Package org.apache.ignite.spi.failover.always

Class AlwaysFailoverSpi

  • All Implemented Interfaces:
    FailoverSpi, IgniteSpi
    @IgniteSpiMultipleInstancesSupport(true)
@IgniteSpiConsistencyChecked(optional=true)
public class AlwaysFailoverSpi
extends IgniteSpiAdapter
implements FailoverSpi
    Failover SPI that always reroutes a failed job to another node. Note, that at first an attempt will be made to reroute the failed job to a node that was not part of initial split for a better chance of success. If no such nodes are available, then an attempt will be made to reroute the failed job to the nodes in the initial split minus the node the job is failed on. If none of the above attempts succeeded, then the job will not be failed over and null will be returned.

    Configuration

    This SPI is default failover SPI and does not have to be explicitly configured unless configuration parameters need to be changed.

    Mandatory

    This SPI has no mandatory configuration parameters.

    Optional

    This SPI has following optional configuration parameters:
    • Maximum failover attempts for a single job (see setMaximumFailoverAttempts(int)). If maximum failover attempts is reached, then job will not be failed-over and, hence, will fail.
    Here is a Java example how to configure grid with AlwaysFailoverSpi failover SPI. 
     AlwaysFailoverSpi spi = new AlwaysFailoverSpi();

 // Override maximum failover attempts.
 spi.setMaximumFailoverAttempts(5);

 IgniteConfiguration cfg = new IgniteConfiguration();

 // Override default failover SPI.
 cfg.setFailoverSpiSpi(spi);

 // Starts grid.
 G.start(cfg);
    Here is an example of how to configure AlwaysFailoverSpi from Spring XML configuration file. 
     <property name="failoverSpi">
     <bean class="org.apache.ignite.spi.failover.always.AlwaysFailoverSpi">
         <property name="maximumFailoverAttempts" value="5"/>
     </bean>
 </property>


    For information about Spring framework visit www.springframework.org

    See Also:
    FailoverSpi

    • Field Detail

      • DFLT_MAX_FAILOVER_ATTEMPTS

        public static final int DFLT_MAX_FAILOVER_ATTEMPTS
        Maximum number of attempts to execute a failed job on another node (default is 5).
        See Also:
        Constant Field Values

      • AFFINITY_CALL_ATTEMPT

        public static final String AFFINITY_CALL_ATTEMPT
        Name of job context attribute containing number of affinity call attempts.
        See Also:
        Constant Field Values

      • MAX_FAILOVER_ATTEMPT_ATTR

        public static final String MAX_FAILOVER_ATTEMPT_ATTR
        Maximum attempts attribute key should be the same on all nodes.
        See Also:
        Constant Field Values

    • Constructor Detail

      • AlwaysFailoverSpi

        public AlwaysFailoverSpi()

    • Method Detail

      • getMaximumFailoverAttempts

        public int getMaximumFailoverAttempts()
        See setMaximumFailoverAttempts(int).
        Returns:
        Maximum number of attempts to execute a failed job on another node.

      • setMaximumFailoverAttempts

        @IgniteSpiConfiguration(optional=true)
public AlwaysFailoverSpi setMaximumFailoverAttempts​(int maxFailoverAttempts)
        Sets maximum number of attempts to execute a failed job on another node. If not specified, DFLT_MAX_FAILOVER_ATTEMPTS value will be used.
        Parameters:
        maxFailoverAttempts - Maximum number of attempts to execute a failed job on another node.
        Returns:
        this for chaining.

      • getTotalFailoverJobsCount

        public int getTotalFailoverJobsCount()
        Get total number of jobs that were failed over.
        Returns:
        Total number of failed over jobs.

      • 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.

      • getConsistentAttributeNames

        protected List<String> getConsistentAttributeNames()
        Returns back a list of attributes that should be consistent for this SPI. Consistency means that remote node has to have the same attribute with the same value.
        Overrides:
        getConsistentAttributeNames in class IgniteSpiAdapter
        Returns:
        List or attribute names.