when the brokers more than three. The problem of selectOneMessageQueue when send message

[542928492]

 When there are three or more borkers in one topic's routeinfo ---
TopicPublishInfo, for example broker-001,broker-002,broker-003,Some times the
selected messagequeue list may be broker-001 broker-002 broker-001,rather than
broker-001 broker-002 broker-003.

  When sending message to broker-001\broker-002 is timeout or other problem the send result will always be failed，and lose one chance to send broker-003. because it is
not set selected pos to sendWhichQueue's ThreadLocalIndex.

[542928492]

Reproduce code

import org.apache.rocketmq.client.common.ThreadLocalIndex;
import org.apache.rocketmq.common.message.MessageQueue;

import java.util.ArrayList;
import java.util.List;

public class MQTEST {

public static List<MessageQueue> messageQueueList = new ArrayList<>();
private static volatile ThreadLocalIndex sendWhichQueue = new ThreadLocalIndex();

public static void main(String[] args) {

    for (int i=0;i<8;i++){
        MessageQueue mq = new MessageQueue();
        mq.setBrokerName("b1");
        mq.setQueueId(i);
        mq.setTopic("TT");
        messageQueueList.add(mq);
    }

    for (int i=0;i<8;i++){
        MessageQueue mq = new MessageQueue();
        mq.setBrokerName("b2");
        mq.setQueueId(i);
        mq.setTopic("TT");
        messageQueueList.add(mq);
    }

    for (int i=0;i<8;i++){
        MessageQueue mq = new MessageQueue();
        mq.setBrokerName("b3");
        mq.setQueueId(i);
        mq.setTopic("TT");
        messageQueueList.add(mq);
    }

    MessageQueue mq = new MessageQueue();
    mq.setBrokerName("c1");
    mq.setQueueId(0);
    mq.setTopic("TT");
    messageQueueList.add(mq);

    MessageQueue mq2 = new MessageQueue();
    mq2.setBrokerName("c2");
    mq2.setQueueId(0);
    mq2.setTopic("TT");
    messageQueueList.add(mq2);

    MessageQueue mqtmp = null;
    for ( int times = 0; times < 3; times++) {
        String lastBrokerName = null == mqtmp ? null : mqtmp.getBrokerName();
        mqtmp= selectOneMessageQueue(lastBrokerName);
        System.out.println(mqtmp.getBrokerName());
    }

}

public static MessageQueue selectOneMessageQueue(final String lastBrokerName) {
    if (lastBrokerName == null) {
        return selectOneMessageQueue();
    } else {
        int index = sendWhichQueue.getAndIncrement();
        for (int i = 0; i < messageQueueList.size(); i++) {
            int pos = Math.abs(index++) % messageQueueList.size();
            if (pos < 0)
                pos = 0;
            MessageQueue mq = messageQueueList.get(pos);
            if (!mq.getBrokerName().equals(lastBrokerName)) {
                return mq;
            }
        }
        return selectOneMessageQueue();
    }
}
public static MessageQueue selectOneMessageQueue() {
    int index = sendWhichQueue.getAndIncrement();
    int pos = Math.abs(index) % messageQueueList.size();
    if (pos < 0)
        pos = 0;
    return messageQueueList.get(pos);
}

}

[542928492]

Repair plan

public static MessageQueue selectOneMessageQueue(final String lastBrokerName) {
if (lastBrokerName == null) {
return selectOneMessageQueue();
} else {

        for (int i = 0; i < messageQueueList.size(); i++) {
            //repair: move sendWhichQueue to here
            int index = sendWhichQueue.getAndIncrement();
            int pos = Math.abs(index) % messageQueueList.size();
            if (pos < 0)
                pos = 0;
            MessageQueue mq = messageQueueList.get(pos);
            if (!mq.getBrokerName().equals(lastBrokerName)) {
                return mq;
            }
        }
        return selectOneMessageQueue();
    }

[RongtongJin]

IMO, you are right. Could you submit a pull request to fix this issue?