GridJdbcCheckpointSpi (gridgain-core 6.1.9 API)

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

All Implemented Interfaces:

GridCheckpointSpi, GridJdbcCheckpointSpiMBean, GridSpi, GridSpiManagementMBean
```
@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 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
GridJdbcCheckpointSpi can be configured as follows:
```
 GridConfiguration cfg = new GridConfiguration();

 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.GridConfiguration" 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

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`).

Constructor Summary

Constructors
Constructor and Description

GridJdbcCheckpointSpi()

Constructors
Constructor and Description
`GridJdbcCheckpointSpi()`

Method Summary

Methods
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(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`	`setPwd(String pwd)` 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, checkConfigurationConsistency0, configInfo, createSpiAttributeName, getConsistentAttributeNames, getGridGainHome, getLocalNodeId, getName, getNodeAttributes, getSpiContext, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted, injectables, onContextDestroyed, onContextInitialized, onContextInitialized0, registerMBean, 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, onContextDestroyed, onContextInitialized

Methods inherited from interface org.gridgain.grid.spi.GridSpiManagementMBean
getGridGainHome, getLocalNodeId, getName, getStartTimestamp, getStartTimestampFormatted, getUpTime, getUpTimeFormatted

- 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.
  - getPwd
```
public String getPwd()
```
    Gets checkpoint jdbc password.
    
    Specified by:
    
    getPwd 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 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:
    setPwd(String)
  - setPwd
```
@GridSpiConfiguration(optional=true)
public void 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.
    See Also:
    setUser(String)
  - setCheckpointTableName
```
@GridSpiConfiguration(optional=true)
public void setCheckpointTableName(String tblName)
```
    Sets checkpoint table name. By default 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, 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.
  - 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 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 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.
  - 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 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 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.
  - setExpireDateFieldType
```
@GridSpiConfiguration(optional=true)
public void 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.
  - 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
    
    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.
  - onContextDestroyed0
```
protected void onContextDestroyed0()
```
    Method to be called in the beginning of onContextDestroyed() method.
    
    Overrides:
    
    onContextDestroyed0 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
    
    Parameters:
    key - Checkpoint key.
    
    Returns:
    Loaded data or null if there is no data for a given key.
    
    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.
  - 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
    
    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:
    
    GridSpiException - Thrown in case of any error while saving checkpoint data.
  - setCheckpointListener
```
public void setCheckpointListener(GridCheckpointListener lsnr)
```
    Sets the checkpoint listener.
    
    Specified by:
    
    setCheckpointListener in interface GridCheckpointSpi
    
    Parameters:
    lsnr - The listener to set or null.

Class GridJdbcCheckpointSpi

Configuration

Mandatory

Optional

Apache DBCP

Java Example

Spring Example

Field Summary

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

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

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

Field Detail

DFLT_NUMBER_OF_RETRIES

DFLT_EXPIRE_DATE_FIELD_TYPE

DFLT_EXPIRE_DATE_FIELD_NAME

DFLT_VALUE_FIELD_TYPE

DFLT_VALUE_FIELD_NAME

DFLT_KEY_FIELD_TYPE

DFLT_KEY_FIELD_NAME

DFLT_CHECKPOINT_TABLE_NAME

Constructor Detail

GridJdbcCheckpointSpi

Method Detail

getNumberOfRetries

getDataSourceInfo

getUser

getPwd

getCheckpointTableName

getKeyFieldName

getKeyFieldType

getValueFieldName

getValueFieldType

getExpireDateFieldName

getExpireDateFieldType

setDataSource

setNumberOfRetries

setUser

setPwd

setCheckpointTableName

setKeyFieldName

setKeyFieldType

setValueFieldName

setValueFieldType

setExpireDateFieldName

setExpireDateFieldType

spiStart

spiStop

onContextDestroyed0

loadCheckpoint

removeCheckpoint

saveCheckpoint

setCheckpointListener