org.apache.cassandra.repair.asymmetric

Class ReduceHelper

java.lang.Object

org.apache.cassandra.repair.asymmetric.ReduceHelper

public class ReduceHelper
extends java.lang.Object

Basic idea is that we track incoming ranges instead of blindly just exchanging the ranges that mismatch between two nodes Say node X has tracked that it will stream range r1 from node Y. Now we see find a diffing range r1 between node X and Z. When adding r1 from Z as an incoming to X we check if Y and Z are equal on range r (ie, there is no difference between them). If they are equal X can stream from Y or Z and the end result will be the same. The ranges wont match perfectly since we don't iterate over leaves so we always split based on the smallest range (either the new difference or the existing one)

Constructor Summary

Constructors

Constructor and Description
ReduceHelper()

Method Summary

Modifier and Type	Method and Description
static com.google.common.collect.ImmutableMap<InetAddressAndPort,HostDifferences>	reduce(DifferenceHolder differences, PreferedNodeFilter filter) Reduces the differences provided by the merkle trees to a minimum set of differences

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ReduceHelper

public ReduceHelper()

Method Detail

reduce

public static com.google.common.collect.ImmutableMap<InetAddressAndPort,HostDifferences> reduce(DifferenceHolder differences,
                                                                                                PreferedNodeFilter filter)

Reduces the differences provided by the merkle trees to a minimum set of differences