package org.infinispan.distribution.ch;
import org.infinispan.commons.hash.MurmurHash3;
import org.infinispan.distribution.ch.impl.DefaultConsistentHash;
import org.infinispan.distribution.ch.impl.OwnershipStatistics;
import org.infinispan.distribution.ch.impl.SyncConsistentHashFactory;
import org.infinispan.distribution.ch.impl.TopologyAwareSyncConsistentHashFactory;
import org.infinispan.remoting.transport.Address;
import org.infinispan.remoting.transport.jgroups.JGroupsTopologyAwareAddress;
import org.infinispan.test.AbstractInfinispanTest;
import org.jgroups.util.ExtendedUUID;
import org.jgroups.util.TopologyUUID;
import org.jgroups.util.UUID;
import org.testng.annotations.Test;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import static java.lang.Math.sqrt;
import static org.testng.AssertJUnit.assertEquals;
/**
* Tests the uniformity of the SyncConsistentHashFactory algorithm, which is very similar to the 5.1
* default consistent hash algorithm virtual nodes.
*
* <p>This test assumes that key hashes are random and follow a uniform distribution so a key has the same chance
* to land on each one of the 2^31 positions on the hash wheel.
*
* <p>The output should stay pretty much the same between runs, so I added and example output here: vnodes_key_dist.txt.
*
* <p>Notes about the test output:
* <ul>
* <li>{@code P(p)} is the probability of proposition {@code p} being true
* <li>In the "Primary" rows {@code mean == total_keys / num_nodes} (each key has only one primary owner),
* but in the "Any owner" rows {@code mean == total_keys / num_nodes * num_owners} (each key is stored on
* {@code num_owner} nodes).
* </ul>
* @author Dan Berindei
* @since 5.2
*/
@Test(testName = "distribution.ch.TopologyAwareSyncConsistentHashFactoryKeyDistributionTest", groups = "profiling")
public class TopologyAwareSyncConsistentHashFactoryKeyDistributionTest extends SyncConsistentHashFactoryKeyDistributionTest {
@Override
protected DefaultConsistentHash createConsistentHash(int numSegments, int numOwners, List<Address> members) {
MurmurHash3 hash = new MurmurHash3();
ConsistentHashFactory<DefaultConsistentHash> chf = new TopologyAwareSyncConsistentHashFactory();
DefaultConsistentHash ch = chf.create(hash, numOwners, numSegments, members, null);
return ch;
}
@Override
protected List<Address> createAddresses(int numNodes) {
ArrayList<Address> addresses = new ArrayList<Address>(numNodes);
for (int i = 0; i < numNodes; i++) {
addresses.add(new IndexedTopologyAwareJGroupsAddress(TopologyUUID.randomUUID("s" + (i%2), null, "m" + i), i));
}
return addresses;
}
}
/**
* We extend JGroupsAddress to make mapping an address to a node easier.
*/
class IndexedTopologyAwareJGroupsAddress extends JGroupsTopologyAwareAddress {
final int nodeIndex;
public IndexedTopologyAwareJGroupsAddress(ExtendedUUID address, int nodeIndex) {
super(address);
this.nodeIndex = nodeIndex;
}
}