Package org.apache.catalina.tribes.tipis

Class AbstractReplicatedMap<K,V>

java.lang.Object

org.apache.catalina.tribes.tipis.AbstractReplicatedMap<K,V>

Type Parameters:

K - The type of Key

V - The type of Value

All Implemented Interfaces:

java.io.Serializable, java.util.Map<K,V>, ChannelListener, RpcCallback, Heartbeat, MembershipListener

Direct Known Subclasses:

LazyReplicatedMap, ReplicatedMap

public abstract class AbstractReplicatedMap<K,V>
extends java.lang.Object
implements java.util.Map<K,V>, java.io.Serializable, RpcCallback, ChannelListener, MembershipListener, Heartbeat

An abstract replicated map implementation.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AbstractReplicatedMap.MapEntry<K,V>	Represents an entry in the replicated map, including metadata about its role (primary, backup, proxy).
static class	AbstractReplicatedMap.MapMessage	Represents a message sent between replicated map instances.
static interface	AbstractReplicatedMap.MapOwner	Interface for the owner of this replicated map.

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K extends java.lang.Object,V extends java.lang.Object>

Field Summary

Fields

Modifier and Type	Field	Description
protected long	accessTimeout	Since the map keeps internal membership this is the timeout for a ping message to be responded to If a remote map doesn't respond within this timeframe, its considered dead.
protected Channel	channel	Reference to the channel for sending messages
protected int	channelSendOptions	Our default send options
protected int	currentNode	The node we are currently backing up data to, this index will rotate on a round robin basis
static int	DEFAULT_INITIAL_CAPACITY	The default initial capacity - MUST be a power of two.
static float	DEFAULT_LOAD_FACTOR	The load factor used when none specified in constructor.
protected java.lang.ClassLoader[]	externalLoaders	External class loaders if serialization and deserialization is to be performed successfully.
protected java.util.concurrent.ConcurrentMap<K,AbstractReplicatedMap.MapEntry<K,V>>	innerMap	The underlying concurrent map storing entries.
protected byte[]	mapContextName	The Map context name makes this map unique, this allows us to have more than one map shared through one channel
protected java.util.HashMap<Member,java.lang.Long>	mapMembers	A list of members in our map
protected java.lang.String	mapname	Readable string of the mapContextName value
protected AbstractReplicatedMap.MapOwner	mapOwner	The owner of this map, ala a SessionManager for example
protected RpcChannel	rpcChannel	The RpcChannel to send RPC messages through
protected long	rpcTimeout	Timeout for RPC messages, how long we will wait for a reply
protected static StringManager	sm	The string manager for packaging specific messages.
protected java.lang.Object	stateMutex	Simple lock object for transfers
protected boolean	stateTransferred	Has the state been transferred

Constructor Summary

Constructors

Constructor	Description
AbstractReplicatedMap(AbstractReplicatedMap.MapOwner owner, Channel channel, long timeout, java.lang.String mapContextName, int initialCapacity, float loadFactor, int channelSendOptions, java.lang.ClassLoader[] cls, boolean terminate)	Creates a new map.

Method Summary

Modifier and Type	Method	Description
boolean	accept(java.io.Serializable msg, Member sender)	Accepts or rejects a message based on the map context.
void	breakdown()	Breaks down the map, removing all entries and closing channels.
protected void	broadcast(int msgtype, boolean rpc)	Helper method to broadcast a message to all members in a channel
void	clear()
void	clear(boolean notify)	Clears entries from the map.
boolean	containsKey(java.lang.Object key)	Returns true if the key has an entry in the map.
boolean	containsValue(java.lang.Object value)
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()	Returns a set view of the mappings contained in this map.
java.util.Set<java.util.Map.Entry<K,AbstractReplicatedMap.MapEntry<K,V>>>	entrySetFull()	Returns the entire contents of the map Map.Entry.getValue() will return a LazyReplicatedMap.MapEntry object containing all the information about the object.
boolean	equals(java.lang.Object o)	Checks if this map is equal to another object.
Member[]	excludeFromSet(Member[] mbrs, Member[] set)	Excludes members from the given set.
V	get(java.lang.Object key)
long	getAccessTimeout()	Gets the access timeout.
Channel	getChannel()	Gets the channel used for communication.
int	getChannelSendOptions()	Gets the channel send options.
java.lang.ClassLoader[]	getExternalLoaders()	Gets the external class loaders.
AbstractReplicatedMap.MapEntry<K,V>	getInternal(java.lang.Object key)	Gets the internal map entry for a key.
byte[]	getMapContextName()	Gets the map context name.
Member[]	getMapMembers()	Gets the current map members.
Member[]	getMapMembers(java.util.HashMap<Member,java.lang.Long> members)	Gets the map members from the given map.
Member[]	getMapMembersExcl(Member[] exclude)	Gets the map members excluding the given members.
AbstractReplicatedMap.MapOwner	getMapOwner()	Gets the map owner.
int	getNextBackupIndex()	Gets the next backup index using round-robin rotation.
Member	getNextBackupNode()	Gets the next backup node using round-robin rotation.
protected abstract int	getReplicateMessageType()	Gets the replicate message type.
RpcChannel	getRpcChannel()	Gets the RPC channel.
long	getRpcTimeout()	Gets the RPC timeout.
protected abstract int	getStateMessageType()	Gets the state message type.
java.lang.Object	getStateMutex()	Gets the state mutex object.
int	hashCode()	Returns the hash code for this map based on the map context name.
void	heartbeat()	Sends a heartbeat to all members in the cluster.
protected void	init(AbstractReplicatedMap.MapOwner owner, Channel channel, java.lang.String mapContextName, long timeout, int channelSendOptions, java.lang.ClassLoader[] cls, boolean terminate)	Initializes the map by creating the RPC channel, registering itself as a channel listener This method is also responsible for initiating the state transfer
boolean	inSet(Member m, Member[] set)	Checks if a member is in the given set.
boolean	isEmpty()	Checks if this map is empty.
boolean	isStateTransferred()	Checks if state has been transferred.
java.util.Set<K>	keySet()	Returns a set view of the keys contained in this map.
java.util.Set<K>	keySetFull()	Gets the complete set of keys in the map.
void	leftOver(java.io.Serializable msg, Member sender)	Handles a left over membership message.
void	mapMemberAdded(Member member)	Adds a member to this map.
void	memberAdded(Member member)	Called when a member is added to the channel.
protected void	memberAlive(Member member)	We have received a member alive notification
void	memberDisappeared(Member member)	Called when a member disappears from the channel.
void	messageReceived(java.io.Serializable msg, Member sender)	Handles a received message.
protected void	ping(long timeout)	Sends a ping out to all the members in the cluster, not just map members that this map is alive.
protected void	printMap(java.lang.String header)	Prints the contents of the map for debugging purposes.
protected abstract Member[]	publishEntryInfo(java.lang.Object key, java.lang.Object value)	Publish info about a map pair (key/value) to other nodes in the cluster.
V	put(K key, V value)	Puts a key-value pair into the map.
V	put(K key, V value, boolean notify)	Puts a key-value pair into the map.
void	putAll(java.util.Map<? extends K,? extends V> m)	Copies all mappings from the specified map to this map.
V	remove(java.lang.Object key)	Removes the entry for the specified key from the map.
V	remove(java.lang.Object key, boolean notify)	Removes the entry for the specified key from the map.
void	replicate(boolean complete)	This can be invoked by a periodic thread to replicate out any changes.
void	replicate(K key, boolean complete)	Replicates any changes to the object since the last time The object has to be primary, ie, if the object is a proxy or a backup, it will not be replicated
java.io.Serializable	replyRequest(java.io.Serializable msg, Member sender)	Handles a reply request message.
void	setAccessTimeout(long accessTimeout)	Sets the access timeout.
void	setChannelSendOptions(int channelSendOptions)	Sets the channel send options.
void	setExternalLoaders(java.lang.ClassLoader[] externalLoaders)	Sets the external class loaders.
void	setMapOwner(AbstractReplicatedMap.MapOwner mapOwner)	Sets the map owner.
int	size()	Returns the number of active entries in this map.
int	sizeFull()	Gets the complete size of the map.
void	transferState()	Transfers the current state from another map in the cluster.
java.util.Collection<V>	values()	Returns a collection view of the values contained in this map.
protected Member[]	wrap(Member m)	Helper methods, wraps a single member in an array

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Detail

sm

protected static final StringManager sm

The string manager for packaging specific messages.

DEFAULT_INITIAL_CAPACITY

public static final int DEFAULT_INITIAL_CAPACITY

The default initial capacity - MUST be a power of two.

See Also:

Constant Field Values

DEFAULT_LOAD_FACTOR

public static final float DEFAULT_LOAD_FACTOR

The load factor used when none specified in constructor.

See Also:

Constant Field Values

innerMap

protected final java.util.concurrent.ConcurrentMap<K,AbstractReplicatedMap.MapEntry<K,V>> innerMap

The underlying concurrent map storing entries.

rpcTimeout

protected transient long rpcTimeout

Timeout for RPC messages, how long we will wait for a reply

channel

protected transient Channel channel

Reference to the channel for sending messages

rpcChannel

protected transient RpcChannel rpcChannel

The RpcChannel to send RPC messages through

mapContextName

protected transient byte[] mapContextName

The Map context name makes this map unique, this allows us to have more than one map shared through one channel

stateTransferred

protected transient boolean stateTransferred

Has the state been transferred

stateMutex

protected final transient java.lang.Object stateMutex

Simple lock object for transfers

mapMembers

protected final transient java.util.HashMap<Member,java.lang.Long> mapMembers

A list of members in our map

channelSendOptions

protected transient int channelSendOptions

Our default send options

mapOwner

protected transient AbstractReplicatedMap.MapOwner mapOwner

The owner of this map, ala a SessionManager for example

externalLoaders

protected transient java.lang.ClassLoader[] externalLoaders

External class loaders if serialization and deserialization is to be performed successfully.

currentNode

protected transient int currentNode

The node we are currently backing up data to, this index will rotate on a round robin basis

accessTimeout

protected transient long accessTimeout

Since the map keeps internal membership this is the timeout for a ping message to be responded to If a remote map doesn't respond within this timeframe, its considered dead.

mapname

protected transient java.lang.String mapname

Readable string of the mapContextName value

Constructor Detail

AbstractReplicatedMap

public AbstractReplicatedMap(AbstractReplicatedMap.MapOwner owner,
                             Channel channel,
                             long timeout,
                             java.lang.String mapContextName,
                             int initialCapacity,
                             float loadFactor,
                             int channelSendOptions,
                             java.lang.ClassLoader[] cls,
                             boolean terminate)

Creates a new map.

Parameters:

owner - The map owner

channel - The channel to use for communication

timeout - long - timeout for RPC messages

mapContextName - String - unique name for this map, to allow multiple maps per channel

initialCapacity - int - the size of this map, see HashMap

loadFactor - float - load factor, see HashMap

channelSendOptions - Send options

cls - - a list of classloaders to be used for deserialization of objects.

terminate - - Flag for whether to terminate this map that failed to start.

Method Detail

getStateMessageType

protected abstract int getStateMessageType()

Gets the state message type.

Returns:

the state message type

getReplicateMessageType

protected abstract int getReplicateMessageType()

Gets the replicate message type.

Returns:

the replicate message type

wrap

protected Member[] wrap(Member m)

Helper methods, wraps a single member in an array

Parameters:

m - Member

Returns:

Member[]

init

protected void init(AbstractReplicatedMap.MapOwner owner,
                    Channel channel,
                    java.lang.String mapContextName,
                    long timeout,
                    int channelSendOptions,
                    java.lang.ClassLoader[] cls,
                    boolean terminate)

Initializes the map by creating the RPC channel, registering itself as a channel listener This method is also responsible for initiating the state transfer

Parameters:

owner - Object

channel - Channel

mapContextName - String

timeout - long

channelSendOptions - int

cls - ClassLoader[]

terminate - - Flag for whether to terminate this map that failed to start.

ping

protected void ping(long timeout)
             throws ChannelException

Sends a ping out to all the members in the cluster, not just map members that this map is alive.

Parameters:

timeout - long

Throws:

ChannelException - Send error

memberAlive

protected void memberAlive(Member member)

We have received a member alive notification

Parameters:

member - Member

broadcast

protected void broadcast(int msgtype,
                         boolean rpc)
                  throws ChannelException

Helper method to broadcast a message to all members in a channel

Parameters:

msgtype - int

rpc - boolean

Throws:

ChannelException - Send error

breakdown

public void breakdown()

Breaks down the map, removing all entries and closing channels.

hashCode

public int hashCode()

Returns the hash code for this map based on the map context name.

Specified by:

hashCode in interface java.util.Map<K,V>

Overrides:

hashCode in class java.lang.Object

Returns:

the hash code

equals

public boolean equals(java.lang.Object o)

Checks if this map is equal to another object.

Specified by:

equals in interface java.util.Map<K,V>

Overrides:

equals in class java.lang.Object

Parameters:

o - the object to compare

Returns:

true if the maps have the same context name

getMapMembers

public Member[] getMapMembers(java.util.HashMap<Member,java.lang.Long> members)

Gets the map members from the given map.

Parameters:

members - The member map

Returns:

an array of members

getMapMembers

public Member[] getMapMembers()

Gets the current map members.

Returns:

an array of members

getMapMembersExcl

public Member[] getMapMembersExcl(Member[] exclude)

Gets the map members excluding the given members.

Parameters:

exclude - Members to exclude from the result

Returns:

an array of members excluding the specified ones

replicate

public void replicate(K key,
                      boolean complete)

Replicates any changes to the object since the last time The object has to be primary, ie, if the object is a proxy or a backup, it will not be replicated

Parameters:

key - The object to replicate

complete - - if set to true, the object is replicated to its backup if set to false, only objects that implement ReplicatedMapEntry and the isDirty() returns true will be replicated

replicate

public void replicate(boolean complete)

This can be invoked by a periodic thread to replicate out any changes. For maps that don't store objects that implement ReplicatedMapEntry, this method should be used infrequently to avoid large amounts of data transfer

Parameters:

complete - boolean

transferState

public void transferState()

Transfers the current state from another map in the cluster.

replyRequest

public java.io.Serializable replyRequest(java.io.Serializable msg,
                                         Member sender)

Handles a reply request message.

Specified by:

replyRequest in interface RpcCallback

Parameters:

msg - The message

sender - The sender

Returns:

the reply message or null

leftOver

public void leftOver(java.io.Serializable msg,
                     Member sender)

Handles a left over membership message.

Specified by:

leftOver in interface RpcCallback

Parameters:

msg - The message

sender - The sender

messageReceived

public void messageReceived(java.io.Serializable msg,
                            Member sender)

Handles a received message.

Specified by:

messageReceived in interface ChannelListener

Parameters:

msg - The message

sender - The sender

accept

public boolean accept(java.io.Serializable msg,
                      Member sender)

Accepts or rejects a message based on the map context.

Specified by:

accept in interface ChannelListener

Parameters:

msg - The message

sender - The sender

Returns:

true if the message is accepted

mapMemberAdded

public void mapMemberAdded(Member member)

Adds a member to this map.

Parameters:

member - The member to add

inSet

public boolean inSet(Member m,
                     Member[] set)

Checks if a member is in the given set.

Parameters:

m - The member to check

set - The set to check against

Returns:

true if the member is in the set

excludeFromSet

public Member[] excludeFromSet(Member[] mbrs,
                               Member[] set)

Excludes members from the given set.

Parameters:

mbrs - The members to exclude

set - The set to exclude from

Returns:

The resulting set after exclusion

memberAdded

public void memberAdded(Member member)

Called when a member is added to the channel.

Specified by:

memberAdded in interface MembershipListener

Parameters:

member - The member that was added

memberDisappeared

public void memberDisappeared(Member member)

Called when a member disappears from the channel.

Specified by:

memberDisappeared in interface MembershipListener

Parameters:

member - The member that disappeared

See Also:

Member.SHUTDOWN_PAYLOAD

getNextBackupIndex

public int getNextBackupIndex()

Gets the next backup index using round-robin rotation.

Returns:

The next backup index, or -1 if no members exist

getNextBackupNode

public Member getNextBackupNode()

Gets the next backup node using round-robin rotation.

Returns:

The next backup node, or null if no members exist

publishEntryInfo

protected abstract Member[] publishEntryInfo(java.lang.Object key,
                                             java.lang.Object value)
                                      throws ChannelException

Publish info about a map pair (key/value) to other nodes in the cluster.

Parameters:

key - Object

value - Object

Returns:

Member - the backup node

Throws:

ChannelException - Cluster error

heartbeat

public void heartbeat()

Sends a heartbeat to all members in the cluster.

Specified by:

heartbeat in interface Heartbeat

remove

public V remove(java.lang.Object key)

Removes the entry for the specified key from the map.

Specified by:

remove in interface java.util.Map<K,V>

Parameters:

key - The key to remove

Returns:

The previous value associated with the key, or null

remove

public V remove(java.lang.Object key,
                boolean notify)

Removes the entry for the specified key from the map.

Parameters:

key - The key to remove

notify - Whether to notify other members

Returns:

The previous value associated with the key, or null

getInternal

public AbstractReplicatedMap.MapEntry<K,V> getInternal(java.lang.Object key)

Gets the internal map entry for a key.

Parameters:

key - The key

Returns:

the internal map entry, or null if not found

get

public V get(java.lang.Object key)

Specified by:

get in interface java.util.Map<K,V>

printMap

protected void printMap(java.lang.String header)

Prints the contents of the map for debugging purposes.

Parameters:

header - Header string to print before the map contents

containsKey

public boolean containsKey(java.lang.Object key)

Returns true if the key has an entry in the map. The entry can be a proxy or a backup entry, invoking get(key) will make this entry primary for the group

Specified by:

containsKey in interface java.util.Map<K,V>

Parameters:

key - Object

Returns:

boolean

put

public V put(K key,
             V value)

Puts a key-value pair into the map.

Specified by:

put in interface java.util.Map<K,V>

Parameters:

key - The key

value - The value

Returns:

The previous value associated with the key, or null

put

public V put(K key,
             V value,
             boolean notify)

Puts a key-value pair into the map.

Parameters:

key - The key

value - The value

notify - Whether to notify other members

Returns:

The previous value associated with the key, or null

putAll

public void putAll(java.util.Map<? extends K,? extends V> m)

Copies all mappings from the specified map to this map.

Specified by:

putAll in interface java.util.Map<K,V>

Parameters:

m - The map whose mappings are to be copied

clear

public void clear()

Specified by:

clear in interface java.util.Map<K,V>

clear

public void clear(boolean notify)

Clears entries from the map.

Parameters:

notify - Whether to notify other members

containsValue

public boolean containsValue(java.lang.Object value)

Specified by:

containsValue in interface java.util.Map<K,V>

entrySetFull

public java.util.Set<java.util.Map.Entry<K,AbstractReplicatedMap.MapEntry<K,V>>> entrySetFull()

Returns the entire contents of the map Map.Entry.getValue() will return a LazyReplicatedMap.MapEntry object containing all the information about the object.

Returns:

Set

keySetFull

public java.util.Set<K> keySetFull()

Gets the complete set of keys in the map.

Returns:

The complete set of keys

sizeFull

public int sizeFull()

Gets the complete size of the map.

Returns:

The complete size of the map

entrySet

public java.util.Set<java.util.Map.Entry<K,V>> entrySet()

Returns a set view of the mappings contained in this map.

Specified by:

entrySet in interface java.util.Map<K,V>

Returns:

a set view of the mappings

keySet

public java.util.Set<K> keySet()

Returns a set view of the keys contained in this map.

Specified by:

keySet in interface java.util.Map<K,V>

Returns:

a set view of the keys

size

public int size()

Returns the number of active entries in this map.

Specified by:

size in interface java.util.Map<K,V>

Returns:

the number of active entries

isEmpty

public boolean isEmpty()

Checks if this map is empty.

Specified by:

isEmpty in interface java.util.Map<K,V>

Returns:

true if the map is empty

values

public java.util.Collection<V> values()

Returns a collection view of the values contained in this map.

Specified by:

values in interface java.util.Map<K,V>

Returns:

a collection view of the values

getChannel

public Channel getChannel()

Gets the channel used for communication.

Returns:

the channel

getMapContextName

public byte[] getMapContextName()

Gets the map context name.

Returns:

the map context name as bytes

getRpcChannel

public RpcChannel getRpcChannel()

Gets the RPC channel.

Returns:

the RPC channel

getRpcTimeout

public long getRpcTimeout()

Gets the RPC timeout.

Returns:

the RPC timeout in milliseconds

getStateMutex

public java.lang.Object getStateMutex()

Gets the state mutex object.

Returns:

the state mutex

isStateTransferred

public boolean isStateTransferred()

Checks if state has been transferred.

Returns:

true if state has been transferred

getMapOwner

public AbstractReplicatedMap.MapOwner getMapOwner()

Gets the map owner.

Returns:

the map owner

getExternalLoaders

public java.lang.ClassLoader[] getExternalLoaders()

Gets the external class loaders.

Returns:

the external class loaders

getChannelSendOptions

public int getChannelSendOptions()

Gets the channel send options.

Returns:

the channel send options

getAccessTimeout

public long getAccessTimeout()

Gets the access timeout.

Returns:

the access timeout in milliseconds

setMapOwner

public void setMapOwner(AbstractReplicatedMap.MapOwner mapOwner)

Sets the map owner.

Parameters:

mapOwner - The map owner

setExternalLoaders

public void setExternalLoaders(java.lang.ClassLoader[] externalLoaders)

Sets the external class loaders.

Parameters:

externalLoaders - The external class loaders

setChannelSendOptions

public void setChannelSendOptions(int channelSendOptions)

Sets the channel send options.

Parameters:

channelSendOptions - The channel send options

setAccessTimeout

public void setAccessTimeout(long accessTimeout)

Sets the access timeout.

Parameters:

accessTimeout - The access timeout in milliseconds