ORG.oclc.opserve.opsmanager
Class LoadBalancer

java.lang.Object
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  +--java.util.AbstractCollection
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        +--java.util.AbstractList
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              +--java.util.Vector
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                    +--ORG.oclc.opserve.opsmanager.LoadBalancer

public class LoadBalancer

extends Vector

Provides the API to the load balancing files. These files contain one record per line. Each record is a comma delimited list containing the host id, hostname, server port, operations port and load factor.

See Also:

Serialized Form

Fields inherited from class java.util.Vector

capacityIncrement, elementCount, elementData

Fields inherited from class java.util.AbstractList

modCount

Constructor Summary

LoadBalancer()
Constructor that is used when writing a load balancing file

LoadBalancer(String loadDir, String serverType)
Reads the load balancing file and initializes a vector of potential servers.

Method Summary

void	addServer(String hostID, String hostName, int serverPort, int opPort, int loadFactor) Add a server to the load balancer list.
LoadedServer	leastLoadedServer() returns the least loaded server giving preference to servers on the local host within each load factor group.
void	reset() sets the next server to the lowest loaded server
void	writeLoadFile(String loadDir, String type) Generates a load balancing file.
void	writeLoadFile(String loadDir, String type, boolean readFirst) Generates a load balancing file.

Methods inherited from class java.util.Vector

add, add, addAll, addAll, addElement, capacity, clear, clone, contains, containsAll, copyInto, elementAt, elements, ensureCapacity, equals, firstElement, get, hashCode, indexOf, indexOf, insertElementAt, isEmpty, lastElement, lastIndexOf, lastIndexOf, remove, remove, removeAll, removeAllElements, removeElement, removeElementAt, removeRange, retainAll, set, setElementAt, setSize, size, subList, toArray, toArray, toString, trimToSize

Methods inherited from class java.util.AbstractList

iterator, listIterator, listIterator

Methods inherited from class java.lang.Object

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

Constructor Detail

LoadBalancer

public LoadBalancer(String loadDir,
                    String serverType)
             throws NoAvailableServerException

Reads the load balancing file and initializes a vector of potential servers.

Parameters:

loadDir - NFS mounted directory where load balancing file is

serverType - Name of load balancing file, less extension & path

Throws:

NoAvailableServerException - Indicates the file doesn't contain any active servers.

LoadBalancer

public LoadBalancer()

Constructor that is used when writing a load balancing file

Method Detail

leastLoadedServer

public LoadedServer leastLoadedServer()
                               throws NoAvailableServerException

returns the least loaded server giving preference to servers on the local host within each load factor group.

Returns:

the least loaded server

Throws:

NoAvailableServerException - Indicates the file doesn't contain any more active servers.

reset

public void reset()
           throws NoAvailableServerException

sets the next server to the lowest loaded server

Throws:

NoAvailableServerException - Indicates the file doesn't contain any active servers.

addServer

public void addServer(String hostID,
                      String hostName,
                      int serverPort,
                      int opPort,
                      int loadFactor)

Add a server to the load balancer list.

Parameters:

hostID - String used as a host id in the JaSSI URL.

hostName - Name of the host corresponding to the hostID

serverPort - Port used by server for normal operation

opPort - Port used by server for operations component

loadFactor - Measure of the load on this server

writeLoadFile

public void writeLoadFile(String loadDir,
                          String type)

Generates a load balancing file.

Parameters:

loadDir - Directory file is created in

type - Names file type.load

writeLoadFile

public void writeLoadFile(String loadDir,
                          String type,
                          boolean readFirst)

Generates a load balancing file.

Parameters:

loadDir - Directory file is created in

type - Names file type.load