com.ibm.streamsx.topology.consistent

Class ConsistentRegionConfig

java.lang.Object

com.ibm.streamsx.topology.consistent.ConsistentRegionConfig

public final class ConsistentRegionConfig
extends java.lang.Object

Immutable consistent region configuration. The default values for a ConsistentRegionConfig are:

• drainTimeout - 180 seconds - Indicates the maximum time in seconds that the drain and checkpoint of the region is allotted to finish processing. If the process takes longer than the specified time, a failure is reported and the region is reset to the point of the previously successfully established consistent state.
• resetTimeout - 180 seconds - Indicates the maximum time in seconds that the reset of the region is allotted to finish processing. If the process takes longer than the specified time, a failure is reported and another reset of the region is attempted
• maxConsecutiveResetAttempts - 5 - Indicates the maximum number of consecutive attempts to reset a consistent region. After a failure, if the maximum number of attempts is reached, the region stops processing new tuples. After the maximum number of consecutive attempts is reached, a region can be reset only with manual intervention or with a program with a call to a method in the consistent region controller.

A configuration has time unit that applies to getPeriod(), getDrainTimeout() and getResetTimeout(). The time unit is hard-coded to TimeUnit.SECONDS, future versions may allow creating configurations with a different time unit.

Example Use:

 
 // set source to be a the start of an operator driven consistent region
 // with a drain timeout of five seconds and a reset timeout of twenty seconds.
 source.setConsistent(operatorDriven().drainTimeout(5).resetTimeout(20));
 
 

See Also:

TStream.setConsistent(ConsistentRegionConfig)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ConsistentRegionConfig.Trigger Defines how the drain-checkpoint cycle of a consistent region is triggered.

Constructor Summary

Constructors

Constructor and Description
ConsistentRegionConfig() Create a ConsistentRegionConfig.Trigger.OPERATOR_DRIVEN consistent region configuration.
ConsistentRegionConfig(int period) Create a ConsistentRegionConfig.Trigger.PERIODIC consistent region configuration.

Method Summary

Modifier and Type	Method and Description
ConsistentRegionConfig	drainTimeout(long drainTimeout) Return a new configuration changing drainTimeout.
boolean	equals(java.lang.Object obj)
long	getDrainTimeout() Get the drain timeout for this configuration.
int	getMaxConsecutiveResetAttempts() Get the maximum number of consecutive reset attempts.
long	getPeriod() Get the trigger period.
long	getResetTimeout() Get the reset timeout for this configuration.
java.util.concurrent.TimeUnit	getTimeUnit() Get the time unit for getPeriod(), getDrainTimeout() and getResetTimeout()().
ConsistentRegionConfig.Trigger	getTrigger() Get the trigger type.
int	hashCode()
ConsistentRegionConfig	maxConsecutiveResetAttempts(int attempts) Return a new configuration changing maxConsecutiveResetAttempts.
static ConsistentRegionConfig	operatorDriven() Create a ConsistentRegionConfig.Trigger.OPERATOR_DRIVEN consistent region configuration.
static ConsistentRegionConfig	periodic(int period) Create a ConsistentRegionConfig.Trigger.PERIODIC consistent region configuration.
ConsistentRegionConfig	resetTimeout(long resetTimeout) Return a new configuration changing resetTimeout.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConsistentRegionConfig

public ConsistentRegionConfig()

Create a ConsistentRegionConfig.Trigger.OPERATOR_DRIVEN consistent region configuration. The source operator drives when a region is drained and checkpointed, for example a messaging source might drain and checkpoint every ten thousand messages.
Configuration values are set to the default values.

ConsistentRegionConfig

public ConsistentRegionConfig(int period)

Create a ConsistentRegionConfig.Trigger.PERIODIC consistent region configuration. The IBM Streams runtime will trigger a drain and checkpoint the region periodically approximately every period seconds.
Configuration values are set to the default values.

Parameters:

period - Trigger period in seconds.

Method Detail

operatorDriven

public static ConsistentRegionConfig operatorDriven()

Create a ConsistentRegionConfig.Trigger.OPERATOR_DRIVEN consistent region configuration. The source operator triggers drain and checkpoint cycles for the region.
Configuration values are set to the default values.

This is equivalent to ConsistentRegionConfig() but when used as an imported static method can produce clearer code:

 
 import static com.ibm.streamsx.topology.consistent.ConsistentRegionConfig.operatorDriven;
 ...
     stream.setConsistent(operatorDriven());
 
 

periodic

public static ConsistentRegionConfig periodic(int period)

Create a ConsistentRegionConfig.Trigger.PERIODIC consistent region configuration. The IBM Streams runtime will trigger a drain and checkpoint the region periodically approximately every period seconds.
Configuration values are set to the default values.

This is equivalent to ConsistentRegionConfig(int) but when used as an imported static method can produce clearer code:

 
 import static com.ibm.streamsx.topology.consistent.ConsistentRegionConfig.periodic;
 ...
     stream.setConsistent(periodic(30));
 
 

Parameters:

period - Trigger period in seconds.

getTrigger

public ConsistentRegionConfig.Trigger getTrigger()

Get the trigger type.

Returns:

trigger type.

getPeriod

public long getPeriod()

Get the trigger period.

Returns:

period if getTrigger() is ConsistentRegionConfig.Trigger.PERIODIC otherwise -1.

getTimeUnit

public java.util.concurrent.TimeUnit getTimeUnit()

Get the time unit for getPeriod(), getDrainTimeout() and getResetTimeout()().

Returns:

Time unit for this configuration.

getDrainTimeout

public long getDrainTimeout()

Get the drain timeout for this configuration.

Returns:

Drain timeout in units of getTimeUnit().

drainTimeout

public ConsistentRegionConfig drainTimeout(long drainTimeout)

Return a new configuration changing drainTimeout. A new configuration instance is returned that is a copy of this configuration with only drainTimeout changed.

stream.setConsistent(periodic(30).drainTimeout(5))

Parameters:

drainTimeout - Drain timeout to use in seconds, must be greater than 0.

Returns:

New configuration with drain timeout set to drainTimeout and the remaining values copied from this configuration.

getResetTimeout

public long getResetTimeout()

Get the reset timeout for this configuration.

Returns:

Reset timeout in units of getTimeUnit().

resetTimeout

public ConsistentRegionConfig resetTimeout(long resetTimeout)

Return a new configuration changing resetTimeout. A new configuration instance is returned that is a copy of this configuration with only resetTimeout changed.

stream.setConsistent(periodic(30).resetTimeout(15))

Parameters:

resetTimeout - Reset timeout to use in seconds, must be greater than 0.

Returns:

New configuration with reset timeout set to resetTimeout and the remaining values copied from this configuration.

getMaxConsecutiveResetAttempts

public int getMaxConsecutiveResetAttempts()

Get the maximum number of consecutive reset attempts.

Returns:

Maximum number of consecutive reset attempts.

maxConsecutiveResetAttempts

public ConsistentRegionConfig maxConsecutiveResetAttempts(int attempts)

Return a new configuration changing maxConsecutiveResetAttempts. A new configuration instance is returned that is a copy of this configuration with only maxConsecutiveResetAttempts changed.

stream.setConsistent(periodic(30).maxConsecutiveResetAttempts(7))

Parameters:

attempts - Maximum number of consecutive reset attempts, must be greater than 0.

Returns:

New configuration with maxConsecutiveResetAttempts set to attempts and the remaining values copied from this configuration.

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object