.

Specified by:

loadDataFlow in interface DataFlowDao

Returns:

the dataflow or null if no dataflow exists

Throws:

DaoException - if the dataflow was unable to be loaded

saveDataFlow

public void saveDataFlow(ClusterDataFlow dataFlow)
                  throws DaoException

Description copied from interface: DataFlowDao

Saves the cluster's dataflow.

Specified by:

saveDataFlow in interface DataFlowDao

Parameters:

dataFlow - flow

Throws:

DaoException - if the dataflow was unable to be saved

getPersistedFlowState

public PersistedFlowState getPersistedFlowState()

Description copied from interface: DataFlowDao

Gets the state of the dataflow.

Specified by:

getPersistedFlowState in interface DataFlowDao

Returns:

the state of the dataflow

setPersistedFlowState

public void setPersistedFlowState(PersistedFlowState flowState)
                           throws DaoException

Description copied from interface: DataFlowDao

Sets the state of the dataflow. If the dataflow does not exist, then an exception is thrown.

Specified by:

setPersistedFlowState in interface DataFlowDao

Parameters:

flowState - the state of the dataflow

Throws:

DaoException - if the state was unable to be updated

ensureSingleCurrentStateFile

private File ensureSingleCurrentStateFile(File dir)
                                   throws IOException,
                                          JAXBException

Throws:

IOException

JAXBException

getPersistedFlowState

private PersistedFlowState getPersistedFlowState(File file)

getFlowStateFile

private File getFlowStateFile(File dir)

getExistingFlowStateFile

private File getExistingFlowStateFile(File dir)

getFlowStateFiles

private File[] getFlowStateFiles(File dir)

removeStateFileExtension

private File removeStateFileExtension(File file)

addStateFileExtension

private File addStateFileExtension(File file,
                                   PersistedFlowState state)

createNewFlowStateFile

private File createNewFlowStateFile(File dir)
                             throws IOException,
                                    JAXBException

Throws:

IOException

JAXBException

getEmptyFlowBytes

private byte[] getEmptyFlowBytes()
                          throws IOException

Throws:

IOException

createTextElement

private Element createTextElement(Document document,
                                  String elementName,
                                  String value)

renameFlowStateFile

private void renameFlowStateFile(File flowStateFile,
                                 PersistedFlowState newState)
                          throws DaoException

Throws:

DaoException

parseDataFlow

private ClusterDataFlow parseDataFlow(File file)
                               throws IOException,
                                      JAXBException,
                                      DaoException

Throws:

IOException

JAXBException

DaoException

writeDataFlow

private void writeDataFlow(File file,
                           ClusterDataFlow clusterDataFlow)
                    throws IOException,
                           JAXBException

Throws:

IOException

JAXBException

writeTarEntry

private void writeTarEntry(org.apache.commons.compress.archivers.tar.TarArchiveOutputStream tarOut,
                           String filename,
                           byte[] bytes)
                    throws IOException

Throws:

IOException

writeDataFlow

private void writeDataFlow(File file,
                           ClusterDataFlow clusterDataFlow,
                           DataFlowDaoImpl.ClusterMetadata clusterMetadata)
                    throws IOException,
                           JAXBException

Throws:

IOException

JAXBException

writeClusterMetadata

private void writeClusterMetadata(DataFlowDaoImpl.ClusterMetadata clusterMetadata,
                                  OutputStream os)
                           throws IOException,
                                  JAXBException

Throws:

IOException

JAXBException