We have been tumbling, for more than a month now, with an issue where a wcf msmq service hosted in IIS7.5 (WAS) will stop processing messages from the queue.
We have been unable to narrow it down more than "at some point" it will stop processing messages from the queue. Calling the svc through a http browser call will start the processing again.
After reading really many articles, blogs and forum posts about this issue we have ensured the following: Security settings, protocol bindings and msmq/service naming, but alas: the service will still stop processing messages (at some point).
Encouraged by this article http://www.daczkowski.net/2010/11/19/leveraging-msmq-in-asp-net-application-through-wcf-service/ we seem to have now finally (almost) eliminated the problem for windows server 2008 r2 sp1 64 bit, but it still seems to appear on Windows 7 32 bit.
Now to get to my question: Can anyone tell me if there actually exists a guarentee (documentation on this would be appreciated) that a msmq WAS hosted wcf service will actually restart (under all conditions) on a IIS7.5 NOT running the AppFabric extension?
I am aware that this question is very compounded, but I'm hard pressed for documentation on why we should extend our OTS package with AppFabric to resolve this restart problem.
Best regards,
Are you're net.msmq endpoints actually using addresses that IIS can bind to a queue name? It's possible to use non-IIS compatible names in the config and WAS won't really ever be able to wake your application up because WAS will only ever register to queues following a path name it can resolve. In that case you need something like AppFabric or a "startup" script to actually activate your services so that they will bind to the queues in their own.
Related
I'm working on my fourth or fifth implementation of a WCF service over MSQM with IIS/WAS activation. And I was never able to make it work properly. It's always the same story: my services are activated only if the IIS web site was interacted some other way (like servicing the service metadata page at /somewhere/myService.svc). Suddenly, if the only thing happening is sending messages into the queue, my services stop to process messages, and restart as soon as I visit the .svc page...
It's a so common pattern for me, that I also came to a common solution: scheduling a job (every few minutes) that runs a powershell script that access that page. Quite simple, but not very elegant. And, further more, unnecessary in theory.
This happened over different IIS versions (7.0 and 7.5), over various Win 2008 service packs and releases and with server in AD domains or workgroups. I think I've read every bits on the web about this, especially MSDN and microsofties blog, so binding configuration, MSMQ permissions, and all the other small details you can discover here and there are set up.
So the question: does anybody was successful with WAS over MSMQ?
I set up the Masstransit sample apps, and all was great. Local operation, msmq, looks good.
Now I am starting to put masstransit in my real app. In my real app, I have jobs coming from four servers, and processing happening on two worker systems.
It seems that masstransit always wants to push to:
msmq://localhost/...
But I thought I would set up a single, central, msmq server: msmq:///...
It appears (I may be missing something! Please correct me if I am off!) that when using msmq, that I need to set up msmq on multiple machines, and configure msmq to route from machine to machine.
Am I missing something?
Should I skip msmq and jump to rabbitmq right off, (which appears to solve for this)?
Is there some fundamental msmq knowledge (that is perhaps not in the masstransit docs) ?
thank you!
First off I always suggest people use RabbitMQ over MSMQ unless you MUST use DTC for some reason. And even then, I'd suggest you rethink using DTC.
But given you have some constraint you can't fight. You're welcomed to use a central MSMQ server but it doesn't provide a ton of value. Each server sending messages must have MSMQ installed locally because of how it works. Messages actually end up in an outgoing queue before they are sent over the other machine in question. If you have multi-machine MSMQ setups, in the past for me it's been like:
Core Machine runs MassTransit.RuntimeServices at /mt_subscriptions, and maybe one service at /service_1
Other processing machine runs a specific heavy load service at /service_2 and it's configuration references msmq://coremachine/mt_subscriptions for the subscription service.
Yet another processing machine with similar setup
So with those 3 machines, the only thing you don't have msmq://localhost/ is the reference to the subscription service in configuration.
I built a application with 5 wcf services and hosted them in IIS 7.5. I used the default configuration for the net.Tcp port (808*).
I am not used to host WCF services in IIS (I always hosted in Windows Services) and I found interesting that when I call the service (using tcp binding) I got two different process on the server.
One is SMSvcHost.exe (the one that is actually using the 808 port) and the other is w3wp.exe wich I think is handling a instance of the server I am calling.
I have a lot of questions so I will enumerate them:
Should I use IIS instead of Windows Service to host WCF Services (tcp binding) ?
The fact that I have two processes to answer my request means that I may have cpu impacts ?
Sometimes my services stop answering using the tcp binding. I got a timeout error on my clients but the mex is correctly answering if I go to the http://myServer/Service1.svc. I suspect that this problem is caused by fault connections but I am throwing exceptions correctly (using fault exceptions) and catching them correctly on my clients. Besides, I am also implementing a partial class for every service to dispose corretly (either using Close or Abort methods). Is there any way to figure out what's going on when the services stop answering ?
Shouldn't the w3wp.exe processes be closed after the client ends the request ? They remain on the Task Manager even when no one is using the services. I guess this is the reason of why my Entity Library logging locks the file after my request is completed.
Ideally it would be better hosted in Windows Activation Services (WAS) which is close to what you think of as IIS, but not quite. Here's a good introductory article on MSDN magazine:
http://msdn.microsoft.com/en-us/magazine/cc163357.aspx
What is the best way to combine a single instance WCF service that uses ActiveMQ and runs within IIS/AppFabric?
Our Services need to support both HTTP transports and ActiveMQ (listening and sending messages). We've elected not to use MSMQ, and will use Spring.Net.NMS. The fundamental issue I have now is that ActiveMQ needs to connect to the queue(s) at startup and remain connected, but WAS is getting in the way with it's message-activation feature. If the service is not activated until a message arrives (HTTP/MSMQ, etc) then there is no trigger to have the connection to AMQ occur.
I know I can disable the recycling behavior, and I know I can do self-hosting with a Windows Service. But I want to take advantage of the monitoring and other features in AppFabric. I've already been down the route with IServiceBehavior and will use that for other nice things. But that interface is not called until a (non-AMQ) message arrives. So it won't work for this. What I was hoping for was something along the line of how ServletContextListeners work in Java, where you get both the start up and shutdown events. But it seems no such thing exists in WAS... it is driven only by messages arriving.
I've scoured every inch of web info for 3 days and the only thing I came across was to use a static class construction (C#) trick as the trigger. That's a hack, but i can live with it. It still leaves the issue of cleanly shutting down, which I can figure out later.
Anyone have a solid solution to this?
The direct WCF support for ActiveMQ that Ladislav mentions is still being supported. There just hasn't been an official release for the module in a while. However, you can still get the latest version of it from the 1.5.x branch or trunk and compile it yourself.
1.5.x branch for use with Apache.NMS 1.5.0:
https://svn.apache.org/repos/asf/activemq/activemq-dotnet/Apache.NMS.WCF/branches/1.5.x/
Check out instructions:
http://activemq.apache.org/nms/source.html
There was direct WCF support for ActiveMQ but I guess it is not developed anymore. Your problem actually is the IIS / WAS (provides hosting for non-http protocols) hosting architecture. Services in WAS are always activated when message arrives - there is no global startup. The reason for this is that WAS hosting expects that there is separate process (windows service) running the listener all the time and this process has adapter which calls WAS and uses message level activation. I guess you don't have such process for ActiveMQ and because of that you will have trouble to use ActiveMQ endpoint hosted in WAS. Developing such listener can be challenging task (example for UDP).
Creating custom listener can be probably avoided by using IIS 7.5 / AppFabric auto start feature. There is also not very well documented way to run the code when the application starts.
I have a WCF service with netMsmqBinding. My client can send messages to my queue, and when the service is running it retrieves messages from the queue as expected. If the service is not running, messages received are queued until the service starts.
My problem is that the service does not start when a message hits the queue. The service is hosted in IIS, and so it is not instantiated until IIS receives a request. If I browse to the service then it processes the messages in the queue, but obviously this is not my desired method of processing the queue!
I expect that I need to change the service implementation, or change the IIS setup, but I do not know where or what to change.
UPDATE
Does anyone actually use MSMQ over WCF? I had this working for a short time - I enabled the binding on a different website on the same server, bizarrely - but now it has somehow stopped working again.
The only problem I am having is with the Activation of the service when there is a message in the queue. At present the queue only processes when the service is instantiated, e.g. when I browse the the .svc file. I have the net.msmq protocol enabled on the application, and I have the net.msmq binding enabled on the site... is there anything else I need to do?
You explicitly need to configure IIS for non HTTP activation. I don't know all the details of the top of my head but basically you need to use appcmd to configure and enable the net.msmq binding activation.
Check this blogpost or this screencast should give you all the details.
This might save somebody the hours it took me:
http://msdn.microsoft.com/en-us/library/ms731053.aspx
I believe that my problems using MSMQ binding over WCF were mainly around IIS.
I had no end of problems using Windows XP / Server 2003 with IIS 6.
Using Windows 7 or Server 2008 with IIS 7.5 everything works well.
An even better suggestion is to run MSMQ as a managed service / Windows Service or a stand-alone application rather than under IIS.