Add new ConstantOccupancyWorkload to induce fragmentation in large object stores.

src/com/yahoo/ycsb/workloads/ConstantOccupancyWorkload.java

+/**
+ * Copyright (c) 2010 Yahoo! Inc. All rights reserved.                                                                                                                             
+ *                                                                                                                                                                                 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you                                                                                                             
+ * may not use this file except in compliance with the License. You                                                                                                                
+ * may obtain a copy of the License at                                                                                                                                             
+ *                                                                                                                                                                                 
+ * http://www.apache.org/licenses/LICENSE-2.0                                                                                                                                      
+ *                                                                                                                                                                                 
+ * Unless required by applicable law or agreed to in writing, software                                                                                                             
+ * distributed under the License is distributed on an "AS IS" BASIS,                                                                                                               
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or                                                                                                                 
+ * implied. See the License for the specific language governing                                                                                                                    
+ * permissions and limitations under the License. See accompanying                                                                                                                 
+ * LICENSE file.
+ */
+package com.yahoo.ycsb.workloads;
+
+import java.util.Properties;
+
+import com.yahoo.ycsb.WorkloadException;
+import com.yahoo.ycsb.Client;
+import com.yahoo.ycsb.generator.IntegerGenerator;
+
+/**
+ * A disk-fragmenting workload.
+ * <p>
+ * Properties to control the client:
+ * </p>
+ * <UL>
+ * <LI><b>disksize</b>: how many bytes of storage can the disk store? (default 100,000,000)
+ * <LI><b>occupancy</b>: what fraction of the available storage should be used? (default 0.9)
+ * <LI><b>requestdistribution</b>: what distribution should be used to select the records to operate on - uniform, zipfian or latest (default: histogram)
+ * </ul> 
+ *
+ *
+ * <p> See also:
+ * Russell Sears, Catharine van Ingen.
+ * <a href='https://database.cs.wisc.edu/cidr/cidr2007/papers/cidr07p34.pdf'>Fragmentation in Large Object Repositories</a>,
+ * CIDR 2006. [<a href='https://database.cs.wisc.edu/cidr/cidr2007/slides/p34-sears.ppt'>Presentation</a>]
+ * </p>
+ *
+ *
+ * @author sears
+ *
+ */
+public class ConstantOccupancyWorkload extends CoreWorkload {
+	long disksize;
+	long storageages;
+	IntegerGenerator objectsizes;
+	double occupancy;
+	
+	long object_count;
+	
+	public static final String STORAGE_AGE_PROPERTY = "storageages";
+	public static final long   STORAGE_AGE_PROPERTY_DEFAULT = 10;
+	
+	public static final String DISK_SIZE_PROPERTY = "disksize";
+	public static final long   DISK_SIZE_PROPERTY_DEFAULT = 100 * 1000 * 1000;
+	
+	public static final String OCCUPANCY_PROPERTY = "occupancy";
+	public static final double OCCUPANCY_PROPERTY_DEFAULT = 0.9;
+	
+	@Override
+	public void init(Properties p) throws WorkloadException
+	{
+		disksize    = Long.parseLong(    p.getProperty(DISK_SIZE_PROPERTY, DISK_SIZE_PROPERTY_DEFAULT+""));
+		storageages = Long.parseLong(    p.getProperty(STORAGE_AGE_PROPERTY, STORAGE_AGE_PROPERTY_DEFAULT+""));
+		occupancy   = Double.parseDouble(p.getProperty(OCCUPANCY_PROPERTY, OCCUPANCY_PROPERTY_DEFAULT+""));
+		
+		if(p.getProperty(Client.RECORD_COUNT_PROPERTY) != null ||
+		   p.getProperty(Client.INSERT_COUNT_PROPERTY) != null ||
+		   p.getProperty(Client.OPERATION_COUNT_PROPERTY) != null) {
+			System.err.println("Warning: record, insert or operation count was set prior to initting ConstantOccupancyWorkload.  Overriding old values.");
+		}
+		IntegerGenerator g = CoreWorkload.getFieldLengthGenerator(p);
+		System.out.println(g+ " mean " + g.mean());
+		double fieldsize = g.mean();
+		int fieldcount = Integer.parseInt(p.getProperty(FIELD_COUNT_PROPERTY, FIELD_COUNT_PROPERTY_DEFAULT));
+
+		object_count = (long)(occupancy * ((double)disksize / (fieldsize * (double)fieldcount)));
+		System.out.println("occupancy " + occupancy + " object count " + object_count);
+		p.setProperty(Client.RECORD_COUNT_PROPERTY, object_count+"");
+		p.setProperty(Client.OPERATION_COUNT_PROPERTY, (storageages*object_count)+"");
+		p.setProperty(Client.INSERT_COUNT_PROPERTY, object_count+"");
+
+		super.init(p);
+	}
+
+}