如果服务关闭一段时间,如何在c#中重新连接到MSMQ

本文关键字:重新连接 MSMQ 服务 一段时间 如果 | 更新日期: 2023-09-27 18:16:53

是否有可能在服务关闭后重新连接到MSMQ,而不重新启动我的应用程序?如果是,那是怎么回事?

我的代码是:
void tmrDelay_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {
        tmrDelay.Stop();
        while (isConnected)
        {
            try
            {
                if (ImportFromMSMQ.HasMessages())
                {
                    MSMQ_ServiceLog.WriteEntry(string.Format("Transfering data from MSMQ to ActiveMQ started at {0}", DateTime.Now.ToString()));
                    while (ImportFromMSMQ.HasMessages())
                    {
                        ImportFromMSMQ.Run();
                        MSMQ_ServiceLog.WriteEntry(string.Format("Transfering data from MSMQ to ActiveMQ completed at {0}", DateTime.Now.ToString()));
                    }
                }
                else
                {
                    MSMQ_ServiceLog.WriteEntry(string.Format("MSMQ is empty {0}", DateTime.Now.ToString()));
                }
            }
            catch (Exception ex)
            {
                logger.Error(string.Format(" Error in data transfer MSMQ to ActiveMQ {0}", ex.Message));
                MSMQ_ServiceLog.WriteEntry(string.Format(" Error in data transfer MSMQ to ActiveMQ {0}", ex.Message), EventLogEntryType.Error, -1);
            }
        }
        tmrDelay.Start();
    } 

while循环是我添加的,但还没有测试,因为怀疑是无限循环。如果关闭了MSMQ服务,我们就会在catch子句中结束,当MSMQ再次启动时,我们需要重新启动整个应用程序。但是,我如何重试连接到MSMQ,并在等待它再次启动时继续这样做?

public class ImportFromMSMQ
    {
        private static readonly ILog logger = LogManager.GetLogger(typeof(ImportFromMSMQ));
        //Max records per records
        private static int _maxMessagesPerTransaction = ConstantHelper.MaxMessagesPerTransaction;
        private static bool _isNotCompleted = true;
        private static  int counter = 0;
        private static MessageQueue mq;
        private static long _maxMessageBodySizeLimitInBytes =  ConstantHelper.MaxMessageBodySizeLimitInBytes;
    // Start import 
    public static void Run()
    {
        Start();
    }
    public static bool HasMessages()
    {
        var _mqName = ConstantHelper.SourceQueue;
        mq = new System.Messaging.MessageQueue(_mqName);
        long _totalmsg = MessagesCounter.GetMessageCount(mq);
        if (_totalmsg > 0)
        {
            logger.Info(string.Format(" {0} messages found in the {1} Queue ", _totalmsg.ToString(), _mqName));
        }
        else
        {
            logger.Info(string.Format(" There are no messages in the {1} Queue ", _totalmsg.ToString(), _mqName));
        }
        return _totalmsg > 0; 
    }

    private static void Start()
    { 
        logger.Info(string.Format("Data transfer starting at {0}", DateTime.Now.ToString()));
        long _currentMessageBodySizeLimitInBytes = 0;
        ArrayList messageList = new ArrayList();
        System.Messaging.Message mes;
        System.IO.Stream bodyStream = null;
        // Create a transaction.
        MessageQueueTransaction trans = new MessageQueueTransaction();
        List<ConventionalData> objectList = new List<ConventionalData>();
        IMessageContainer _container = new MessageContainer();
        // Begin the transaction.
        trans.Begin();
        try
        {
            while (_isNotCompleted && counter < _maxMessagesPerTransaction)
            {
                try
                {
                    counter++;
                    mes = mq.Receive(new TimeSpan(0, 0, 3), trans);
                    if (mes != null)
                    {
                        bodyStream = mes.BodyStream;
                        _currentMessageBodySizeLimitInBytes = _currentMessageBodySizeLimitInBytes + bodyStream.Length;
                    }
                   VisionAir.Messaging.ConventionalData data = ProtoBuf.Serializer.Deserialize<ConventionalData>(mes.BodyStream);
                   objectList.Add(data);
                   _isNotCompleted = _currentMessageBodySizeLimitInBytes <= _maxMessageBodySizeLimitInBytes;
                }
                catch
                {
                    _isNotCompleted = false;
                }
            }
            if (objectList.Count != 0) 
            {
                logger.Info(string.Format("Starting transfer of {0} messages", objectList.Count));
                _container.MQMessages = objectList;
                 ExportToActiveMQ _export = new ExportToActiveMQ(_container, (ExportOption) Enum.Parse(typeof(ExportOption),ConstantHelper.ExportFormat));
                _export.Export();
            }
            logger.Info(string.Format("Transfer of {0} messages is completed at {1}",objectList.Count, DateTime.Now.ToString()));
            // Commit transaction            
            trans.Commit();
            counter = 0; //ResetF
            _isNotCompleted = true; //Reset
        }
        catch (Exception ex)
        {
            logger.Error(ex);
            // Roll back the transaction.
            trans.Abort();
            counter = 0;
        }
    }
}

我看过这个问题服务没有收到消息后消息队列服务重启,但似乎不完全理解它,所以如果有人能详细说明它,这将是很好的。

我必须递归地调用我的tmrDelay_Elapsed()方法,我的catch子句或其他什么?

如果服务关闭一段时间,如何在c#中重新连接到MSMQ

我找到了解决方案,当我第一次意识到我们第一次访问队列是在HasMessages()方法中时,这很简单,所以我将其更改为以下内容:

public static bool HasMessages()
        {
            var _mqName = ConstantHelper.SourceQueue;
            long _totalmsg = 0;
            int countAttempts = 0;
        queueExists = false;
        while (!queueExists)
        {
            if (MessageQueue.Exists(_mqName))
            {
                queueExists = true;
                mq = new System.Messaging.MessageQueue(_mqName);
                _totalmsg = MessagesCounter.GetMessageCount(mq);
                if (_totalmsg > 0)
                {
                    logger.Info(string.Format(" {0} messages found in the {1} Queue ", _totalmsg.ToString(), _mqName));
                }
                else
                {
                    logger.Info(string.Format(" There are no messages in the {1} Queue ", _totalmsg.ToString(), _mqName));
                }
            } 
            else
            {
                logger.Info(string.Format("No Queue named {0} found, trying again.", _mqName));
                countAttempts++;
                if(countAttempts % 10 == 0)
                {
                    logger.Info(string.Format("Still no queue found, have you checked Services that Message Queuing(Micrsoft Message Queue aka. MSMQ) is up and running"));
                } 
                Thread.Sleep(5000);
            }
        }
        return _totalmsg > 0; 
    }

我检查是否MessageQueue.Exists并继续尝试,如果它不存在,直到我找到队列。当我找到它时,我将queueExists设置为true,以中断while循环,继续处理接收到的数据(如果接收到任何数据)。我在一些帖子中读到,使用Thread.Sleep(n)是不好的,但现在我要用这个解决方案。