Package org.apache.ignite.cache

Enum ReadRepairStrategy

java.lang.Object

java.lang.Enum<ReadRepairStrategy>

org.apache.ignite.cache.ReadRepairStrategy

All Implemented Interfaces:

Serializable, Comparable<ReadRepairStrategy>

public enum ReadRepairStrategy
extends Enum<ReadRepairStrategy>

Read repair strategies.

See Also:

for details.

Enum Constant Summary

Enum Constants

Enum Constant	Description
CHECK_ONLY	Only check will be performed.
LWW	Last write (the newest entry) wins.
PRIMARY	Value from the primary node wins.
RELATIVE_MAJORITY	The relative majority, any value found more times than any other wins.
REMOVE	Inconsistent entries will be removed.

Method Summary

Modifier and Type	Method	Description
static ReadRepairStrategy	fromString(String name)	Provides strategy by name.
static ReadRepairStrategy	valueOf(String name)	Returns the enum constant of this type with the specified name.
static ReadRepairStrategy[]	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

LWW

public static final ReadRepairStrategy LWW

Last write (the newest entry) wins.

May cause IgniteException when fix is impossible (unable to detect the newest entry):

• Null(s) found as well as non-null values for the same key.

  Null (missed entry) has no version, so, it can not be compared with the versioned entry.

• Entries with the same version have different values.

PRIMARY

public static final ReadRepairStrategy PRIMARY

Value from the primary node wins.

RELATIVE_MAJORITY

public static final ReadRepairStrategy RELATIVE_MAJORITY

The relative majority, any value found more times than any other wins.

Works for an even number of copies (which is typical of Ignite) instead of an absolute majority.

May cause IgniteException when it is unable to detect values found more times than any other.

For example, when 5 copies (4 backups) are given and value `A` is found twice, but `X`, `Y`, and `Z` only once, `A` wins. But, when `A` is found twice, as well as `B`, and `X` only once, the strategy is unable to determine the winner.

When 4 copies (3 backups) are given, any value found two or more times, when others are found only once, is the winner.

REMOVE

public static final ReadRepairStrategy REMOVE

Inconsistent entries will be removed.

CHECK_ONLY

public static final ReadRepairStrategy CHECK_ONLY

Only check will be performed.

Method Detail

values

public static ReadRepairStrategy[] 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 (ReadRepairStrategy c : ReadRepairStrategy.values())
    System.out.println(c);

Returns:

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

valueOf

public static ReadRepairStrategy 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

fromString

public static ReadRepairStrategy fromString(String name)

Provides strategy by name.

Parameters:

name - Text.

Returns:

Read Repair strategy.