org.qbroker.common

Class LoadManager

java.lang.Object

org.qbroker.common.LoadManager

All Implemented Interfaces:

java.util.Comparator<java.lang.String>

public class LoadManager
extends java.lang.Object
implements java.util.Comparator<java.lang.String>

LoadManager manages generic work loads among the available nodes dynamically. A work load can be a service, a task or a set of resources. With the given nodes, LoadManager dynamically associates work loads to the available nodes according to the predefined policies and their weights. All the work loads are independent of each other. Each active work load must be allocated to one of the nodes. A node can be occupied by a number of the work loads. But any active work load must not occupy two different nodes at any given time. There are multiple combinations for the work load allocations. But LoadManager will always find the unique allocations. The allocation process is incremental and stateful. The result depends on its history and state.

A work load has three properties, type, weight and pattern. The type is either preferred or sticky. A preferred work load has its preferred node defined via the pattern. As long as there is a node matching the pattern is available, its allocation is always straight forward. If there is no preferred node available, it will be degraded to sticky. A sticky work load has no preference with any node. So its allocation is dynamically determined by the state and the policies. The weights of work loads are used to calculate the NORM of various allocation layouts. The most favorable allocation will have the minimum impact to the existing configuration and the maximum balance of work loads. The pattern is used to select preferable nodes. For any sticky work loads, its pattern should be set to a universal match.

A node has the only one property, capacity or maximum weight. The capacity determines the limit on total weight of the work loads.

Author:

yannanlu@yahoo.com

Field Summary

Fields

Modifier and Type	Field and Description
static int	LM_LOAD
static int	LM_NODE
static int	LOAD_COUNT
static int	LOAD_OID
static int	LOAD_PID
static int	LOAD_SIZE
static int	LOAD_STATUS
static int	LOAD_TIME
static int	LOAD_TYPE
static int	LOAD_WEIGHT
static int	NODE_COUNT
static int	NODE_GID
static int	NODE_MAX
static int	NODE_OPTION
static int	NODE_SIZE
static int	NODE_STATUS
static int	NODE_TIME
static int	NODE_WEIGHT
static int	TYPE_NONE
static int	TYPE_PREFERRED
static int	TYPE_STICKY

Constructor Summary

Constructors

Constructor and Description
LoadManager(java.lang.String name, int capacity)

Method Summary

Modifier and Type	Method and Description
int	add(java.lang.String key, int type, int weight, java.lang.String patternStr) returns the id of the load upon success or -1 otherwise
int	addNode(java.lang.String key, int gid, long max, java.lang.Object obj) returns id for the node upon success or -1 otherwise
Browser	browser() returns a Browser for all node IDs in the natural order
void	clear()
int	compare(java.lang.String a, java.lang.String b)
java.lang.Object	get(int id, int type)
int	getCapacity()
int	getID(java.lang.String key, int type)
java.lang.String[]	getList(int id) returns the sorted key list of all loads assigned to the node of id
long	getMTime()
java.lang.String	getName()
java.lang.String	getName(int id, int type)
int	getNodeId(int id) returns the node ID for the specified load of id
long	getNorm()
int	getSize(int type) returns the site of the specified type
int	getStatus(int id, int type) returns the status for the specified load of id
int	remove(java.lang.String key) returns the id of the load upon success or -1 otherwise
int[]	removeNode(java.lang.String key) returns an array containing unassigned work loads on the node
void	setStatus(int id, int status) sets the status for the specified load of id

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Detail

LOAD_OID

public static final int LOAD_OID

See Also:

Constant Field Values

LOAD_PID

public static final int LOAD_PID

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Constant Field Values

LOAD_TYPE

public static final int LOAD_TYPE

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Constant Field Values

LOAD_WEIGHT

public static final int LOAD_WEIGHT

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Constant Field Values

LOAD_STATUS

public static final int LOAD_STATUS

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Constant Field Values

LOAD_SIZE

public static final int LOAD_SIZE

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Constant Field Values

LOAD_COUNT

public static final int LOAD_COUNT

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Constant Field Values

LOAD_TIME

public static final int LOAD_TIME

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Constant Field Values

NODE_GID

public static final int NODE_GID

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Constant Field Values

NODE_WEIGHT

public static final int NODE_WEIGHT

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Constant Field Values

NODE_MAX

public static final int NODE_MAX

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Constant Field Values

NODE_STATUS

public static final int NODE_STATUS

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Constant Field Values

NODE_SIZE

public static final int NODE_SIZE

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Constant Field Values

NODE_COUNT

public static final int NODE_COUNT

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Constant Field Values

NODE_OPTION

public static final int NODE_OPTION

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Constant Field Values

NODE_TIME

public static final int NODE_TIME

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Constant Field Values

LM_NODE

public static final int LM_NODE

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Constant Field Values

LM_LOAD

public static final int LM_LOAD

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Constant Field Values

TYPE_NONE

public static final int TYPE_NONE

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Constant Field Values

TYPE_STICKY

public static final int TYPE_STICKY

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Constant Field Values

TYPE_PREFERRED

public static final int TYPE_PREFERRED

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Constant Field Values

Constructor Detail

LoadManager

public LoadManager(java.lang.String name,
                   int capacity)

Method Detail

addNode

public int addNode(java.lang.String key,
                   int gid,
                   long max,
                   java.lang.Object obj)

returns id for the node upon success or -1 otherwise

removeNode

public int[] removeNode(java.lang.String key)

returns an array containing unassigned work loads on the node

add

public int add(java.lang.String key,
               int type,
               int weight,
               java.lang.String patternStr)

returns the id of the load upon success or -1 otherwise

remove

public int remove(java.lang.String key)

returns the id of the load upon success or -1 otherwise

getSize

public int getSize(int type)

returns the site of the specified type

getStatus

public int getStatus(int id,
                     int type)

returns the status for the specified load of id

setStatus

public void setStatus(int id,
                      int status)

sets the status for the specified load of id

getID

public int getID(java.lang.String key,
                 int type)

get

public java.lang.Object get(int id,
                            int type)

getNodeId

public int getNodeId(int id)

returns the node ID for the specified load of id

getList

public java.lang.String[] getList(int id)

returns the sorted key list of all loads assigned to the node of id

getName

public java.lang.String getName(int id,
                                int type)

getName

public java.lang.String getName()

getCapacity

public int getCapacity()

getNorm

public long getNorm()

getMTime

public long getMTime()

compare

public int compare(java.lang.String a,
                   java.lang.String b)

Specified by:

compare in interface java.util.Comparator<java.lang.String>

browser

public Browser browser()

returns a Browser for all node IDs in the natural order

clear

public void clear()