org.apache.ignite.spi.checkpoint.jdbc

Class JdbcCheckpointSpi

java.lang.Object

org.apache.ignite.spi.IgniteSpiAdapter

org.apache.ignite.spi.checkpoint.jdbc.JdbcCheckpointSpi

All Implemented Interfaces:

CheckpointSpi, IgniteSpi

@IgniteSpiMultipleInstancesSupport(value=true)
public class JdbcCheckpointSpi
extends IgniteSpiAdapter
implements CheckpointSpi

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 setDataSource(DataSource)).

Optional

This SPI has following optional configuration parameters:

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

JdbcCheckpointSpi can be configured as follows:

 IgniteConfiguration cfg = new IgniteConfiguration();

 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

JdbcCheckpointSpi can be configured from Spring XML configuration file:

 <bean id="grid.custom.cfg" class="org.apache.ignite.configuration.IgniteConfiguration" singleton="true">
     ...
     <property name="checkpointSpi">
         <bean class="org.apache.ignite.spi.checkpoint.jdbc.JdbcCheckpointSpi">
             <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

Field Summary

Fields

Modifier and Type	Field and Description
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).

Fields inherited from class org.apache.ignite.spi.IgniteSpiAdapter

ignite, igniteInstanceName

Constructor Summary

Constructors

Constructor and Description
JdbcCheckpointSpi()

Method Summary

Modifier and Type	Method and Description
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	getPwd() 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.
protected void	onContextDestroyed0() Method to be called in the beginning of onContextDestroyed() method.
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(CheckpointListener lsnr) Sets the checkpoint listener.
JdbcCheckpointSpi	setCheckpointTableName(String tblName) Sets checkpoint table name.
JdbcCheckpointSpi	setDataSource(DataSource dataSrc) Sets DataSource to use for database access.
JdbcCheckpointSpi	setExpireDateFieldName(String expDateName) Sets checkpoint expiration date field name.
JdbcCheckpointSpi	setExpireDateFieldType(String expDateType) Sets checkpoint expiration date field type.
JdbcCheckpointSpi	setKeyFieldName(String keyName) Sets checkpoint key field name.
JdbcCheckpointSpi	setKeyFieldType(String keyType) Sets checkpoint key field type.
JdbcCheckpointSpi	setName(String name) Sets SPI name.
JdbcCheckpointSpi	setNumberOfRetries(int retryNum) Sets number of retries in case of any database errors.
JdbcCheckpointSpi	setPwd(String pwd) Sets checkpoint database password.
JdbcCheckpointSpi	setUser(String user) Sets checkpoint database user name.
JdbcCheckpointSpi	setValueFieldName(String valName) Sets checkpoint value field name.
JdbcCheckpointSpi	setValueFieldType(String valType) Sets checkpoint value field type.
void	spiStart(String igniteInstanceName) This method is called to start SPI.
void	spiStop() This method is called to stop SPI.

Methods inherited from class org.apache.ignite.spi.IgniteSpiAdapter

addTimeoutObject, assertParameter, checkConfigurationConsistency0, clientFailureDetectionTimeout, configInfo, createSpiAttributeName, failureDetectionTimeout, failureDetectionTimeoutEnabled, failureDetectionTimeoutEnabled, getConsistentAttributeNames, getExceptionRegistry, getLocalNode, getName, getNodeAttributes, getSpiContext, ignite, initFailureDetectionTimeout, injectables, injectResources, isNodeStopping, onBeforeStart, onClientDisconnected, onClientReconnected, onContextDestroyed, onContextInitialized, onContextInitialized0, registerMBean, removeTimeoutObject, started, 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.apache.ignite.spi.IgniteSpi

getName, getNodeAttributes, onClientDisconnected, onClientReconnected, onContextDestroyed, onContextInitialized

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

JdbcCheckpointSpi

public JdbcCheckpointSpi()

Method Detail

getNumberOfRetries

public int getNumberOfRetries()

Gets number of retries in case of DB failure.

Returns:

Number of retries.

getDataSourceInfo

public String getDataSourceInfo()

Gets data source description.

Returns:

Description for data source.

getUser

public String getUser()

Gets checkpoint jdbc user name.

Returns:

User name for checkpoint jdbc.

getPwd

public String getPwd()

Gets checkpoint jdbc password.

Returns:

Password for checkpoint jdbc.

getCheckpointTableName

public String getCheckpointTableName()

Gets checkpoint table name.

Returns:

Checkpoint table name.

getKeyFieldName

public String getKeyFieldName()

Gets key field name for checkpoint table.

Returns:

Key field name for checkpoint table.

getKeyFieldType

public String getKeyFieldType()

Gets key field type for checkpoint table.

Returns:

Key field type for checkpoint table.

getValueFieldName

public String getValueFieldName()

Gets value field name for checkpoint table.

Returns:

Value field name for checkpoint table.

getValueFieldType

public String getValueFieldType()

Gets value field type for checkpoint table.

Returns:

Value field type for checkpoint table.

getExpireDateFieldName

public String getExpireDateFieldName()

Gets expiration date field name for checkpoint table.

Returns:

Create date field name for checkpoint table.

getExpireDateFieldType

public String getExpireDateFieldType()

Gets expiration date field type for checkpoint table.

Returns:

Expiration date field type for checkpoint table.

setDataSource

@IgniteSpiConfiguration(optional=false)
public JdbcCheckpointSpi 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.

Returns:

this for chaining.

setNumberOfRetries

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setNumberOfRetries(int retryNum)

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

Parameters:

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

Returns:

this for chaining.

setUser

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi 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. null is a valid value that means that no user provided. Authentication won't be performed in this case.

Returns:

this for chaining.

See Also:

setPwd(String)

setPwd

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setPwd(String pwd)

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

Parameters:

pwd - Checkpoint database password to set. null is a valid value that means that no password provided. Authentication won't be performed in this case.

Returns:

this for chaining.

See Also:

setUser(String)

setCheckpointTableName

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setCheckpointTableName(String tblName)

Sets checkpoint table name. By default DFLT_CHECKPOINT_TABLE_NAME is used.

Parameters:

tblName - Checkpoint table name to set.

Returns:

this for chaining.

setKeyFieldName

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setKeyFieldName(String keyName)

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

Parameters:

keyName - Checkpoint key field name to set.

Returns:

this for chaining.

setKeyFieldType

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setKeyFieldType(String keyType)

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

Parameters:

keyType - Checkpoint key field type to set.

Returns:

this for chaining.

setValueFieldName

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setValueFieldName(String valName)

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

Parameters:

valName - Checkpoint value field name to set.

Returns:

this for chaining.

setValueFieldType

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setValueFieldType(String valType)

Sets checkpoint value field type. Note, that the field should have corresponding SQL BLOB type, and the default value of 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.

Returns:

this for chaining.

setExpireDateFieldName

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setExpireDateFieldName(String expDateName)

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

Parameters:

expDateName - Checkpoint expiration date field name to set.

Returns:

this for chaining.

setExpireDateFieldType

@IgniteSpiConfiguration(optional=true)
public JdbcCheckpointSpi setExpireDateFieldType(String expDateType)

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

Parameters:

expDateType - Checkpoint expiration date field type to set.

Returns:

this for chaining.

spiStart

public void spiStart(String igniteInstanceName)
              throws IgniteSpiException

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

Specified by:

spiStart in interface IgniteSpi

Parameters:

igniteInstanceName - Name of Ignite instance this SPI is being started for (null for default Ignite instance).

Throws:

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

spiStop

public void spiStop()
             throws IgniteSpiException

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 IgniteSpi

Throws:

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

onContextDestroyed0

protected void onContextDestroyed0()

Method to be called in the beginning of onContextDestroyed() method.

Overrides:

onContextDestroyed0 in class IgniteSpiAdapter

loadCheckpoint

public byte[] loadCheckpoint(String key)
                      throws IgniteSpiException

Loads checkpoint from storage by its unique key.

Specified by:

loadCheckpoint in interface CheckpointSpi

Parameters:

key - Checkpoint key.

Returns:

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

Throws:

IgniteSpiException - 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.

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 CheckpointSpi

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 IgniteSpiException

Saves checkpoint to the storage.

Specified by:

saveCheckpoint in interface CheckpointSpi

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.

Throws:

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

setCheckpointListener

public void setCheckpointListener(CheckpointListener lsnr)

Sets the checkpoint listener.

Specified by:

setCheckpointListener in interface CheckpointSpi

Parameters:

lsnr - The listener to set or null.

setName

public JdbcCheckpointSpi setName(String name)

Sets SPI name.

Overrides:

setName in class IgniteSpiAdapter

Parameters:

name - SPI name.

Returns:

this for chaining.