Is there a way to modify a Message in the MessageQueue without removing it?
IDEA here is that an App (app1) sends a message to MSMQ, which APP (app2) listens to MSMQ
and retrieves the message. app2 has to update the data (Message.Body) which will is used
for future reference. Finally app3 will remove it after message is processed.
I am afraid the answer is NO. Messaging provider are not built for this scenario. The only way to "update" a message is to retrieve that message, modify it and put it back again. But note that updated message is another message altogether, not same as the one put by first application.
Related
Right now I am writing a chat application I am having a list of messages initially when the message was sent it had status property sending after getting network confirmation it should update and change to sent after getting confirmation whether the message is received by the recipient it should change to delivered and then to seen what is the ideal approach to do this I thought a way to copy the properties of that message and after changing status insert that particular message at that index since my message class is immutable.
Thank you.
are you using a streambuilder? I think using a streambuilder should get this done, you can give it a try if you are not using it already.
I have java server application. And I need to monitor a lot of gmail accounts to be able to send push notifications to mobile devices about new Inbox messages.
I need to know sender email and message subject to send push notification.
And I tried Gmail push notifications system (webhooks option)
If I understood everything correctly in order to get needed info for each new message for each user there is a following scenario:
Google sends me email and history id via https request.
I call history API and get new message ids for user
I request message info by message id
That means that I need 2 additional requests for each new message of each user. And it looks quite hard if server needs to handle several new messages each second. And I still don't see other way.
Is there any way to make it shorter? (e.g. to make google send me not only history id but needed new message details or at least make one additional request, but not two)
Thanks!
We tried using Push notifications but the volume of requests generated has meant that we poll on a timed basis instead. It is worth noting that you will get Push notifications for any change to the message such as a label change, a read status change etc. As you say there are many requests.
If you need the notifications real-time I don't see how you can avoid the process that you outline.
If you don't need it real-time then you can poll or at the least check for Push notifications per account on a timed basis and if some have been received retrieve any new messages in a batch rather than a single request.
I was facing the same problem. History API was not giving recent messageId. I solved this problem by hitting THREAD API where i set Q = last 5 min timestamp.
Webhook push notification is helping to notify a new mail has come. After i get all messages last 10 min with THREAD API.
I am currently looking to buildout a messaging service where users can send and receive messages privately between each other. I may have a need for multi-user chat, but for the most part, I only want single recipients to be able to read messages sent to them.
With looking at RabbitMQ, does it make sense to use one exchange, and create a queue for each user when they login and destroy each queue on logout? Are there major performance issues with creating a queue for each user or are there better alternatives?
I am building a REST API and plan on having users send messages to others through an endpoint (/send) and subscribe to their own message streams via websockets or something similar. I will probably store messages in MongoDB as well, so users can access all of their previous messages. Any suggestions on structure are appreciated.
I think your approach is correct. You event don't need an exchange if you will use the default exchange (AMQP Default). And during login create a new queue and keep queue name same as user name. (Just need to make sure user names are unique) And if you publish message to the default exchange with username (ie: queue name) as routing key, RbbitMQ will route that message to that queue only. And on logout if you delete the queue then user is going to miss the messages when he is not online. If it is OK then create queue after login and use the configuration exclusive which says queue gets deleted when there is no consumer. But if you want to keep offline messages then you need to create queue permanently during user signup.
I'm trying to implement chat for my webapp with following features:
When user logs in he should see a number of unread messages (which is both offline messages and "unseen", I will explain "unseen" in next step).
When user is anywhere in the app but on chat window he should be notified that he has a new message. Message should be marked "unseen" and must be added to the count of unread messages.
The first point is quite easily achieved using XEP-0013: Flexible Offline Message Retrieval. So I can retrieve offline messages and when I'm sure user has seen them - I remove them from unread list. But the problem is: how do I achieve same thing for "unseen" messages?
In short what I need is: any message should be marked as offline, unless user sees it and it's removed from the list by explicit request.
Can I achieve that with XMPP and how do I do that?
Thanks in advance.
What you are trying to do is to basically store a counter of unseen stuff in your account. I think you do not need flexible offline retrieval as when you connect the messages would simply become unseen. You thus only have to deal with one case: Unseen.
I will reply from the perspective of ejabberd, that I know better as one of the developer: I would use private storage to store your current state of unseen count and conversation.
I need to get the Id of a msmq message inside of my handler so I can write that Id to a log.
When a message is sent to the error queue an email is sent informing us of a failed message. Once the error that caused the message is resolved we need to use the 'ReturnToSourceQueue' NServiceBus tool to try that message again. Without logging that Id, it would be difficult to track down which message is which when looking through the message queues.
Every where I've looked suggests that Bus.CurrentMessageContext.Id will give me the same Id that's in the Message ID column when looking at the queues in ComputerManagement->Services and Applications->Message Queuing->[Some Queue]->Queue messages. However, those ids don't seem to be the same.
What am I missing?
The reason that the message ID that you see in MMC plugin or Queue Explorer is different is that when the message is "moved" to the error queue, what actually happens is that a new MSMQ message is created with the same body and headers and that is sent to the error queue.
Also, when the processing a message fails, NServiceBus already logs this for you and includes the ID of the message, so that's already done for you.
If you take the ID that was logged and pass that to the ReturnToSourceQueue tool, everything will just work.
The last piece of the puzzle for you is sending an email when a message fails. Now, I'm not sure that that is the wisest idea as you may end up spamming your ops team when a database goes offline or a 3rd party webservice becomes unresponsive. Still, if that's what you want to do, then I'd suggest using an email appender for when errors are logged.
Finally, let me say that we're in the process of building this kind of notification functionality into the Particular Service Platform around NServiceBus. We've got a UI showing errors and allowing messages to be reprocessed coming as a beta in November '13 and the notification functionality will probably be ready towards the end of the year.
It's really a question of whether you want to wait or to build this yourself.
Just create an instance of your bus in your handler:
public IBus Bus { get; set; }
Then use that to get the message id:
this.Bus.CurrentMessageContext.Id
The Bus instance will be injected when the handler is called.
EDIT
Now that I have actually read the question...
The CurrentMessageContext.Id returns what's in the message header under the CorrId field. This can be seen in the Label column in Server Management.
The Message ID displayed in the MessagId column is the message ID as it existed on the sending computer. I am not sure how to access this value from CurrentMessageContext but you should not need to do this to find a local message.