OptorSim源代码简要分析

==================================================================================================== OptimiserFactory类： abstract public class OptimiserFactory{……} 用以使得CE获得一个恰当的Optimiser的Object（根据数复制优化的选择项） private static final int SIMPLE_OPTIMISER = 1; private static final int LRU_OPTIMISER = 2; private static final int LFU_OPTIMISER = 3; private static final int ECO_MODEL_OPTIMISER = 4; private static final int ECO_MODEL_OPTIMISER_ZIPF_BASED = 5 Optimisable getOptimisable( GridSite site) 被RB使用，根据在配置文件中制定的数据复制优化选项产生 ==================================================================================================== LruOptimiser类： LruOptimiser extends ReplicatingOptimiser{……} LruOptimiser( GridSite site) { super(site);} 构造函数中指明了GridSite List chooseFilesToDelete( DataFile file, StorageElement se){ return se.filesToDelete(file);} ==================================================================================================== ReplicatingOptimiser类： abstract public class ReplicatingOptimiser extends SkelOptor{……} ReplicatingOptimiser (GridSite site ) { super(site);} DataFile[] getBestFile(String[] lfns, float[] fileFraction) * Always tries to replicate all the files specified by lfns to * the calling Computing Element's local Storage Element. * Replication will fail if a null is returned by the subclass' * chooseFileToDelete method. List chooseFilesToDelete( DataFile file, StorageElement se) * How to decide which files to delete in order to make space for DataFile file. * All subclasses must implement this using their own optimiser specific algorithms. ==================================================================================================== SkelOptor类： public class SkelOptor implements Optimisable{……} protected SkelOptor( GridSite site) { _site = site; _networkClient = new NetworkClient(); } protected GridSite _site; protected NetworkClient _networkClient; DataFile[] getBestFile{……} *A "standard" implementation of getBestFile. It simply looks at * the Replica Catalogue and current network status and returns the * replicas that will take the shortest time to access. float getAccessCost(String[] lfns,ComputingElement ce,float[] fileFraction) * Calculate aggregated network costs for a single computing element. * Uses network costs and the Replica Catalog to find the best replica * of each file and sums the access costs. ==================================================================================================== Optimisable接口: This interface must be implemented by all replica optimiser classes. * Each optimiser should define its own implementation of {@link #getBestFile}. * This is the method called whenever a file request is made. It determines * where the best replica of a file is and most implementations may perform * replication of files within this method. float getAccessCost(String[] lfn,ComputingElement ce,float[] fileFraction) 根据lfn数组中指出的文件逻辑名字，返回由ce访问他们的cost DataFile[] getBestFile(String[] lfn,float[] fileFraction); *Returns a {@link DataFile} array, possibly after some * replication has occurred. Computing Elements call this method * to find the best replicas of each file to access. ****************************************************************************************************************** ****************************************************************************************************************** ****************************************************************************************************************** ****************************************************************************************************************** =================================================================================================== ReplicaManager类： public class ReplicaManager{……} 提供了File的处理方法，是CE和optimisers间交互的接口。也是ReplicaCatalogue外包类，任何ReplicaCatalogue 的改变都要通过这个类实现。 private ReplicaCatalogue _rc; private final int ALL_OF_FILE=1; void registerEntry( DataFile file) { _rc.addFile( file); } 注册一个File入口 unregisterEntry( DataFile file) 取消一个file入口注册 DataFile replicateFile( DataFile source, StorageElement toSE) 拷贝source到指定的toSE上，并在ReplicaCatalogue中注册 void copyFile( DataFile source, StorageElement toSE) 拷贝source到指定的toSE上，但是不再ReplicaCatalogue中注册 deleteFile( DataFile file) 删除一个文件，调用ReplicaCatalogue::removeFile(……) 同时在储存file的SE上删除file =================================================================================================== ReplicaCatalogue类： class ReplicaCatalogue{……} * This class is a catalogue of files available on the Grid. Logical * File Names (strings representing a unique file ) are mapped * to the physical DataFiles (individual instances or replicas of each * file) spread around the Grid using a Hashtable. The keys are the * Logical File Names (string) and the values are Sets of DataFiles. * The ReplicaCatalogue is not used directly but is accessed via the * ReplicaManager which provides methods to for example copy a file * around the Grid or remove a file from the Grid private Hashtable _catalogue; public String getNextFile(); 返回下一个应该被处理的文件，这依赖于在配置文件中做出的选择。 ==================================================================================================== SequentialAccessGenerator类： public class SequentialAccessGenerator implements AccessPatternGenerator{……} private int _numFiles; private GridJob _job; private int _fileId=0; private int _fileCounter=0; 标志当前Job中已经处理了几个File,利用这个计数值和Job中的File数比较 SequentialAccessGenerator(GridJob gridJob, float fileSetFraction) {_job = gridJob;_numFiles = (int)( _job.size() * fileSetFraction); } String getNextFile() 返回下一个File的LFN ==================================================================================================== AccessPatternGeneratorFactory类： abstract public class AccessPatternGeneratorFactory{……} AccessPatternGenerator getAPGenerator(GridJob gridJob) {……} 返回正确的AccessPatternGenerator方式类对象 ****************************************************************************************************************** ********=********************************************************************************************************* ****************************************************************************************************************** ****************************************************************************************************************** ====================================================================================================== AccessHistoryStorageElement类： public class AccessHistoryStorageElement extends SimpleStorageElement{…… } * An extension of SimpleStorageElement which keeps a record of * file accesses. This is implemented as a {@link TreeMap} mapping * a {@link Date} to a {@link DataFile}. When a file is accessed on * the SE a new entry is added to the access history. Optimisation * algorithms in StorageElement classes that extend this class use * the recent access history to evaluate the relative values of * files stored on the SE. public AccessHistoryStorageElement(GridSite site, long capacity) {super(site, capacity);} 当SE上的一个File被访问，在history中一个新的入口被增加了 private TreeMap _accessHistory = new TreeMap