make out-of-the-box config 1GB-friendly. patch by jbellis; reviewed by Eric Evans for CASSANDRA-118

git-svn-id: https://svn.apache.org/repos/asf/incubator/cassandra/trunk@770811 13f79535-47bb-0310-9956-ffa450edef68

bin/cassandra.in.sh

@@ -22,7 +22,7 @@ JVM_OPTS=" \
         -Xdebug \
         -Xrunjdwp:transport=dt_socket,server=y,address=8888,suspend=n \
         -Xms128M \
-        -Xmx2G \
+        -Xmx1G \
         -XX:SurvivorRatio=8 \
         -XX:TargetSurvivorRatio=90 \
         -XX:+AggressiveOpts \

conf/storage-conf.xml

@@ -79,13 +79,14 @@
       is based solely on the amount of data stored, not actual heap memory
       usage (there is some overhead in indexing the columns).
     -->
-    <MemtableSizeInMB>64</MemtableSizeInMB>
+    <MemtableSizeInMB>32</MemtableSizeInMB>
 
     <!--
       The maximum number of columns in millions to store in memory
-      before flushing to disk.  Use with MemtableSizeInMB to tune memory usage.
+      before flushing to disk.  This is also a per-memtable setting.
+      Use with MemtableSizeInMB to tune memory usage.
     -->
-    <MemtableObjectCountInMillions>1</MemtableObjectCountInMillions>
+    <MemtableObjectCountInMillions>0.1</MemtableObjectCountInMillions>
 
     <!-- Time to wait before garbage-collection deletion markers.
          Set this to a large enough value that you are confident

src/java/org/apache/cassandra/config/DatabaseDescriptor.java

@@ -97,7 +97,7 @@ public class DatabaseDescriptor
     /* Size of the memtable in memory before it is dumped */
     private static int memtableSize_ = 128;
     /* Number of objects in millions in the memtable before it is dumped */
-    private static int memtableObjectCount_ = 1;
+    private static double memtableObjectCount_ = 1;
     /* 
      * This parameter enables or disables consistency checks. 
      * If set to false the read repairs are disable for very
@@ -214,7 +214,11 @@ public class DatabaseDescriptor
             /* Number of objects in millions in the memtable before it is dumped */
             String memtableObjectCount = xmlUtils.getNodeValue("/Storage/MemtableObjectCountInMillions");
             if ( memtableObjectCount != null )
-                memtableObjectCount_ = Integer.parseInt(memtableObjectCount);
+                memtableObjectCount_ = Double.parseDouble(memtableObjectCount);
+            if (memtableObjectCount_ <= 0)
+            {
+                throw new ConfigurationException("Memtable object count must be a positive double");
+            }
 
             /* This parameter enables or disables consistency checks.
              * If set to false the read repairs are disable for very
@@ -516,7 +520,7 @@ public class DatabaseDescriptor
       return memtableSize_;
     }
 
-    public static int getMemtableObjectCount()
+    public static double getMemtableObjectCount()
     {
       return memtableObjectCount_;
     }

src/java/org/apache/cassandra/db/Memtable.java

@@ -73,7 +73,7 @@ public class Memtable implements Comparable<Memtable>
     private MemtableThreadPoolExecutor executor_;
 
     private int threshold_ = DatabaseDescriptor.getMemtableSize()*1024*1024;
-    private int thresholdCount_ = DatabaseDescriptor.getMemtableObjectCount()*1024*1024;
+    private int thresholdCount_ = (int)(DatabaseDescriptor.getMemtableObjectCount()*1024*1024);
     private AtomicInteger currentSize_ = new AtomicInteger(0);
     private AtomicInteger currentObjectCount_ = new AtomicInteger(0);
 

test/cassandra.in.sh

@@ -23,7 +23,7 @@ JVM_OPTS=" \
         -Xdebug \
         -Xrunjdwp:transport=dt_socket,server=y,address=8888,suspend=n \
         -Xms128M \
-        -Xmx2G \
+        -Xmx1G \
         -XX:SurvivorRatio=8 \
         -XX:TargetSurvivorRatio=90 \
         -XX:+AggressiveOpts \