org.apache.hudi.common.util.queue

Enum DisruptorWaitStrategyType

java.lang.Object

java.lang.Enum<DisruptorWaitStrategyType>

org.apache.hudi.common.util.queue.DisruptorWaitStrategyType

All Implemented Interfaces:

Serializable, Comparable<DisruptorWaitStrategyType>

@EnumDescription(value="Strategy employed for making Disruptor Executor wait on a cursor.")
public enum DisruptorWaitStrategyType
extends Enum<DisruptorWaitStrategyType>

Enum for the type of waiting strategy in Disruptor Queue.

Enum Constant Summary

Enum Constants

Enum Constant and Description
BLOCKING_WAIT The BlockingWaitStrategy is the slowest of the available wait strategies, but is the most conservative with the respect to CPU usage and will give the most consistent behaviour across the widest variety of deployment options.
BUSY_SPIN_WAIT The `BusySpinWaitStrategy` is the highest performing WaitStrategy.
SLEEPING_WAIT Like the `BlockingWaitStrategy` the `SleepingWaitStrategy` it attempts to be conservative with CPU usage by using a simple busy wait loop.
YIELDING_WAIT The `YieldingWaitStrategy` is one of two WaitStrategies that can be used in low-latency systems.

Method Summary

Modifier and Type	Method and Description
static List<String>	getNames()
static DisruptorWaitStrategyType	valueOf(String name) Returns the enum constant of this type with the specified name.
static DisruptorWaitStrategyType[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

BLOCKING_WAIT

@EnumFieldDescription(value="The slowest of the available wait strategies. However, it is the most conservative with the respect to CPU usage and will give the most consistent behaviour across the widest variety of deployment options.")
public static final DisruptorWaitStrategyType BLOCKING_WAIT

The BlockingWaitStrategy is the slowest of the available wait strategies, but is the most conservative with the respect to CPU usage and will give the most consistent behaviour across the widest variety of deployment options.

SLEEPING_WAIT

@EnumFieldDescription(value="Like the `BLOCKING_WAIT` strategy, it attempts to be conservative with CPU usage by using a simple busy wait loop. The difference is that the `SLEEPING_WAIT` strategy uses a call to `LockSupport.parkNanos(1)` in the middle of the loop. On a typical Linux system this will pause the thread for around 60\u00b5s.")
public static final DisruptorWaitStrategyType SLEEPING_WAIT

Like the `BlockingWaitStrategy` the `SleepingWaitStrategy` it attempts to be conservative with CPU usage by using a simple busy wait loop. The difference is that the `SleepingWaitStrategy` uses a call to `LockSupport.parkNanos(1)` in the middle of the loop. On a typical Linux system this will pause the thread for around 60µs.

YIELDING_WAIT

@EnumFieldDescription(value="The `YIELDING_WAIT` strategy is one of two wait strategy that can be used in low-latency systems. It is designed for cases where there is an opportunity to burn CPU cycles with the goal of improving latency. The `YIELDING_WAIT` strategy will busy spin, waiting for the sequence to increment to the appropriate value. Inside the body of the loop `Thread#yield()` will be called allowing other queued threads to run. This is the recommended wait strategy when you need very high performance, and the number of `EventHandler` threads is lower than the total number of logical cores, such as when hyper-threading is enabled.")
public static final DisruptorWaitStrategyType YIELDING_WAIT

The `YieldingWaitStrategy` is one of two WaitStrategies that can be used in low-latency systems. It is designed for cases where there is the option to burn CPU cycles with the goal of improving latency. The `YieldingWaitStrategy` will busy spin, waiting for the sequence to increment to the appropriate value. Inside the body of the loop `Thread#yield()` will be called allowing other queued threads to run. This is the recommended wait strategy when you need very high performance, and the number of `EventHandler` threads is lower than the total number of logical cores, e.g. you have hyper-threading enabled.

BUSY_SPIN_WAIT

@EnumFieldDescription(value="The `BUSY_SPIN_WAIT` strategy is the highest performing wait strategy. Like the `YIELDING_WAIT` strategy, it can be used in low-latency systems, but puts the highest constraints on the deployment environment.")
public static final DisruptorWaitStrategyType BUSY_SPIN_WAIT

The `BusySpinWaitStrategy` is the highest performing WaitStrategy. Like the `YieldingWaitStrategy`, it can be used in low-latency systems, but puts the highest constraints on the deployment environment.

Method Detail

values

public static DisruptorWaitStrategyType[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (DisruptorWaitStrategyType c : DisruptorWaitStrategyType.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static DisruptorWaitStrategyType valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getNames

public static List<String> getNames()