How to reconsume exchange after rabbitmq server down? - rabbitmq

Hi i'm wondering is there any way to try to keep continue consuming an exchange after rabbitMQ server down over .net?

Related

NserviceBus - What happens to a message if the server is offline

I went thought NServiceBus documentation including the durable messaging one. What I understand is that when the server is offline the messages continue to go into the server's input queue which get picked up when server comes back online.
But what if the server is completely down and the input queue is not accessible?
I'm using Bus.Send from the client.
It depends on what transport you're using.
In the case of a brokered message queue, like Azure Service Bus, as long as that service is available, the fact the machine that will eventually retrieve the messages is offline is irrelevant, as that machine is simply asking the external queuing service for messages. The same goes for a transport like SQL Server.
In the case of a transport like MSMQ, which is a store a forward style queue, the messages will remain in a local outgoing queue until the remote machine becomes available.
Can you double check that you are looking in the correct spot? If you aren't getting an error out of NServiceBus when you Send, then MSMQ is installed. If it can't be reached or the service is stopped you should get errors.
The Outbound queues are in a different place as illustrated here:
http://blogs.msdn.com/cfs-filesystemfile.ashx/__key/communityserver-components-postattachments/00-09-06-31-16/outgoingempty.JPG
As RMD indicated, this is an advantage of the store and forward MSMQ transport.. the local outbound queue should just stack these up until the remote server is available.
Thx.
Joe

RabbitMQ mirroring queues and exchanges

Is it possible to use federations or shovels to mirror the creation of exchanges and queues on one server to another ?
All the examples I've seen of using shovels and federations use exchanges and queues that already exist on the servers. What I want to do is create an exchange on server A and have a federation or shovel re-create it on Server B then start to send messages to it.
If this cannot be done with a federation or shovel is there anyway of achieving this without using clustering, the connection between the two servers is not consistent so clustering isn't possible.
I'm running RabbitMQ on windows.
You can use the federation plug-in.
It supports the exchange exchange and the queue federation, in order to mirror the queues and exchanges you can configure a policies ( using the management console or command line),for example with this parameters:
Name: my_policy
Pattern: ^mirr\. <---- mirror exchanges and queues with prefix “mirr.”
Definition: federation-upstream-set:all
you can apply the configuration for exchanges and queues, as:
The pattern policy supports regular expression
In this way each new or old exchange or queue that starts with the prefix “mirr.” will be mirrored to the other broker.
I think this could solve your problem.
Unfortunately in this way it is not possible to do this, because the connection is a point-to-point connection. You have to link a exchange with a remote exchange and in your topology this cant be created automatically.
I had also this problem in the past. And how i resolved the problem was over a business logic side. If there was a need for a new Exchange/Queue "on the fly", my data input gateway recognized this and created on the local and on the remote exchange the new exchange and queues with the connection, before the message was sent to RabbitMQ.

linking multiple queues to same service in SQL service broker

Hi Everyone,
I have just started working with SQL service broker. I was wondering if we can link two service broker queues to same service such that when a message is sent using that service, it will be delivered to both queues i.e both the queues will contain same copy of a message. Is there any way like this or there is some other way to do this?
Thanks in advance
Pankaj
No, in SQL 2008, service broker only supports DIALOG conversations, not MONOLOG, meaning there can be only one endpoint.

nservicebus can handle db client to msmq backend?

I wonder is nservicebus pub/sub or other type of app can handle db client to msmq server.
For example I have a desktop client app. using db queue and i want to send message to server using msmq message queue.
Thanks
Take a look at this article about interop with SQL Server: http://andreasohlund.net/2010/09/03/event-based-interop-with-service-broker/. There exists an Oracle AQS transport as well if you are using Oracle.
The article describes how to setup a bridge between the DB queue and MSMQ.

Windows Azure Queues, WCF, MSMQ integration

I have a scenario where I need a desktop console app to communicate with a Windows Azure Queue... the most important thing is that the message is received by the server eventually. Also, the desktop app may be disconnected from the Internet sometimes. In the traditional WCF+MSMQ approach you'd be able to send a message which would be cached in MSMQ until MSMQ could reach the Server's MSMQ and send the message. What's the equivalent when Windows Azure is the server-side?
Is it possible for the same approach to be used, where MSMQ just communicates with a Windows Azure Queue rather than an MSMQ on a Windows Server?
Maybe Windows Azure Queue is the wrong approach? I have heard about something called message buffer, but don't know what this is (yet!).
thanks for your help
Kris
You could write an MSMQ listener service that finishes moving the message to the Azure queue when the connection to the internet has been reestablished. I don't think this would be too difficult.
Update
Perhaps my answer wasnt clear. Based on the question the client is occasionally connected to the internet so you need a way to park the message until the intertubes get untangled. Using Windows the easiest way to do this is to put the message in an MSMQ local queue. YOu then have a service monitoring that queue. If there is a message and it can get to the service hosted in the cloud it sends the message. Once the message has been sent it can be deleted from the queue.
In order to queue a message to Azure Queue Storage you have to be connected to the Internet. If you want to handle disconnected scenarios, that is totally up to you. I would keep the solution very simple and use a local storage such as SQL Server Compact and then send the messages as soon as there's connectivity, maybe with the aid of a Windows Service (so that you don't need to run the desktop app).
You can do this with the Azure AppFabric Service Bus Message Buffers - there is no need to use a Queue. Check out the related sample downloads on the following site: http://www.idesign.net/idesign/DesktopDefault.aspx?tabindex=5&tabid=11 - they should answer your questions much better than I can.
Regards