weblogic中loadbalance的算法

BasicReplicaHandler.java
protected RemoteReference chooseReplica(RemoteReference remotereference, Method method, Object aobj[])
    {
        ReplicaList replicalist = replicaList;
        JVM INSTR monitorenter ;
        int i = replicaList.size();
        if(i == 0)
            return remotereference;
        current = (current + 1) % i;//选下一个
        replicaList.get(current);
        replicalist;
        JVM INSTR monitorexit ;
        return;
        Exception exception;
        exception;
        throw exception;
    }   

weblogic 中 loadbalance的三种典型算法：

随机

RandomReplicaHandler.java
protected RemoteReference chooseReplica(RemoteReference remotereference, Method method, Object aobj[]) {
        RandomReplicaHandler randomreplicahandler = this;
        JVM INSTR monitorenter ;
        ReplicaList replicalist;
        int i;
        replicalist = getReplicaList();
        i = replicalist.size();
        if(i == 0)
            return remotereference;
        int j;
        double d = Math.random() * (double)i + 0.5D;  // 随机数
        j = (int)Math.round(d) - 1;
        replicalist.get(j);
        randomreplicahandler;
        JVM INSTR monitorexit ;
        return;
        Exception exception;
        exception;
        throw exception;
    }

权重

WeightBasedReplicaHandler.java RichReplicaList.java
protected RemoteReference chooseReplica(RemoteReference remotereference, Method method, Object aobj[])
    {
        RichReplicaList richreplicalist = (RichReplicaList)getReplicaList();
        RemoteReference remotereference1 = remotereference;
        synchronized(richreplicalist)
        {
            if(infoArray == null || infoArray.length == 0)
                reinitializeWeightInfo(remotereference.getHostID());
            if(size != 0)
            {
                for(int i = lastIndex; i < size + lastIndex; i++)
                {
                    listIter = ++listIter % size;//用于判断是否重新计算当前调度的权值
                    if(listIter == 0)
                        loopCounter = ++loopCounter % maxIter;//当前调度的权值
                    int j = i % size;
                    if(infoArray[j].getNormalizedWeight() <= loopCounter)
                        continue;
                    remotereference1 = richreplicalist.findReplicaHostedBy(infoArray[j].getID());//大于当前调度的权值
                    if(remotereference1 == null)
                        continue;
                    lastIndex = ++j;
                    break;
                }
            }
        }
        return remotereference1;
    }
    
    
    maxIter:
    
    
     void resetAndNormalizeWeights()
    {
        int i = 0x7fffffff; //32位最大整数
        int j = 0x80000000; //32位最小整数
        boolean flag = true;
        synchronized(this)
        {
            serverInfoArray = ServerInfoManager.theOne().getServerInfos();
            for(int k = 0; k < serverInfoArray.length; k++)
            {
                int i1 = serverInfoArray[k].getLoadWeight();
                flag &= i1 % 10 == 0;
                if(i > i1)
                    i = i1;   //最小权重，尚未格式化
                if(i1 > j)
                    j = i1;  //最大权重，尚未格式化
            }
            int l = 0;
            if(serverInfoArray.length > 0)
                while(serverInfoArray[l].getLoadWeight() % i == 0 && ++l < serverInfoArray.length) ;
            if(l > serverInfoArray.length)
            {
                normalizeWeights(i, serverInfoArray);
                loopIter = j / i;
            } else
            if(flag)
            {
                normalizeWeights(10, serverInfoArray);
                loopIter = j / 10;
            } else
            {
                normalizeWeights(5, serverInfoArray);
                loopIter = j / 5;
            }
        }
    }

顺序