diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
index 91bdca6..870aae4 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixStorageProperties.java
@@ -5,8 +5,8 @@
     private static final String STORAGE_BUFFERCACHE_PAGESIZE_KEY = "storage.buffercache.pagesize";
     private static int STORAGE_BUFFERCACHE_PAGESIZE_DEFAULT = (32 << 10); // 32KB
 
-    private static final String STORAGE_BUFFERCACHE_NUMPAGES_KEY = "storage.buffercache.numpages";
-    private static final int STORAGE_BUFFERCACHE_NUMPAGES_DEFAULT = 1024;
+    private static final String STORAGE_BUFFERCACHE_SIZE_KEY = "storage.buffercache.size";
+    private static final long STORAGE_BUFFERCACHE_SIZE_DEFAULT = (32 << 20); // 32 MB
 
     private static final String STORAGE_BUFFERCACHE_MAXOPENFILES_KEY = "storage.buffercache.maxopenfiles";
     private static int STORAGE_BUFFERCACHE_MAXOPENFILES_DEFAULT = Integer.MAX_VALUE;
@@ -15,7 +15,7 @@
     private static final int STORAGE_MEMORYCOMPONENT_PAGESIZE_DEFAULT = (32 << 10); // 32KB
 
     private static final String STORAGE_MEMORYCOMPONENT_NUMPAGES_KEY = "storage.memorycomponent.numpages";
-    private static final int STORAGE_MEMORYCOMPONENT_NUMPAGES_DEFAULT = 2048; // ... so 64MB components
+    private static final int STORAGE_MEMORYCOMPONENT_NUMPAGES_DEFAULT = 1024; // ... so 32MB components
 
     private static final String STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_KEY = "storage.memorycomponent.globalbudget";
     private static final long STORAGE_MEMORYCOMPONENT_GLOBALBUDGET_DEFAULT = (1 << 30); // 1GB
@@ -35,9 +35,13 @@
                 PropertyInterpreters.getIntegerPropertyInterpreter());
     }
 
+    public long getBufferCacheSize() {
+        return accessor.getProperty(STORAGE_BUFFERCACHE_SIZE_KEY, STORAGE_BUFFERCACHE_SIZE_DEFAULT,
+                PropertyInterpreters.getLongPropertyInterpreter());
+    }
+    
     public int getBufferCacheNumPages() {
-        return accessor.getProperty(STORAGE_BUFFERCACHE_NUMPAGES_KEY, STORAGE_BUFFERCACHE_NUMPAGES_DEFAULT,
-                PropertyInterpreters.getIntegerPropertyInterpreter());
+        return (int) (getBufferCacheSize() / getBufferCachePageSize());
     }
 
     public int getBufferCacheMaxOpenFiles() {
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixTransactionProperties.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixTransactionProperties.java
index d97e53b..0b6ea85 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixTransactionProperties.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/config/AsterixTransactionProperties.java
@@ -1,6 +1,9 @@
 package edu.uci.ics.asterix.common.config;
 
 public class AsterixTransactionProperties extends AbstractAsterixProperties {
+    private static final String TXN_LOG_DIRECTORY_KEY = "txn.log.directory";
+    private static final String TXN_LOG_DIRECTORY_DEFAULT = "asterix_logs/";
+    
     private static final String TXN_LOG_BUFFER_NUMPAGES_KEY = "txn.log.buffer.numpages";
     private static int TXN_LOG_BUFFER_NUMPAGES_DEFAULT = 8;
 
@@ -9,25 +12,46 @@
 
     private static final String TXN_LOG_PARTITIONSIZE_KEY = "txn.log.partitionsize";
     private static final long TXN_LOG_PARTITIONSIZE_DEFAULT = (2 << 30); // 2GB
+    
+    private static final String TXN_LOG_DISKSECTORSIZE_KEY = "txn.log.disksectorsize";
+    private static final int TXN_LOG_DISKSECTORSIZE_DEFAULT = 4096;
 
     private static final String TXN_LOG_GROUPCOMMITINTERVAL_KEY = "txn.log.groupcommitinterval";
-    private static int TXN_LOG_GROUPCOMMITINTERVAL_DEFAULT = 200; // 200ms
+    private static int TXN_LOG_GROUPCOMMITINTERVAL_DEFAULT = 10; // 0.1ms
 
     private static final String TXN_LOG_CHECKPOINT_LSNTHRESHOLD_KEY = "txn.log.checkpoint.lsnthreshold";
     private static final int TXN_LOG_CHECKPOINT_LSNTHRESHOLD_DEFAULT = (64 << 20); // 64M
 
     private static final String TXN_LOG_CHECKPOINT_POLLFREQUENCY_KEY = "txn.log.checkpoint.pollfrequency";
     private static int TXN_LOG_CHECKPOINT_POLLFREQUENCY_DEFAULT = 120; // 120s
+    
+    private static final String TXN_LOG_CHECKPOINT_HISTORY_KEY = "txn.log.checkpoint.history";
+    private static int TXN_LOG_CHECKPOINT_HISTORY_DEFAULT = 0;
 
     private static final String TXN_LOCK_ESCALATIONTHRESHOLD_KEY = "txn.lock.escalationthreshold";
     private static int TXN_LOCK_ESCALATIONTHRESHOLD_DEFAULT = 1000;
 
     private static final String TXN_LOCK_SHRINKTIMER_KEY = "txn.lock.shrinktimer";
-    private static int TXN_LOCK_SHRINKTIMER_DEFAULT = 120000; // 2m
+    private static int TXN_LOCK_SHRINKTIMER_DEFAULT = 5000; // 5s
+    
+    private static final String TXN_LOCK_TIMEOUT_WAITTHRESHOLD_KEY = "txn.lock.timeout.waitthreshold";
+    private static final int TXN_LOCK_TIMEOUT_WAITTHRESHOLD_DEFAULT = 60000; // 60s
+    
+    private static final String TXN_LOCK_TIMEOUT_SWEEPTHRESHOLD_KEY = "txn.lock.timeout.sweepthreshold";
+    private static final int TXN_LOCK_TIMEOUT_SWEEPTHRESHOLD_DEFAULT = 10000; // 10s
 
     public AsterixTransactionProperties(AsterixPropertiesAccessor accessor) {
         super(accessor);
     }
+    
+    public String getLogDirectory() {
+        String logDirectory = accessor.getProperty(TXN_LOG_DIRECTORY_KEY, TXN_LOG_DIRECTORY_DEFAULT,
+                PropertyInterpreters.getStringPropertyInterpreter());
+        if (!logDirectory.endsWith("/")) {
+            logDirectory += "/";
+        }
+        return logDirectory;
+    }
 
     public int getLogBufferNumPages() {
         return accessor.getProperty(TXN_LOG_BUFFER_NUMPAGES_KEY, TXN_LOG_BUFFER_NUMPAGES_DEFAULT,
@@ -43,6 +67,11 @@
         return accessor.getProperty(TXN_LOG_PARTITIONSIZE_KEY, TXN_LOG_PARTITIONSIZE_DEFAULT,
                 PropertyInterpreters.getLongPropertyInterpreter());
     }
+    
+    public int getLogDiskSectorSize() {
+        return accessor.getProperty(TXN_LOG_DISKSECTORSIZE_KEY, TXN_LOG_DISKSECTORSIZE_DEFAULT,
+                PropertyInterpreters.getIntegerPropertyInterpreter());
+    }
 
     public int getGroupCommitInterval() {
         return accessor.getProperty(TXN_LOG_GROUPCOMMITINTERVAL_KEY, TXN_LOG_GROUPCOMMITINTERVAL_DEFAULT,
@@ -59,6 +88,11 @@
                 PropertyInterpreters.getIntegerPropertyInterpreter());
     }
 
+    public int getCheckpointHistory() {
+        return accessor.getProperty(TXN_LOG_CHECKPOINT_HISTORY_KEY, TXN_LOG_CHECKPOINT_HISTORY_DEFAULT,
+                PropertyInterpreters.getIntegerPropertyInterpreter());
+    }
+    
     public int getEntityToDatasetLockEscalationThreshold() {
         return accessor.getProperty(TXN_LOCK_ESCALATIONTHRESHOLD_KEY, TXN_LOCK_ESCALATIONTHRESHOLD_DEFAULT,
                 PropertyInterpreters.getIntegerPropertyInterpreter());
@@ -68,5 +102,15 @@
         return accessor.getProperty(TXN_LOCK_SHRINKTIMER_KEY, TXN_LOCK_SHRINKTIMER_DEFAULT,
                 PropertyInterpreters.getIntegerPropertyInterpreter());
     }
+    
+    public int getTimeoutWaitThreshold() {
+        return accessor.getProperty(TXN_LOCK_TIMEOUT_WAITTHRESHOLD_KEY, TXN_LOCK_TIMEOUT_WAITTHRESHOLD_DEFAULT,
+                PropertyInterpreters.getIntegerPropertyInterpreter());
+    }
+    
+    public int getTimeoutSweepThreshold() {
+        return accessor.getProperty(TXN_LOCK_TIMEOUT_SWEEPTHRESHOLD_KEY, TXN_LOCK_TIMEOUT_SWEEPTHRESHOLD_DEFAULT,
+                PropertyInterpreters.getIntegerPropertyInterpreter());
+    }
 
 }
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/transactions/LogManagerProperties.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/transactions/LogManagerProperties.java
index f92b977..9387687 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/transactions/LogManagerProperties.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/transactions/LogManagerProperties.java
@@ -25,8 +25,6 @@
     public static final int LOG_MAGIC_NUMBER = 123456789;
     public static final String LOG_DIR_SUFFIX = ".txnLogDir";
     private static final String DEFAULT_LOG_FILE_PREFIX = "asterix_transaction_log";
-    private static final String DEFAULT_LOG_DIRECTORY = "asterix_logs/";
-    private static final int DEFAULT_DISK_SECTOR_SIZE = 4096;
 
     // follow the naming convention <logFilePrefix>_<number> where number starts from 0
     private final String logFilePrefix;
@@ -51,14 +49,14 @@
         this.logPageSize = txnProperties.getLogBufferPageSize();
         this.numLogPages = txnProperties.getLogBufferNumPages();
         long logPartitionSize = txnProperties.getLogPartitionSize();
-        this.logDir = DEFAULT_LOG_DIRECTORY + nodeId;
+        this.logDir = txnProperties.getLogDirectory() + nodeId;
         this.logFilePrefix = DEFAULT_LOG_FILE_PREFIX;
         this.groupCommitWaitPeriod = txnProperties.getGroupCommitInterval();
 
         this.logBufferSize = logPageSize * numLogPages;
         //make sure that the log partition size is the multiple of log buffer size.
         this.logPartitionSize = (logPartitionSize / logBufferSize) * logBufferSize;
-        this.diskSectorSize = DEFAULT_DISK_SECTOR_SIZE;
+        this.diskSectorSize = txnProperties.getLogDiskSectorSize();
     }
 
     public long getLogPartitionSize() {
diff --git a/asterix-installer/src/main/resources/conf/asterix-configuration.xml b/asterix-installer/src/main/resources/conf/asterix-configuration.xml
index bb7b9fb..7ee7e88 100644
--- a/asterix-installer/src/main/resources/conf/asterix-configuration.xml
+++ b/asterix-installer/src/main/resources/conf/asterix-configuration.xml
@@ -22,10 +22,11 @@
 	</property>
 
 	<property>
-		<name>storage.buffercache.numpages</name>
-		<value>1024</value>
-		<description>The number of pages allocated to the disk buffer cache.
-			(Default = "1024")
+		<name>storage.buffercache.size</name>
+		<value>33554432</value>
+		<description>The size of memory allocated to the disk buffer cache.
+			The value should be a multiple of the buffer cache page size(Default
+			= "33554432" // 32MB)
 		</description>
 	</property>
 
@@ -47,15 +48,15 @@
 
 	<property>
 		<name>storage.memorycomponent.numpages</name>
-		<value>4096</value>
+		<value>1024</value>
 		<description>The number of pages to allocate for a memory component.
-			(Default = 4096)
+			(Default = 1024)
 		</description>
 	</property>
 
 	<property>
 		<name>storage.memorycomponent.globalbudget</name>
-		<value>263435456</value>
+		<value>1073741824</value>
 		<description>The total size of memory in bytes that the sum of all
 			open memory
 			components cannot exceed. (Default = "1073741824" // 1GB)
@@ -79,6 +80,14 @@
 	</property>
 
 	<property>
+		<name>txn.log.directory</name>
+		<value>asterix_logs/</value>
+		<description>The directory location for transaction logs. (Default =
+			"asterix_logs/")
+		</description>
+	</property>
+
+	<property>
 		<name>txn.log.buffer.numpages</name>
 		<value>8</value>
 		<description>The number of in-memory log buffer pages. (Default = "8")
@@ -103,10 +112,17 @@
 	</property>
 
 	<property>
+		<name>txn.log.disksectorsize</name>
+		<value>4096</value>
+		<description>The size of a disk sector. (Default = "4096")
+		</description>
+	</property>
+
+	<property>
 		<name>txn.log.groupcommitinterval</name>
 		<value>1</value>
 		<description>The group commit wait time in milliseconds. (Default =
-			"200" // 2ms)
+			"10" // 0.1ms)
 		</description>
 	</property>
 
@@ -127,6 +143,14 @@
 	</property>
 
 	<property>
+		<name>txn.log.checkpoint.history</name>
+		<value>0</value>
+		<description>The number of old log partition files to keep before
+			discarding. (Default = "0")
+		</description>
+	</property>
+
+	<property>
 		<name>txn.lock.escalationthreshold</name>
 		<value>1000</value>
 		<description>The number of entity level locks that need to be acquired
@@ -137,9 +161,26 @@
 
 	<property>
 		<name>txn.lock.shrinktimer</name>
-		<value>120000</value>
+		<value>5000</value>
 		<description>The time in milliseconds to wait before deallocating
-			unused lock manager memory. (Default = "120000" // 120s)
+			unused lock manager memory. (Default = "5000" // 5s)
+		</description>
+	</property>
+
+	<property>
+		<name>txn.lock.timeout.waitthreshold</name>
+		<value>60000</value>
+		<description>The time in milliseconds to wait before labeling a
+			transaction which has been waiting for a lock timed-out. (Default =
+			"60000" // 60s)
+		</description>
+	</property>
+
+	<property>
+		<name>txn.lock.timeout.sweepthreshold</name>
+		<value>10000</value>
+		<description>The time in milliseconds the timeout thread waits between
+			sweeps to detect timed-out transactions. (Default = "10000" // 10s)
 		</description>
 	</property>
 
@@ -176,8 +217,8 @@
 
 	<property>
 		<name>api.port</name>
-		<value>19101</value>
-		<description>The port for the ASTERIX API server. (Default = 19101)
+		<value>19002</value>
+		<description>The port for the ASTERIX API server. (Default = 19002)
 		</description>
 	</property>
 
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
index 272140b..71b9129 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/LockManager.java
@@ -25,6 +25,7 @@
 import java.util.concurrent.locks.ReadWriteLock;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 
+import edu.uci.ics.asterix.common.config.AsterixTransactionProperties;
 import edu.uci.ics.asterix.common.exceptions.ACIDException;
 import edu.uci.ics.asterix.common.transactions.DatasetId;
 import edu.uci.ics.asterix.common.transactions.ILockManager;
@@ -108,6 +109,10 @@
             this.lockRequestTracker = new LockRequestTracker();
         }
     }
+     
+    public AsterixTransactionProperties getTransactionProperties() {
+        return this.txnSubsystem.getTransactionProperties();
+    }
 
     @Override
     public void lock(DatasetId datasetId, int entityHashValue, byte lockMode, ITransactionContext txnContext)
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/TimeOutDetector.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/TimeOutDetector.java
index 05052f0..7cbd193 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/TimeOutDetector.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/locking/TimeOutDetector.java
@@ -15,17 +15,19 @@
  */
 
 public class TimeOutDetector {
-    static final long TIME_OUT_THRESHOLD = 60000;
-    static final long SWEEP_PERIOD = 10000;//120000;
 
     LockManager lockMgr;
     Thread trigger;
     LinkedList<LockWaiter> victimList;
+    int timeoutThreshold;
+    int sweepThreshold;
 
     public TimeOutDetector(LockManager lockMgr) {
         this.victimList = new LinkedList<LockWaiter>();
         this.lockMgr = lockMgr;
         this.trigger = new Thread(new TimeoutTrigger(this));
+        this.timeoutThreshold = lockMgr.getTransactionProperties().getTimeoutWaitThreshold();
+        this.sweepThreshold = lockMgr.getTransactionProperties().getTimeoutSweepThreshold();
         trigger.setDaemon(true);
         AsterixThreadExecutor.INSTANCE.execute(trigger);
     }
@@ -39,7 +41,7 @@
     }
 
     public void checkAndSetVictim(LockWaiter waiterObj) {
-        if (System.currentTimeMillis() - waiterObj.getBeginWaitTime() >= TIME_OUT_THRESHOLD) {
+        if (System.currentTimeMillis() - waiterObj.getBeginWaitTime() >= timeoutThreshold) {
             waiterObj.setVictim(true);
             waiterObj.setWait(false);
             victimList.add(waiterObj);
@@ -68,7 +70,7 @@
     public void run() {
         while (true) {
             try {
-                Thread.sleep(TimeOutDetector.SWEEP_PERIOD);
+                Thread.sleep(owner.sweepThreshold);
                 owner.sweep(); // Trigger the timeout detector (the owner) to
                                // initiate sweep
             } catch (InterruptedException e) {
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
index 1e85c35..7947558 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/recovery/RecoveryManager.java
@@ -24,6 +24,7 @@
 import java.io.ObjectOutputStream;
 import java.io.OutputStream;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -90,6 +91,7 @@
     public static final boolean IS_DEBUG_MODE = false;//true
     private static final Logger LOGGER = Logger.getLogger(RecoveryManager.class.getName());
     private final TransactionSubsystem txnSubsystem;
+    private final int checkpointHistory;
 
     /**
      * A file at a known location that contains the LSN of the last log record
@@ -100,6 +102,7 @@
 
     public RecoveryManager(TransactionSubsystem TransactionProvider) throws ACIDException {
         this.txnSubsystem = TransactionProvider;
+        this.checkpointHistory = this.txnSubsystem.getTransactionProperties().getCheckpointHistory();
     }
 
     /**
@@ -516,8 +519,10 @@
 
         //#. delete the previous checkpoint files
         if (prevCheckpointFiles != null) {
-            for (File file : prevCheckpointFiles) {
-                file.delete();
+            // sort the filenames lexicographically to keep the latest checkpointHistory files.
+            Arrays.sort(prevCheckpointFiles);
+            for (int i = 0; i < prevCheckpointFiles.length - this.checkpointHistory; ++i) {
+                prevCheckpointFiles[i].delete();
             }
         }
 
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManagementConstants.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManagementConstants.java
index 5bc7647..25b9195 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManagementConstants.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/transaction/TransactionManagementConstants.java
@@ -26,7 +26,6 @@
     }
 
     public static class LogManagerConstants {
-        public static final String DEFAULT_LOG_DIR = "asterix_logs";
         public static final int TERMINAL_LSN = -1;
     }