We have a rather large document routing framework that's currently implemented in SharePoint (with a large set of cumbersome SP workflows), and it's running into the edge of what SP can do easily. It's slated for a rewrite into .NET
I've spent the past week or so reading and watching WF4 discussions and demonstrations to get an idea of WF4, because I think it's the right solution. I'm having difficulty envisioning how the system will be configured, though, so I need guidance on a few points from people with experience:
Let's say I have an approval that has to be made on a document. When the wf starts, it'll decide who should approve, and send that person an email notification. Inside the notification, the user would have an option to load an ASP.NET page to approve or reject. The workflow would then have to be resumed from the send email step. If I'm planning on running this as a WCF WF Service, how do I get back into the correct instance of the paused service? (considering I've configured AppFabric and persistence) I somewhat understand the idea of a correlation handle, but don't think it's meant for this case.
Logging and auditing will be key for this system. I see the AppFabric makes event logs of this data, but I haven't cracked the underlying database--is it simple to use for reporting, or should I create custom logging activities to put around my actions? From experience, which would you suggest?
Thanks for any guidance you can provide. I'm happy to give further examples if necessary.
To send messages to a specific workflow instance you need to set up message correlation between your different Receive activities. In order to do that you need some unique value as part of your message data.
The Appfabric logging works well but if you want to create custom a custom logging solution you don't need to add activities to your workflow. Instead you create a custom TrackingParticipant to do the work for you. How you store the data is then up to you.
Your scenario is very similar to the one I used for the Introduction to Workflow Services Hands On Lab in the Visual Studio 2010 Training Kit. I suggest you take a look at the hands on lab or the Windows Server AppFabric / Workflow Services Demo - Contoso HR sample code.
Related
I am working on a small project trying to control some steps of a workflow in a web application using MS teams. My idea is to use R as an intermediate step between the application (which has a number of API endpoints I can call from R) and Microsoft Teams chats (or channels). Users would then use a set of keywords in the chat to lead to an action in the application. For example they might use "publish ABC-123" in a specific chat and this would lead to the application publishing document ABC-123 somewhere via R which would orchestrate everything.
I have a couple of ideas but there are drawbacks:
I thought originally about using microsoft365r. We have an app registered in Microsoft 365 which would allow us to monitor a specific chat for messages that trigger actions in R. The problem with this approach is that we would need to have the R code running and checking MS Teams every couple of minutes. It is certainly doable, but not very elegant.
Another option could be setting up a plumber API and an outgoing webhook in MS Teams. This seems like the ideal way to do it, but webhooks in MS Teams require https and as far as I understand this is not straightforward to implement in plumber.
I would appreciate any ideas on how to do this. I know I am not very specific, but mostly looking for high level pointers of what I could look at. Many thanks!
You actually have a bunch of options for this:
Create a bot directly in code, e.g. per https://learn.microsoft.com/en-us/microsoftteams/platform/bots/what-are-bots . There's a bit of a learning curve of course, and it depends on whether you have development skills outside of r, e.g. python, .net, whatever. The bot would then call your code as needed.
Create a no-code bot using Power Virtual Agents. This is the equivalent, for bots, of Power Apps or Power Automate, if you're familiar with those.
Create a workflow, either in Power Automate or Azure Logic Apps, that can listen for and respond to messages. This is kind of similar to a bot, but with finer scope (and therefore less capability). If you want it to call out to your app, e.g. to an endpoint, you'd need a Premium Connecter for Power Automate, or you can use an Azure Logic App directly (uses the same engine, but the pricing model is different for these and Power Automate is a little easier to work with.
Outgoing webhook - you can implement these as standalone, but actually from your use case it sounds like a bot would be better anyway, and it's kind of what you need to build to make this kind of webhook work properly anyway.
I have been given access to a real time data feed which provides location information, and I would like to build a website around this, but I am a little unsure on what architecture to use to achieve my needs.
Unfortunately the feed I have access to will only allow a single connection per IP address, therefore building a website that talks directly to the feed is out - as each user would generate a new request, which would be rejected. It would also be desirable to perform some pre-processing on the data, so I guess I will need some kind of back end which retrieves the data, processes it, then makes it available to a website.
From a front end connection perspective, web services sounds like it may work, but would this also create multiple connections to the feed for each user? I would also like the back end connection to be persistent, so that data is retrieved and processed even when the site is not being visited, I believe IIS will recycle web services and websites when they are idle?
I would like to keep the design fairly flexible - in future I will be adding some mobile clients, so the API needs to support remote connections.
The simple solution would have been to log all the processed data to a database, which could then be picked up by the website, but this loses the real-time aspect of the data. Ideally I would be looking to push the data to the website every time the data changes or now data is received.
What is the best way of achieving this, and what technologies are there out there that may assist here? Comet architecture sounds close to what I need, but that would require building a back end that can handle multiple web based queries at once, which seems like quite a task.
Ideally I would be looking for a C# / ASP.NET based solution with Javascript client side, although I guess this question is more based on architecture and concepts than technological implementations of these.
Thanks in advance for all advice!
Realtime Data Consumer
The simplest solution would seem to be having one component that is dedicated to reading the realtime feed. It could then publish the received data on to a queue (or multiple queues) for consumption by other components within your architecture.
This component (A) would be a standalone process, maybe a service.
Queue consumers
The queue(s) can be read by:
a component (B) dedicated to persisting data for future retrieval or querying. If the amount of data is large you could add more components that read from the persistence queue.
a component (C) that publishes the data directly to any connected subscribers. It could also do some processing, but if you are looking at doing large amounts of processing you may need multiple components that perform this task.
Realtime web technology components (D)
If you are using a .NET stack then it seems like SignalR is getting the most traction. You could also look at XSockets (there are more options in my realtime web tech guide. Just search for '.NET'.
You'll want to use signalR to manage subscriptions and then to publish messages to registered client (PubSub - this SO post seems relevant, maybe you can ask for a bit more info).
You could also look at offloading the PubSub component to a hosted service such as Pusher, who I work for. This will handle managing subscriptions and component C would just need to publish data to an appropriate channel. There are other options all listed in the realtime web tech guide.
All these components come with a JavaScript library.
Summary
Components:
A - .NET service - that publishes info to queue(s)
Queues - MSMQ, NServiceBus etc.
B - Could also be a simple .NET service that reads a queue.
C - this really depends on D since some realtime web technologies will be able to directly integrate. But it could also just be a simple .NET service that reads a queue.
D - Realtime web technology that offers a simple way of routing information to subscribers (PubSub).
If you provide any more info I'll update my answer.
A good solution to this would be something like http://rubyeventmachine.com/ or http://nodejs.org/ . It's not asp.net, but it can easily solve the issue of distributing real time data to other users. Since user connections, subscriptions and broadcasting to channels are built in to each, that will make coding the rest super simple. Your clients would just connect over standard tcp.
If you needed clients to poll for updates then you would need a que system to store info for the next request. That could be a simple array, or a more complicated que system depending on your requirements and number of users.
There may be solutions for .net that I am not aware of that do the same thing, but those are the 2 I know of.
I have an existing asp.net application that is currently in production for more than 3 years now. That application was developped based on internal and user requirements. That application is also using Google Analytics to detect different usage metrics to understand more what users are doing and which part of the system is most requested. But... we understand now that we are not so well connected to client's need's and more importantly, we don't receive a lot of feedback from them and when we receive feedback, that feedback is sent to many different people so most of the time they are lost or missing some valuable informations. Here is my question: is there some free (or paid) products that can be incorporated into an existing asp.net application that can provide the following functionnalities:
For my users:
Send feedbacks
Log bugs
Submit feature request
Ask questions
Be able to follow an issue, bug or feature and subscribe to it
Be able to rate answers
Be able to include attachments
Be able to vote for issues to prioritize them
Etc.
For me:
Respond to all of these issues and be able, in some way, to see and analyze all of this data to properly populate our product backlog with what user needs
My real need will be to have something like Telerik has implemented. Is there something that can be incorporated into an existing application?
Thanks in advance
What about User Voice? It's a great system to collect user feedback. Not sure if you'd get the integration you're looking for. For the rest of your requirements it seems it would work really well.
I'm developing a software system which receives information (which is saved to a database) and when any information is received (new insert in a specific table) an alert should be seen in the screen in the information center, so proper action can be taken.
I'm writing an application with ASPNET MVC, SQL Server 2008 Express, SQL Agent free for that version of SQL Server, Entity Framework 4, Visual Studio 2010, etc.
Right now, I've set the database and a SQL job that monitors the table each minute, if there is a new records an email is sent to same addresses. My problem is...What then? Which would be the best architecture to follow?
A couple of option I thought about are:
1) In the job connect to a web service and that web service an the web service can open a popup
2) The web page could be pooling the database table to know if there are new records
Is there any way to make push to the web page instead of the page pooling the database server?
I know maybe windows application would fit better here, but right now I must stick with ASPNET MVC as I already started and don't want to create another application.
Thanks! Daniel
Is there any way to make push to the web page instead of the page pooling the database server?
HTML5 WebSockets. Draft, pretty new, specification is still subject to change, to all browsers implement it. You will need a WebSocket Server. If you go that route make sure you read this guy's blog. He is behind Laharsub which is a must try server.
I'm pretty sure you are able to use Silverlight to push data down to the client. Here is a pretty good overview that I read a while back. HTML5 might be a better way to go. But with such limited support it's almost not worth it at this point. Granted the Silverlight application might be out of reach to, but it's still a possibility.
I would suggest that you look into (complex) event processing, or stream processing -- at least to get the feeling for architecture of these systems.
The idea is to capture a stream of events before they reach database, route them (process) within the event processor and put them in the DB from there -- treating the DB as only one of event destinations (subscribers).
Take a look at Streambase, ruleCore, and many others.
These were all developed for the type of scenario you described.
Try to see the problem from the other angle. Develop a web client that reads the database every minute and compare to last pull ...
I'm building UI logging into a long-existing ASP.NET enterprise application. I have my own ideas of how to progress from here and am continuing to research & design. But I'd love to hear some details from the SO community.
Here are the details, assumptions and questions as of right now, subject to evolve within the enterprise as well as whatever input comes in here on SO:
Would prefer to have a consistent DB connection since there will be a lot of activity
Will probably use the ThreadPool, but will this conflict too much with ASP.NET vying for threads?
Possibly use in-memory queue (Queue) for logging batches of inputs periodically? (one per domain)
Will need to be configurable. IE: Could log all page events during their normal postback calls, or hook individual control actions or events to being logged whether there's a postback or not. IE: User collapses a panel.
All "high-visibility" UI events that'll already be posting back as well as other events that won't necessarilly post back right away. Have a client batch of events and send occasionally?
How do we minimize the impact on existing code?
Have "fly on the wall" AJAX functionality that posts back accordingly? It'll basically be watching all that's been configured to be logged.
Logging must be ordered for reporting a user's step-by-step progress from point A to B in a workflow.
How about a WCF service that does the actual logging, paired with a PostSharp attribute. In your PostSharp attribute you can call asynchronously to you WCF service while your application hums along. I've implemented something like this in past projects and it works great with little if no slowing down.
http://www.postsharp.org/
Why not use log4net? You could capture a userid, sessionid, and any additional information you need to track step-by-step progress. You could configure the levels so that you could reduce the logging if it impacted performance. I wouldn't consider re-inventing the wheel by writing your own framework when there are several viable existing logging frameworks.