org.gridgain.grid.spi.swapspace.file

Class GridFileSwapSpaceSpi

java.lang.Object

org.gridgain.grid.spi.GridSpiAdapter

org.gridgain.grid.spi.swapspace.file.GridFileSwapSpaceSpi

All Implemented Interfaces:

GridSpi, GridSpiManagementMBean, GridFileSwapSpaceSpiMBean, GridSwapSpaceSpi

@GridSpiMultipleInstancesSupport(value=true)
public class GridFileSwapSpaceSpi
extends GridSpiAdapter
implements GridSwapSpaceSpi, GridFileSwapSpaceSpiMBean

File-based swap space SPI implementation which holds keys in memory. This SPI is used by default. It is intended for use in cases when value size is bigger than 100 bytes, otherwise it will not have any positive effect.

NOTE: This SPI does not support swap eviction currently, manual removes needed to reduce disk space consumption.

Every space has a name and when used in combination with in-memory data grid name and local node ID, space name represents the actual cache name associated with this swap space. Default name is null which is represented by DFLT_SPACE_NAME.

Configuration

Mandatory

This SPI has no mandatory configuration parameters.

Optional SPI configuration.

• Base directory path (see setBaseDirectory(String)).
• Maximum sparsity (see setMaximumSparsity(float)).
• Write buffer size in bytes (see setWriteBufferSize(int)).
• Max write queue size in bytes (see setMaxWriteQueueSize(int)).
• Read stripes number. (see setReadStripesNumber(int)).

Java Example

GridFileSwapSpaceSpi is configured by default and should be explicitly configured only if some SPI configuration parameters need to be overridden.

 GridFileSwapSpaceSpi spi = new GridFileSwapSpaceSpi();

 // Configure root folder path.
 spi.setBaseDirectory("/path/to/swap/folder");

 GridConfiguration cfg = new GridConfiguration();

 // Override default swap space SPI.
 cfg.setSwapSpaceSpi(spi);

 // Starts grid.
 G.start(cfg);
 

Spring Example

GridFileSwapSpaceSpi can be configured from Spring XML configuration file:

 <bean id="grid.cfg" class="org.gridgain.grid.GridConfiguration" scope="singleton">
     ...
     <property name="swapSpaceSpi">
         <bean class="org.gridgain.grid.spi.swapspace.file.GridFileSwapSpaceSpi">
             <property name="baseDirectory" value="/path/to/swap/folder"/>
         </bean>
     </property>
     ...
 </bean>
 

For information about Spring framework visit www.springframework.org

See Also:

GridSwapSpaceSpi

Field Summary

Fields

Modifier and Type	Field and Description
static String	DFLT_BASE_DIR Default base directory.
static int	DFLT_BUF_SIZE Default write buffer size in bytes.
static float	DFLT_MAX_SPARSITY Default maximum sparsity.
static int	DFLT_QUE_SIZE Default write queue size in bytes.
static String	DFLT_SPACE_NAME Name for null space.

Constructor Summary

Constructors

Constructor and Description
GridFileSwapSpaceSpi()

Method Summary

Methods

Modifier and Type	Method and Description
void	clear(String spaceName) Entirely clears data space with given name, if any.
long	count(String spaceName) Gets number of stored entries (keys) in data space with given name.
String	getBaseDirectory() Gets base directory.
float	getMaximumSparsity() Gets maximum sparsity.
int	getMaxWriteQueueSize() Gets max write queue size in bytes.
int	getReadStripesNumber() Gets read pool size.
int	getWriteBufferSize() Gets write buffer size in bytes.
<K> GridSpiCloseableIterator<K>	keyIterator(String spaceName, GridSwapContext ctx) Gets iterator over space keys.
Collection<Integer>	partitions(String spaceName) Gets partitions IDs that are stored in the passed in space.
GridSpiCloseableIterator<Map.Entry<byte[],byte[]>>	rawIterator(String spaceName) Gets raw iterator over space entries.
GridSpiCloseableIterator<Map.Entry<byte[],byte[]>>	rawIterator(String spaceName, int part) Gets raw iterator over space entries.
byte[]	read(String spaceName, GridSwapKey key, GridSwapContext ctx) Reads stored value as array of bytes by key from data space with given name.
Map<GridSwapKey,byte[]>	readAll(String spaceName, Iterable<GridSwapKey> keys, GridSwapContext ctx) Reads stored values as array of bytes by all passed keys from data space with given name.
void	remove(String spaceName, GridSwapKey key, GridInClosure<byte[]> c, GridSwapContext ctx) Removes value stored in data space with given name corresponding to specified key.
void	removeAll(String spaceName, Collection<GridSwapKey> keys, GridBiInClosure<GridSwapKey,byte[]> c, GridSwapContext ctx) Removes values stored in data space with given name corresponding to specified keys.
void	setBaseDirectory(String baseDir) Sets base directory.
void	setListener(GridSwapSpaceSpiListener evictLsnr) Sets eviction listener to receive notifications on evicted swap entries.
void	setMaximumSparsity(float maxSparsity) Sets maximum sparsity.
void	setMaxWriteQueueSize(int maxWriteQueSize) Sets max write queue size in bytes.
void	setReadStripesNumber(int readStripesNum) Sets read stripe size.
void	setWriteBufferSize(int writeBufSize) Sets write buffer size in bytes.
long	size(String spaceName) Gets size in bytes for data space with given name.
void	spiStart(String gridName) This method is called to start SPI.
void	spiStop() This method is called to stop SPI.
void	store(String spaceName, GridSwapKey key, byte[] val, GridSwapContext ctx) Stores value as array of bytes with given key into data space with given name.
void	storeAll(String spaceName, Map<GridSwapKey,byte[]> pairs, GridSwapContext ctx) Stores key-value pairs (both keys and values are arrays of bytes) into data space with given name.
String	toString()

Methods inherited from class org.gridgain.grid.spi.GridSpiAdapter

assertParameter, checkConfigurationConsistency0, configInfo, createSpiAttributeName, getConsistentAttributeNames, getGridGainHome, getLocalNodeId, getName, getNodeAttributes, getSpiContext, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted, injectables, onContextDestroyed, onContextDestroyed0, onContextInitialized, onContextInitialized0, registerMBean, setName, startInfo, startStopwatch, stopInfo, unregisterMBean

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.gridgain.grid.spi.GridSpi

getName, getNodeAttributes, onContextDestroyed, onContextInitialized

Methods inherited from interface org.gridgain.grid.spi.GridSpiManagementMBean

getGridGainHome, getLocalNodeId, getName, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted

Field Detail

DFLT_BASE_DIR

public static final String DFLT_BASE_DIR

Default base directory. Note that this path is relative to GRIDGAIN_HOME/work folder if GRIDGAIN_HOME system or environment variable specified, otherwise it is relative to work folder under system java.io.tmpdir folder.

See Also:

GridConfiguration.getWorkDirectory(), Constant Field Values

DFLT_MAX_SPARSITY

public static final float DFLT_MAX_SPARSITY

Default maximum sparsity.

See Also:

Constant Field Values

DFLT_BUF_SIZE

public static final int DFLT_BUF_SIZE

Default write buffer size in bytes.

See Also:

Constant Field Values

DFLT_QUE_SIZE

public static final int DFLT_QUE_SIZE

Default write queue size in bytes.

See Also:

Constant Field Values

DFLT_SPACE_NAME

public static final String DFLT_SPACE_NAME

Name for null space.

See Also:

Constant Field Values

Constructor Detail

GridFileSwapSpaceSpi

public GridFileSwapSpaceSpi()

Method Detail

getBaseDirectory

public String getBaseDirectory()

Gets base directory.

Specified by:

getBaseDirectory in interface GridFileSwapSpaceSpiMBean

Returns:

Base directory.

setBaseDirectory

@GridSpiConfiguration(optional=true)
public void setBaseDirectory(String baseDir)

Sets base directory.

Parameters:

baseDir - Base directory.

getMaximumSparsity

public float getMaximumSparsity()

Gets maximum sparsity.

Specified by:

getMaximumSparsity in interface GridFileSwapSpaceSpiMBean

Returns:

Maximum sparsity.

setMaximumSparsity

public void setMaximumSparsity(float maxSparsity)

Sets maximum sparsity. This property defines maximum acceptable wasted file space to whole file size ratio. When this ratio becomes higher than specified number compacting thread starts working.

Parameters:

maxSparsity - Maximum sparsity. Must be between 0 and 1, default is DFLT_MAX_SPARSITY.

getWriteBufferSize

public int getWriteBufferSize()

Gets write buffer size in bytes.

Specified by:

getWriteBufferSize in interface GridFileSwapSpaceSpiMBean

Returns:

Write buffer size in bytes.

setWriteBufferSize

public void setWriteBufferSize(int writeBufSize)

Sets write buffer size in bytes. Write to disk occurs only when this buffer is full. Default is DFLT_BUF_SIZE.

Parameters:

writeBufSize - Write buffer size in bytes.

getMaxWriteQueueSize

public int getMaxWriteQueueSize()

Gets max write queue size in bytes.

Specified by:

getMaxWriteQueueSize in interface GridFileSwapSpaceSpiMBean

Returns:

Max write queue size in bytes.

setMaxWriteQueueSize

public void setMaxWriteQueueSize(int maxWriteQueSize)

Sets max write queue size in bytes. If there are more values are waiting for being written to disk then specified size, SPI will block on store(String, GridSwapKey, byte[], GridSwapContext) operation. Default is DFLT_QUE_SIZE.

Parameters:

maxWriteQueSize - Max write queue size in bytes.

getReadStripesNumber

public int getReadStripesNumber()

Gets read pool size.

Specified by:

getReadStripesNumber in interface GridFileSwapSpaceSpiMBean

Returns:

Read pool size.

setReadStripesNumber

public void setReadStripesNumber(int readStripesNum)

Sets read stripe size. Defines number of file channels to be used concurrently. Default is equal to number of CPU cores available to this JVM.

Parameters:

readStripesNum - Read stripe number.

spiStart

public void spiStart(@Nullable
            String gridName)
              throws GridSpiException

This method is called to start SPI. After this method returns successfully kernel assumes that SPI is fully operational.

Specified by:

spiStart in interface GridSpi

Parameters:

gridName - Name of grid instance this SPI is being started for (null for default grid).

Throws:

GridSpiException - Throws in case of any error during SPI start.

spiStop

public void spiStop()
             throws GridSpiException

This method is called to stop SPI. After this method returns kernel assumes that this SPI is finished and all resources acquired by it are released.

Note that this method can be called at any point including during recovery of failed start. It should make no assumptions on what state SPI will be in when this method is called.

Specified by:

spiStop in interface GridSpi

Throws:

GridSpiException - Thrown in case of any error during SPI stop.

clear

public void clear(@Nullable
         String spaceName)
           throws GridSpiException

Entirely clears data space with given name, if any.

Specified by:

clear in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to clear.

Throws:

GridSpiException - In case of any errors.

size

public long size(@Nullable
        String spaceName)
          throws GridSpiException

Gets size in bytes for data space with given name. If specified space does not exist this method returns 0.

Specified by:

size in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to get size for.

Returns:

Size in bytes.

Throws:

GridSpiException - In case of any errors.

count

public long count(@Nullable
         String spaceName)
           throws GridSpiException

Gets number of stored entries (keys) in data space with given name. If specified space does not exist this method returns 0.

Specified by:

count in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to get number of entries for.

Returns:

Number of stored entries in specified space.

Throws:

GridSpiException - In case of any errors.

read

@Nullable
public byte[] read(@Nullable
                   String spaceName,
                   GridSwapKey key,
                   GridSwapContext ctx)
            throws GridSpiException

Reads stored value as array of bytes by key from data space with given name. If specified space does not exist this method returns null.

Specified by:

read in interface GridSwapSpaceSpi

Parameters:

spaceName - Name of the data space to read from.

key - Key used to read value from data space.

ctx - Swap context.

Returns:

Value as array of bytes stored in specified data space that matches to given key.

Throws:

GridSpiException - In case of any errors.

readAll

public Map<GridSwapKey,byte[]> readAll(@Nullable
                              String spaceName,
                              Iterable<GridSwapKey> keys,
                              GridSwapContext ctx)
                                throws GridSpiException

Reads stored values as array of bytes by all passed keys from data space with given name. If specified space does not exist this method returns empty map.

Specified by:

readAll in interface GridSwapSpaceSpi

Parameters:

spaceName - Name of the data space to read from.

keys - Keys used to read values from data space.

ctx - Swap context.

Returns:

Map in which keys are the ones passed into method and values are corresponding values read from swap storage.

Throws:

GridSpiException - In case of any errors.

remove

public void remove(@Nullable
          String spaceName,
          GridSwapKey key,
          @Nullable
          GridInClosure<byte[]> c,
          GridSwapContext ctx)
            throws GridSpiException

Removes value stored in data space with given name corresponding to specified key.

Specified by:

remove in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to remove value from.

key - Key to remove value in the specified space for.

c - Optional closure that takes removed value and executes after actual removing. If there was no value in storage the closure is not executed.

ctx - Swap context.

Throws:

GridSpiException - In case of any errors.

removeAll

public void removeAll(@Nullable
             String spaceName,
             Collection<GridSwapKey> keys,
             @Nullable
             GridBiInClosure<GridSwapKey,byte[]> c,
             GridSwapContext ctx)
               throws GridSpiException

Removes values stored in data space with given name corresponding to specified keys.

Specified by:

removeAll in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to remove values from.

keys - Keys to remove value in the specified space for.

c - Optional closure that takes removed value and executes after actual removing. If there was no value in storage the closure is not executed.

ctx - Swap context.

Throws:

GridSpiException - In case of any errors.

store

public void store(@Nullable
         String spaceName,
         GridSwapKey key,
         @Nullable
         byte[] val,
         GridSwapContext ctx)
           throws GridSpiException

Stores value as array of bytes with given key into data space with given name.

Specified by:

store in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to store key-value pair into.

key - Key to store given value for. This key can be used further to read or remove stored value.

val - Some value as array of bytes to store into specified data space.

ctx - Swap context.

Throws:

GridSpiException - In case of any errors.

storeAll

public void storeAll(@Nullable
            String spaceName,
            Map<GridSwapKey,byte[]> pairs,
            GridSwapContext ctx)
              throws GridSpiException

Stores key-value pairs (both keys and values are arrays of bytes) into data space with given name.

Specified by:

storeAll in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name to store key-value pairs into.

pairs - Map of stored key-value pairs where each one is an array of bytes.

ctx - Swap context.

Throws:

GridSpiException - In case of any errors.

setListener

public void setListener(@Nullable
               GridSwapSpaceSpiListener evictLsnr)

Sets eviction listener to receive notifications on evicted swap entries.

Specified by:

setListener in interface GridSwapSpaceSpi

Parameters:

evictLsnr - Eviction listener (null to stop receiving notifications).

partitions

@Nullable
public Collection<Integer> partitions(@Nullable
                                      String spaceName)
                               throws GridSpiException

Gets partitions IDs that are stored in the passed in space.

Specified by:

partitions in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name.

Returns:

Partitions IDs or null if space is unknown.

Throws:

GridSpiException - If failed.

keyIterator

@Nullable
public <K> GridSpiCloseableIterator<K> keyIterator(@Nullable
                                                   String spaceName,
                                                   GridSwapContext ctx)
                                        throws GridSpiException

Gets iterator over space keys.

Specified by:

keyIterator in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name.

ctx - Swap context.

Returns:

Iterator over space entries or null if space is unknown.

Throws:

GridSpiException - If failed.

rawIterator

@Nullable
public GridSpiCloseableIterator<Map.Entry<byte[],byte[]>> rawIterator(@Nullable
                                                                      String spaceName)
                                                               throws GridSpiException

Gets raw iterator over space entries.

Specified by:

rawIterator in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name.

Returns:

Iterator over space entries or null if space is unknown.

Throws:

GridSpiException - If failed.

rawIterator

@Nullable
public GridSpiCloseableIterator<Map.Entry<byte[],byte[]>> rawIterator(@Nullable
                                                                      String spaceName,
                                                                      int part)
                                                               throws GridSpiException

Gets raw iterator over space entries.

Specified by:

rawIterator in interface GridSwapSpaceSpi

Parameters:

spaceName - Space name.

part - Partition.

Returns:

Iterator over space entries or null if space is unknown.

Throws:

GridSpiException - If failed.

toString

public String toString()

Overrides:

toString in class Object