Package org.apache.cassandra.config

Enum Class Config.PaxosStatePurging

java.lang.Object

java.lang.Enum<Config.PaxosStatePurging>

org.apache.cassandra.config.Config.PaxosStatePurging

All Implemented Interfaces:

Serializable, Comparable<Config.PaxosStatePurging>, Constable

Enclosing class:

Config

public static enum Config.PaxosStatePurging
extends Enum<Config.PaxosStatePurging>

Select the kind of paxos state purging to use. Migration to repaired is recommended, but requires that regular paxos repairs are performed (which by default run as part of incremental repair). Once migrated from legacy it is unsafe to return to legacy, but gc_grace mode may be used in its place and performs a very similar cleanup process. Should only be modified once paxos_variant = v2.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
gc_grace	Functionally similar to legacy, but the gc_grace expiry is applied at compaction and read time rather than using TTLs, so may be safely enabled at any point.
legacy	system.paxos records are written and garbage collected with TTLs.
repaired	Clears system.paxos records only once they are known to be persisted to a quorum of replica's base tables through the use of paxos repair.

Method Summary

Modifier and Type	Method	Description
static Config.PaxosStatePurging	fromBoolean(boolean enabled)
static Config.PaxosStatePurging	valueOf(String name)	Returns the enum constant of this class with the specified name.
static Config.PaxosStatePurging[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

legacy

public static final Config.PaxosStatePurging legacy

system.paxos records are written and garbage collected with TTLs. Unsafe to use with Commit consistency ANY. Once migrated from, cannot be migrated back to safely. Must use gc_grace or repaired instead, as TTLs will not have been set.

gc_grace

public static final Config.PaxosStatePurging gc_grace

Functionally similar to legacy, but the gc_grace expiry is applied at compaction and read time rather than using TTLs, so may be safely enabled at any point.

repaired

public static final Config.PaxosStatePurging repaired

Clears system.paxos records only once they are known to be persisted to a quorum of replica's base tables through the use of paxos repair. Requires that regular paxos repairs are performed on the cluster (which by default are included in incremental repairs if paxos_variant = v2). This setting permits the use of Commit consistency ANY or LOCAL_QUORUM without any loss of durability or consistency, saving 1 RT.

Method Details

values

public static Config.PaxosStatePurging[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

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

valueOf

public static Config.PaxosStatePurging valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (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 class has no constant with the specified name

NullPointerException - if the argument is null

fromBoolean

public static Config.PaxosStatePurging fromBoolean(boolean enabled)