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Posted to commits@cassandra.apache.org by yu...@apache.org on 2012/12/19 19:43:57 UTC
[5/6] git commit: Fix M3P ownership calculation;
patch by yukim reviewed by Sylvain Lebresne for CASSANDRA-5076
Fix M3P ownership calculation; patch by yukim reviewed by Sylvain Lebresne for CASSANDRA-5076
Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo
Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/e7ae7c90
Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/e7ae7c90
Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/e7ae7c90
Branch: refs/heads/cassandra-1.2.0
Commit: e7ae7c9040135b6ecae5204efd7e41ad2e6ba4ee
Parents: 620a4b7
Author: Yuki Morishita <yu...@apache.org>
Authored: Wed Dec 19 12:43:23 2012 -0600
Committer: Yuki Morishita <yu...@apache.org>
Committed: Wed Dec 19 12:43:23 2012 -0600
----------------------------------------------------------------------
CHANGES.txt | 1 +
.../apache/cassandra/dht/Murmur3Partitioner.java | 14 +++--
.../apache/cassandra/dht/PartitionerTestCase.java | 40 ++++++++++++++-
3 files changed, 48 insertions(+), 7 deletions(-)
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http://git-wip-us.apache.org/repos/asf/cassandra/blob/e7ae7c90/CHANGES.txt
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diff --git a/CHANGES.txt b/CHANGES.txt
index 6edf7bb..7786b09 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -11,6 +11,7 @@ Merged from 1.1:
* Fix ALTER TABLE overriding compression options with defaults
(CASSANDRA-4996, 5066)
* fix specifying and altering crc_check_chance (CASSANDRA-5053)
+ * fix Murmur3Partitioner ownership% calculation (CASSANDRA-5076)
1.2-rc1
http://git-wip-us.apache.org/repos/asf/cassandra/blob/e7ae7c90/src/java/org/apache/cassandra/dht/Murmur3Partitioner.java
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diff --git a/src/java/org/apache/cassandra/dht/Murmur3Partitioner.java b/src/java/org/apache/cassandra/dht/Murmur3Partitioner.java
index 3e98e32..ad3579a 100644
--- a/src/java/org/apache/cassandra/dht/Murmur3Partitioner.java
+++ b/src/java/org/apache/cassandra/dht/Murmur3Partitioner.java
@@ -17,6 +17,7 @@
*/
package org.apache.cassandra.dht;
+import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.util.HashMap;
@@ -125,20 +126,21 @@ public class Murmur3Partitioner extends AbstractPartitioner<LongToken>
// n-case
else
{
- final float ri = MAXIMUM; // (used for addition later)
- Token start = (Token) i.next(); Long ti = ((LongToken)start).token; // The first token and its value
- Token t; Long tim1 = ti; // The last token and its value (after loop)
+ final BigInteger ri = BigInteger.valueOf(MAXIMUM).subtract(BigInteger.valueOf(MINIMUM.token + 1)); // (used for addition later)
+ final BigDecimal r = new BigDecimal(ri);
+ Token start = (Token) i.next();BigInteger ti = BigInteger.valueOf(((LongToken)start).token); // The first token and its value
+ Token t; BigInteger tim1 = ti; // The last token and its value (after loop)
while (i.hasNext())
{
- t = (Token) i.next(); ti = ((LongToken) t).token; // The next token and its value
- float age = ((ti - tim1 + ri) % ri) / ri; // %age = ((T(i) - T(i-1) + R) % R) / R
+ t = (Token) i.next(); ti = BigInteger.valueOf(((LongToken) t).token); // The next token and its value
+ float age = new BigDecimal(ti.subtract(tim1).add(ri).mod(ri)).divide(r, 6, BigDecimal.ROUND_HALF_EVEN).floatValue(); // %age = ((T(i) - T(i-1) + R) % R) / R
ownerships.put(t, age); // save (T(i) -> %age)
tim1 = ti; // -> advance loop
}
// The start token's range extends backward to the last token, which is why both were saved above.
- float x = ((((LongToken) start).token - ti + ri) % ri) / ri;
+ float x = new BigDecimal(BigInteger.valueOf(((LongToken)start).token).subtract(ti).add(ri).mod(ri)).divide(r, 6, BigDecimal.ROUND_HALF_EVEN).floatValue();
ownerships.put(start, x);
}
http://git-wip-us.apache.org/repos/asf/cassandra/blob/e7ae7c90/test/unit/org/apache/cassandra/dht/PartitionerTestCase.java
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diff --git a/test/unit/org/apache/cassandra/dht/PartitionerTestCase.java b/test/unit/org/apache/cassandra/dht/PartitionerTestCase.java
index 720ba3e..79b0d78 100644
--- a/test/unit/org/apache/cassandra/dht/PartitionerTestCase.java
+++ b/test/unit/org/apache/cassandra/dht/PartitionerTestCase.java
@@ -19,11 +19,14 @@
package org.apache.cassandra.dht;
import java.nio.ByteBuffer;
-import java.util.Random;
+import java.util.*;
import org.junit.Before;
import org.junit.Test;
+import static junit.framework.Assert.assertEquals;
+import static junit.framework.Assert.fail;
+
public abstract class PartitionerTestCase<T extends Token>
{
protected IPartitioner<T> partitioner;
@@ -115,4 +118,39 @@ public abstract class PartitionerTestCase<T extends Token>
Token.TokenFactory factory = partitioner.getTokenFactory();
assert tok("a").compareTo(factory.fromString(factory.toString(tok("a")))) == 0;
}
+
+ @Test
+ public void testDescribeOwnership()
+ {
+ try
+ {
+ testDescribeOwnershipWith(0);
+ fail();
+ }
+ catch (RuntimeException e)
+ {
+ // success
+ }
+ testDescribeOwnershipWith(1);
+ testDescribeOwnershipWith(2);
+ testDescribeOwnershipWith(256);
+ }
+
+ private void testDescribeOwnershipWith(int numTokens)
+ {
+ List<Token> tokens = new ArrayList<Token>();
+ while (tokens.size() < numTokens)
+ {
+ Token randomToken = partitioner.getRandomToken();
+ if (!tokens.contains(randomToken))
+ tokens.add(randomToken);
+ }
+ Collections.sort(tokens);
+ Map<Token, Float> owns = partitioner.describeOwnership(tokens);
+
+ float totalOwnership = 0;
+ for (float ownership : owns.values())
+ totalOwnership += ownership;
+ assertEquals(1.0, totalOwnership, 0.001);
+ }
}