org.apache.cassandra.locator

Class Replica

java.lang.Object

org.apache.cassandra.locator.Replica

All Implemented Interfaces:

java.lang.Comparable<Replica>

public final class Replica
extends java.lang.Object
implements java.lang.Comparable<Replica>

A Replica represents an owning node for a copy of a portion of the token ring. It consists of: - the logical token range that is being replicated (i.e. for the first logical replica only, this will be equal to one of its owned portions of the token ring; all other replicas will have this token range also) - an endpoint (IP and port) - whether the range is replicated in full, or transiently (CASSANDRA-14404) In general, it is preferred to use a Replica to a Range<Token>, particularly when users of the concept depend on knowledge of the full/transient status of the copy. That means you should avoid unwrapping and rewrapping these things and think hard about subtraction and such and what the result is WRT to transientness. Definitely avoid creating fake Replicas with misinformation about endpoints, ranges, or transientness.

Constructor Summary

Constructors

Constructor and Description
Replica(InetAddressAndPort endpoint, Range<Token> range, boolean full)
Replica(InetAddressAndPort endpoint, Token start, Token end, boolean full)

Method Summary

Modifier and Type	Method and Description
int	compareTo(Replica o)
boolean	contains(Range<Token> that)
Replica	decorateSubrange(Range<Token> subrange)
InetAddressAndPort	endpoint()
boolean	equals(java.lang.Object o)
static Replica	fullReplica(InetAddressAndPort endpoint, Range<Token> range)
static Replica	fullReplica(InetAddressAndPort endpoint, Token start, Token end)
int	hashCode()
boolean	intersectsOnRange(Replica replica)
boolean	isFull()
boolean	isSelf()
boolean	isTransient()
Range<Token>	range()
RangesAtEndpoint	subtractIgnoreTransientStatus(Range<Token> subtract) Don't use this method and ignore transient status unless you are explicitly handling it outside this method.
RangesAtEndpoint	subtractSameReplication(RangesAtEndpoint toSubtract) This is used exclusively in TokenMetadata to check if a portion of a range is already replicated by an endpoint so that we only mark as pending the portion that is either not replicated sufficiently (transient when we need full) or at all.
java.lang.String	toString()
static Replica	transientReplica(InetAddressAndPort endpoint, Range<Token> range)
static Replica	transientReplica(InetAddressAndPort endpoint, Token start, Token end)

Methods inherited from class java.lang.Object

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

Constructor Detail

Replica

public Replica(InetAddressAndPort endpoint,
               Range<Token> range,
               boolean full)

Replica

public Replica(InetAddressAndPort endpoint,
               Token start,
               Token end,
               boolean full)

Method Detail

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

compareTo

public int compareTo(Replica o)

Specified by:

compareTo in interface java.lang.Comparable<Replica>

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

endpoint

public final InetAddressAndPort endpoint()

isSelf

public boolean isSelf()

range

public Range<Token> range()

isFull

public final boolean isFull()

isTransient

public final boolean isTransient()

subtractSameReplication

public RangesAtEndpoint subtractSameReplication(RangesAtEndpoint toSubtract)

This is used exclusively in TokenMetadata to check if a portion of a range is already replicated by an endpoint so that we only mark as pending the portion that is either not replicated sufficiently (transient when we need full) or at all. If it's not replicated at all it needs to be pending because there is no data. If it's replicated but only transiently and we need to replicate it fully it must be marked as pending until it is available fully otherwise a read might treat this replica as full and not read from a full replica that has the data.

subtractIgnoreTransientStatus

public RangesAtEndpoint subtractIgnoreTransientStatus(Range<Token> subtract)

Don't use this method and ignore transient status unless you are explicitly handling it outside this method. This helper method is used by StorageService.calculateStreamAndFetchRanges to perform subtraction. It ignores transient status because it's already being handled in calculateStreamAndFetchRanges.

contains

public boolean contains(Range<Token> that)

intersectsOnRange

public boolean intersectsOnRange(Replica replica)

decorateSubrange

public Replica decorateSubrange(Range<Token> subrange)

fullReplica

public static Replica fullReplica(InetAddressAndPort endpoint,
                                  Range<Token> range)

fullReplica

public static Replica fullReplica(InetAddressAndPort endpoint,
                                  Token start,
                                  Token end)

transientReplica

public static Replica transientReplica(InetAddressAndPort endpoint,
                                       Range<Token> range)

transientReplica

public static Replica transientReplica(InetAddressAndPort endpoint,
                                       Token start,
                                       Token end)