io.atomix.copycat.server.cluster

Enum Member.Type

java.lang.Object

java.lang.Enum<Member.Type>

io.atomix.copycat.server.cluster.Member.Type

All Implemented Interfaces:

Serializable, Comparable<Member.Type>

Enclosing interface:

Member

public static enum Member.Type
extends Enum<Member.Type>

Indicates how the member participates in voting and replication.

The member type defines how a member interacts with the other members of the cluster and, more importantly, how the cluster leader interacts with the member server. Members can be promoted and demoted to alter member states. See the specific member types for descriptions of their implications on the cluster.

Enum Constant Summary

Enum Constants

Enum Constant and Description
ACTIVE Represents a full voting member of the Raft cluster which participates fully in leader election and replication algorithms.
INACTIVE Represents an inactive member.
PASSIVE Represents a member which participates in asynchronous replication but does not vote in elections or otherwise participate in the Raft consensus algorithm.
RESERVE Represents a member which does not participate in replication.

Method Summary

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

Methods inherited from class java.lang.Enum

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

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

INACTIVE

public static final Member.Type INACTIVE

Represents an inactive member.

The INACTIVE member type represents a member which does not participate in any communication and is not an active member of the cluster. This is typically the state of a member prior to joining or after leaving a cluster.

RESERVE

public static final Member.Type RESERVE

Represents a member which does not participate in replication.

The RESERVE member type is representative of a member that does not participate in any replication of state but only maintains contact with the cluster leader and is an active member of the Cluster. Typically, reserve members act as standby nodes which can be promoted to a PASSIVE or ACTIVE role when needed.

PASSIVE

public static final Member.Type PASSIVE

Represents a member which participates in asynchronous replication but does not vote in elections or otherwise participate in the Raft consensus algorithm.

The PASSIVE member type is representative of a member that receives state changes from follower nodes asynchronously. As state changes are committed via the ACTIVE Raft nodes, committed state changes are asynchronously replicated by followers to passive members. This allows passive members to maintain nearly up-to-date state with minimal impact on the performance of the Raft algorithm itself, and allows passive members to be quickly promoted to ACTIVE voting members if necessary.

ACTIVE

public static final Member.Type ACTIVE

Represents a full voting member of the Raft cluster which participates fully in leader election and replication algorithms.

The ACTIVE member type represents a full voting member of the Raft cluster. Active members participate in the Raft leader election and replication algorithms and can themselves be elected leaders.

Method Detail

values

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

Returns:

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

valueOf

public static Member.Type 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