feat[load-balancer]: fast load balancer

net/src/main/java/com/zfoo/net/consumer/balancer/ConsistentHashConsumerLoadBalancer.java

@@ -15,6 +15,7 @@ package com.zfoo.net.consumer.balancer;
 
 import com.zfoo.net.NetContext;
 import com.zfoo.net.session.Session;
+import com.zfoo.net.util.ReadOnlyTreeMapIntLong;
 import com.zfoo.protocol.IPacket;
 import com.zfoo.protocol.ProtocolManager;
 import com.zfoo.protocol.collection.CollectionUtils;
@@ -24,6 +25,7 @@ import com.zfoo.protocol.registration.ProtocolModule;
 import com.zfoo.util.math.ConsistentHash;
 import org.springframework.lang.Nullable;
 
+import java.util.TreeMap;
 import java.util.concurrent.atomic.AtomicReferenceArray;
 import java.util.stream.Collectors;
 
@@ -40,7 +42,7 @@ public class ConsistentHashConsumerLoadBalancer extends AbstractConsumerLoadBala
     public static final ConsistentHashConsumerLoadBalancer INSTANCE = new ConsistentHashConsumerLoadBalancer();
 
     private volatile int lastClientSessionChangeId = 0;
-    private static final AtomicReferenceArray<ConsistentHash<String, Long>> consistentHashMap = new AtomicReferenceArray<>(ProtocolManager.MAX_MODULE_NUM);
+    private static final AtomicReferenceArray<ReadOnlyTreeMapIntLong> consistentHashMap = new AtomicReferenceArray<>(ProtocolManager.MAX_MODULE_NUM);
     private static final int VIRTUAL_NODE_NUMS = 200;
 
     private ConsistentHashConsumerLoadBalancer() {
@@ -78,28 +80,46 @@ public class ConsistentHashConsumerLoadBalancer extends AbstractConsumerLoadBala
         }
 
         var module = ProtocolManager.moduleByProtocolId(packet.protocolId());
-        var consistentHash = consistentHashMap.get(module.getId());
+        var treeMap = consistentHashMap.get(module.getId());
-        if (consistentHash == null) {
+        if (treeMap == null) {
-            consistentHash = updateModuleToConsistentHash(module);
+            treeMap = updateModuleToConsistentHash(module);
         }
-        if (consistentHash == null) {
+        if (treeMap == null) {
             throw new RunException("ConsistentHashLoadBalancer [protocolId:{}][argument:{}], no service provides the [module:{}]", packet.protocolId(), argument, module);
         }
-        var sid = consistentHash.getRealNode(argument).getValue();
+        var index = treeMap.indexOfCeilingKey(argument.hashCode());
-        return NetContext.getSessionManager().getClientSession(sid);
+        if (index < 0) {
+            throw new RunException("no service provides the [module:{}]", packet.protocolId(), argument, module);
+        }
+        var sid = treeMap.getByIndex(index);
+        var session = NetContext.getSessionManager().getClientSession(sid);
+        if (session == null) {
+            throw new RunException("unknown no service provides the [module:{}]", packet.protocolId(), argument, module);
+        }
+        return session;
     }
 
 
     @Nullable
-    private ConsistentHash<String, Long> updateModuleToConsistentHash(ProtocolModule module) {
+    private ReadOnlyTreeMapIntLong updateModuleToConsistentHash(ProtocolModule module) {
         var sessionStringList = getSessionsByModule(module).stream()
                 .map(session -> new Pair<>(session.getConsumerAttribute().toString(), session.getSid()))
                 .sorted((a, b) -> a.getKey().compareTo(b.getKey()))
                 .collect(Collectors.toList());
 
-        var consistentHash = CollectionUtils.isNotEmpty(sessionStringList) ? new ConsistentHash<>(sessionStringList, VIRTUAL_NODE_NUMS) : null;
+        var consistentHash = new ConsistentHash<>(sessionStringList, VIRTUAL_NODE_NUMS);
-        consistentHashMap.set(module.getId(), consistentHash);
+        var virtualNodeTreeMap = consistentHash.getVirtualNodeTreeMap();
-        return consistentHash;
+        if (CollectionUtils.isEmpty(virtualNodeTreeMap)) {
+            consistentHashMap.set(module.getId(), null);
+            return null;
+        }
+        var virtualTreeMap = new TreeMap<Integer, Long>();
+        for (var entry : virtualNodeTreeMap.entrySet()) {
+            virtualTreeMap.put(entry.getKey(), entry.getValue().getValue());
+        }
+        var treeMap = new ReadOnlyTreeMapIntLong(virtualTreeMap);
+        consistentHashMap.set(module.getId(), treeMap);
+        return treeMap;
     }
 
 }

util/src/main/java/com/zfoo/util/math/ConsistentHash.java

@@ -15,7 +15,10 @@ package com.zfoo.util.math;
 
 import com.zfoo.protocol.model.Pair;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.TreeMap;
 
 /**
  * 带虚拟节点的一致性Hash算法，参考：http://www.zsythink.net/archives/1182
@@ -69,5 +72,7 @@ public class ConsistentHash<K, V> {
         return entry.getValue();
     }
 
-
+    public TreeMap<Integer, Pair<K, V>> getVirtualNodeTreeMap() {
+        return virtualNodeTreeMap;
+    }
 }