org.gridgain.grid.spi.checkpoint.jdbc
Class GridJdbcCheckpointSpi

java.lang.Object
  org.gridgain.grid.spi.GridSpiAdapter
      org.gridgain.grid.spi.checkpoint.jdbc.GridJdbcCheckpointSpi

All Implemented Interfaces:

GridCheckpointSpi, GridJdbcCheckpointSpiMBean, GridSpi, GridSpiJsonConfigurable, GridSpiManagementMBean

@GridSpiInfo(author="GridGain Systems",
             url="www.gridgain.com",
             email="support@gridgain.com",
             version="3.6.0e.13012012")
@GridSpiMultipleInstancesSupport(value=true)
public class GridJdbcCheckpointSpi
extends GridSpiAdapter
implements GridCheckpointSpi, GridJdbcCheckpointSpiMBean

This class defines JDBC checkpoint SPI implementation. All checkpoints are stored in the database table and available from all nodes in the grid. Note that every node must have access to the database. The reason of having it is because a job state can be saved on one node and loaded on another (e.g., if a job gets preempted on a different node after node failure).

Configuration

Mandatory

This SPI has following mandatory configuration parameters.

• DataSource (see GridJdbcCheckpointSpi.setDataSource(DataSource)).

Optional

This SPI has following optional configuration parameters:

• Checkpoint table name (see GridJdbcCheckpointSpi.setCheckpointTableName(String)).
• Checkpoint key field name (see GridJdbcCheckpointSpi.setKeyFieldName(String)).
• Checkpoint key field type (see GridJdbcCheckpointSpi.setKeyFieldType(String)).
• Checkpoint value field name (see GridJdbcCheckpointSpi.setValueFieldName(String)).
• Checkpoint value field type (see GridJdbcCheckpointSpi.setValueFieldType(String)).
• Checkpoint expiration date field name (see GridJdbcCheckpointSpi.setExpireDateFieldName(String)).
• Checkpoint expiration date field type (see GridJdbcCheckpointSpi.setExpireDateFieldType(String)).
• Number of retries in case of any failure (see GridJdbcCheckpointSpi.setNumberOfRetries(int)).
• User name (see GridJdbcCheckpointSpi.setUser(String)).
• Password (see GridJdbcCheckpointSpi.setPassword(String)).

Apache DBCP

Apache DBCP project provides various wrappers for data sources and connection pools. You can use these wrappers as Spring beans to configure this SPI from Spring configuration file. Refer to Apache DBCP project for more information.

Java Example

GridJdbcCheckpointSpi can be configured as follows:

 GridConfigurationAdapter cfg = new GridConfigurationAdapter();

 GridJdbcCheckpointSpi checkpointSpi = new GridJdbcCheckpointSpi();

 javax.sql.DataSource ds = ... // Set datasource.

 // Set jdbc checkpoint SPI parameters.
 checkpointSpi.setDataSource(ds);
 checkpointSpi.setUser("test");
 checkpointSpi.setPassword("test");

 // Override default checkpoint SPI.
 cfg.setCheckpointSpi(checkpointSpi);

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

Spring Example

GridJdbcCheckpointSpi can be configured from Spring XML configuration file:

 <bean id="grid.custom.cfg" class="org.gridgain.grid.GridConfigurationAdapter" singleton="true">
     ...
     <property name="checkpointSpi">
         <bean class="org.gridgain.grid.spi.checkpoint.jdbc.GridJdbcCheckpointSpi">
             <property name="dataSrc"><ref bean="anyPooledDataSourceBean" /></property>
             <property name="checkpointTableName" value="GRID_CHECKPOINTS" />
             <property name="user" value="test" />
             <property name="password" value="test" />
         </bean>
     </property>
     ...
 </bean>
 

For information about Spring framework visit www.springframework.org

Wiki & Forum:

Wiki
Forum

Field Summary

static String	DFLT_CHECKPOINT_TABLE_NAME Default checkpoint table name (value is CHECKPOINTS).
static String	DFLT_EXPIRE_DATE_FIELD_NAME Default expiration date field name (value is EXPIRE_DATE).
static String	DFLT_EXPIRE_DATE_FIELD_TYPE Default expiration date field type (value is DATETIME).
static String	DFLT_KEY_FIELD_NAME Default checkpoint key field name (value is NAME).
static String	DFLT_KEY_FIELD_TYPE Default checkpoint key field type (value is VARCHAR(256)).
static int	DFLT_NUMBER_OF_RETRIES Default number of retries in case of errors (value is 2).
static String	DFLT_VALUE_FIELD_NAME Default checkpoint value field name (value is VALUE).
static String	DFLT_VALUE_FIELD_TYPE Default checkpoint value field type (value is BLOB).

Constructor Summary

GridJdbcCheckpointSpi()

Method Summary

String	getCheckpointTableName() Gets checkpoint table name.
String	getDataSourceInfo() Gets data source description.
String	getExpireDateFieldName() Gets expiration date field name for checkpoint table.
String	getExpireDateFieldType() Gets expiration date field type for checkpoint table.
String	getKeyFieldName() Gets key field name for checkpoint table.
String	getKeyFieldType() Gets key field type for checkpoint table.
int	getNumberOfRetries() Gets number of retries in case of DB failure.
String	getPassword() Gets checkpoint jdbc password.
String	getUser() Gets checkpoint jdbc user name.
String	getValueFieldName() Gets value field name for checkpoint table.
String	getValueFieldType() Gets value field type for checkpoint table.
byte[]	loadCheckpoint(String key) Loads checkpoint from storage by its unique key.
void	onContextDestroyed() Callback invoked prior to stopping grid before SPI context is destroyed.
boolean	removeCheckpoint(String key) This method instructs the checkpoint provider to clean saved data for a given key.
boolean	saveCheckpoint(String key, byte[] state, long timeout, boolean overwrite) Saves checkpoint to the storage.
void	setCheckpointListener(GridCheckpointListener lsnr) Sets the checkpoint listener.
void	setCheckpointTableName(String tblName) Sets checkpoint table name.
void	setDataSource(DataSource dataSrc) Sets DataSource to use for database access.
void	setExpireDateFieldName(String expDateName) Sets checkpoint expiration date field name.
void	setExpireDateFieldType(String expDateType) Sets checkpoint expiration date field type.
void	setKeyFieldName(String keyName) Sets checkpoint key field name.
void	setKeyFieldType(String keyType) Sets checkpoint key field type.
void	setNumberOfRetries(int retryNum) Sets number of retries in case of any database errors.
void	setPassword(String password) Sets checkpoint database password.
void	setUser(String user) Sets checkpoint database user name.
void	setValueFieldName(String valName) Sets checkpoint value field name.
void	setValueFieldType(String valType) Sets checkpoint value field type.
void	spiStart(String gridName) This method is called to start SPI.
void	spiStop() This method is called to stop SPI.

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

assertParameter, checkConfigurationConsistency, configInfo, createSpiAttributeName, getAuthor, getConsistentAttributeNames, getGridGainHome, getLocalNodeId, getName, getNodeAttributes, getSpiContext, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted, getVendorEmail, getVendorUrl, getVersion, injectables, onContextInitialized, registerMBean, setJson, setName, startInfo, startStopwatch, stopInfo, unregisterMBean

Methods inherited from class java.lang.Object

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

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

getName, getNodeAttributes, onContextInitialized

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

getAuthor, getGridGainHome, getLocalNodeId, getName, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted, getVendorEmail, getVendorUrl, getVersion

Field Detail

DFLT_NUMBER_OF_RETRIES

public static final int DFLT_NUMBER_OF_RETRIES

Default number of retries in case of errors (value is 2).

See Also:

Constant Field Values

DFLT_EXPIRE_DATE_FIELD_TYPE

public static final String DFLT_EXPIRE_DATE_FIELD_TYPE

Default expiration date field type (value is DATETIME).

See Also:

Constant Field Values

DFLT_EXPIRE_DATE_FIELD_NAME

public static final String DFLT_EXPIRE_DATE_FIELD_NAME

Default expiration date field name (value is EXPIRE_DATE).

See Also:

Constant Field Values

DFLT_VALUE_FIELD_TYPE

public static final String DFLT_VALUE_FIELD_TYPE

Default checkpoint value field type (value is BLOB).

See Also:

Constant Field Values

DFLT_VALUE_FIELD_NAME

public static final String DFLT_VALUE_FIELD_NAME

Default checkpoint value field name (value is VALUE).

See Also:

Constant Field Values

DFLT_KEY_FIELD_TYPE

public static final String DFLT_KEY_FIELD_TYPE

Default checkpoint key field type (value is VARCHAR(256)).

See Also:

Constant Field Values

DFLT_KEY_FIELD_NAME

public static final String DFLT_KEY_FIELD_NAME

Default checkpoint key field name (value is NAME).

See Also:

Constant Field Values

DFLT_CHECKPOINT_TABLE_NAME

public static final String DFLT_CHECKPOINT_TABLE_NAME

Default checkpoint table name (value is CHECKPOINTS).

See Also:

Constant Field Values

Constructor Detail

GridJdbcCheckpointSpi

public GridJdbcCheckpointSpi()

Method Detail

getNumberOfRetries

public int getNumberOfRetries()

Gets number of retries in case of DB failure.

Specified by:

getNumberOfRetries in interface GridJdbcCheckpointSpiMBean

Returns:

Number of retries.

getDataSourceInfo

public String getDataSourceInfo()

Gets data source description.

Specified by:

getDataSourceInfo in interface GridJdbcCheckpointSpiMBean

Returns:

Description for data source.

getUser

public String getUser()

Gets checkpoint jdbc user name.

Specified by:

getUser in interface GridJdbcCheckpointSpiMBean

Returns:

User name for checkpoint jdbc.

getPassword

public String getPassword()

Gets checkpoint jdbc password.

Specified by:

getPassword in interface GridJdbcCheckpointSpiMBean

Returns:

Password for checkpoint jdbc.

getCheckpointTableName

public String getCheckpointTableName()

Gets checkpoint table name.

Specified by:

getCheckpointTableName in interface GridJdbcCheckpointSpiMBean

Returns:

Checkpoint table name.

getKeyFieldName

public String getKeyFieldName()

Gets key field name for checkpoint table.

Specified by:

getKeyFieldName in interface GridJdbcCheckpointSpiMBean

Returns:

Key field name for checkpoint table.

getKeyFieldType

public String getKeyFieldType()

Gets key field type for checkpoint table.

Specified by:

getKeyFieldType in interface GridJdbcCheckpointSpiMBean

Returns:

Key field type for checkpoint table.

getValueFieldName

public String getValueFieldName()

Gets value field name for checkpoint table.

Specified by:

getValueFieldName in interface GridJdbcCheckpointSpiMBean

Returns:

Value field name for checkpoint table.

getValueFieldType

public String getValueFieldType()

Gets value field type for checkpoint table.

Specified by:

getValueFieldType in interface GridJdbcCheckpointSpiMBean

Returns:

Value field type for checkpoint table.

getExpireDateFieldName

public String getExpireDateFieldName()

Gets expiration date field name for checkpoint table.

Specified by:

getExpireDateFieldName in interface GridJdbcCheckpointSpiMBean

Returns:

Create date field name for checkpoint table.

getExpireDateFieldType

public String getExpireDateFieldType()

Gets expiration date field type for checkpoint table.

Specified by:

getExpireDateFieldType in interface GridJdbcCheckpointSpiMBean

Returns:

Expiration date field type for checkpoint table.

setDataSource

@GridSpiConfiguration(optional=false)
public void setDataSource(DataSource dataSrc)

Sets DataSource to use for database access. This parameter is mandatory and must be provided for this SPI to be able to start.

Apache DBCP project provides various wrappers for data sources and connection pools. You can use these wrappers as Spring beans to configure this SPI from Spring configuration file. Refer to Apache DBCP project for more information.

Parameters:

dataSrc - DataSource object to set.

setNumberOfRetries

@GridSpiConfiguration(optional=true)
public void setNumberOfRetries(int retryNum)

Sets number of retries in case of any database errors. By default the value is GridJdbcCheckpointSpi.DFLT_NUMBER_OF_RETRIES.

Parameters:

retryNum - Number of retries in case of any database errors.

setUser

@GridSpiConfiguration(optional=true)
public void setUser(String user)

Sets checkpoint database user name. Note that authentication will be performed only if both, user and password are set.

Parameters:

user - Checkpoint database user name to set.

See Also:

GridJdbcCheckpointSpi.setPassword(String)

setPassword

@GridSpiConfiguration(optional=true)
public void setPassword(String password)

Sets checkpoint database password. Note that authentication will be performed only if both, user and password are set.

Parameters:

password - Checkpoint database password to set.

See Also:

GridJdbcCheckpointSpi.setUser(String)

setCheckpointTableName

@GridSpiConfiguration(optional=true)
public void setCheckpointTableName(String tblName)

Sets checkpoint table name. By default GridJdbcCheckpointSpi.DFLT_CHECKPOINT_TABLE_NAME is used.

Parameters:

tblName - Checkpoint table name to set.

setKeyFieldName

@GridSpiConfiguration(optional=true)
public void setKeyFieldName(String keyName)

Sets checkpoint key field name. By default, GridJdbcCheckpointSpi.DFLT_KEY_FIELD_NAME is used. Note that you may also want to change key field type (see GridJdbcCheckpointSpi.setKeyFieldType(String)).

Parameters:

keyName - Checkpoint key field name to set.

setKeyFieldType

@GridSpiConfiguration(optional=true)
public void setKeyFieldType(String keyType)

Sets checkpoint key field type. The field should have corresponding SQL string type (VARCHAR, for example). By default GridJdbcCheckpointSpi.DFLT_EXPIRE_DATE_FIELD_TYPE is used.

Parameters:

keyType - Checkpoint key field type to set.

setValueFieldName

@GridSpiConfiguration(optional=true)
public void setValueFieldName(String valName)

Sets checkpoint value field name. By default GridJdbcCheckpointSpi.DFLT_VALUE_FIELD_NAME is used. Note that you may also want to change the value type (see GridJdbcCheckpointSpi.setValueFieldType(String)).

Parameters:

valName - Checkpoint value field name to set.

setValueFieldType

@GridSpiConfiguration(optional=true)
public void setValueFieldType(String valType)

Sets checkpoint value field type. Note, that the field should have corresponding SQL BLOB type, and the default value of GridJdbcCheckpointSpi.DFLT_VALUE_FIELD_TYPE, which is BLOB, won't work for all databases. For example, if using HSQL DB, then the type should be longvarbinary.

Parameters:

valType - Checkpoint value field type to set.

setExpireDateFieldName

@GridSpiConfiguration(optional=true)
public void setExpireDateFieldName(String expDateName)

Sets checkpoint expiration date field name. By default GridJdbcCheckpointSpi.DFLT_EXPIRE_DATE_FIELD_NAME is used. Note that you may also want to change the expiration date field type (see GridJdbcCheckpointSpi.setExpireDateFieldType(String)).

Parameters:

expDateName - Checkpoint expiration date field name to set.

setExpireDateFieldType

@GridSpiConfiguration(optional=true)
public void setExpireDateFieldType(String expDateType)

Sets checkpoint expiration date field type. By default GridJdbcCheckpointSpi.DFLT_EXPIRE_DATE_FIELD_TYPE is used. The field should have corresponding SQL DATETIME type.

Parameters:

expDateType - Checkpoint expiration date field type to set.

spiStart

public void spiStart(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

Throws:

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

Parameters:

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

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.

onContextDestroyed

public void onContextDestroyed()

Callback invoked prior to stopping grid before SPI context is destroyed. Once this method is complete, grid will begin shutdown sequence. Use this callback for de-initialization logic that may involve SPI context. Note that invoking SPI context after this callback is complete is considered illegal and may produce unknown results.

If GridSpiAdapter is used for SPI implementation, then it will replace actual context with dummy no-op context which is usually good-enough since grid is about to shut down.

Specified by:

onContextDestroyed in interface GridSpi

Overrides:

onContextDestroyed in class GridSpiAdapter

loadCheckpoint

public byte[] loadCheckpoint(String key)
                      throws GridSpiException

Loads checkpoint from storage by its unique key.

Specified by:

loadCheckpoint in interface GridCheckpointSpi

Throws:

GridSpiException - Thrown in case of any error while loading checkpoint data. Note that in case when given key is not found this method will return null.

Parameters:

key - Checkpoint key.

Returns:

Loaded data or null if there is no data for a given key.

removeCheckpoint

public boolean removeCheckpoint(String key)

This method instructs the checkpoint provider to clean saved data for a given key.

Specified by:

removeCheckpoint in interface GridCheckpointSpi

Parameters:

key - Key for the checkpoint to remove.

Returns:

true if data has been actually removed, false otherwise.

saveCheckpoint

public boolean saveCheckpoint(String key,
                              byte[] state,
                              long timeout,
                              boolean overwrite)
                       throws GridSpiException

Saves checkpoint to the storage.

Specified by:

saveCheckpoint in interface GridCheckpointSpi

Throws:

GridSpiException - Thrown in case of any error while saving checkpoint data.

Parameters:

key - Checkpoint unique key.

state - Saved data.

timeout - Every intermediate data stored by checkpoint provider should have a timeout. Timeout allows for effective resource management by checkpoint provider by cleaning saved data that are not needed anymore. Generally, the user should choose the minimum possible timeout to avoid long-term resource acquisition by checkpoint provider. Value 0 means that timeout will never expire.

overwrite - Whether or not overwrite checkpoint if it already exists.

Returns:

true if checkpoint has been actually saved, false otherwise.

setCheckpointListener

public void setCheckpointListener(GridCheckpointListener lsnr)

Sets the checkpoint listener.

Specified by:

setCheckpointListener in interface GridCheckpointSpi

Parameters:

lsnr - The listener to set or null.