Determining the set of message destinations at runtime in BizTalk application - biztalk

I’m a complete newbie at BizTalk and I need to create a BizTalk 2006 application which broadcasts messages in a specific way. I’m not asking for a complete solution, but for advise and guidelines, which capabilities of BizTalk I should use.
There’s a message source, for simplicity, say, a directory where the user adds files to publish them. There are several subscribers, each having a directory to receive published files. The number of subscribers can vary in the course of exploitation of the program. There are also some rules which determine if a particular subscriber needs to receive a particular file, based on the filename. For example, each subscriber has a pattern or mask of filename which files they receives must match. Those rules (for example, patterns) can change in time as well.
I don’t know how to do this. Create a set of send ports at runtime, each for each destination? Is it possible? Use one port changing its binding? Would it work correctly with concurrent sendings? Are there other ways?
EDIT
I realized my question may be to obscure and general to prefer one answer over another to accept. So I just upvoted them.

You could look at using dynamic send ports to achieve this - if your subscribers are truly dynamic. This introduces a bit of complexity since you'll need to use an orchestration to configure the send port's properties based on your rules.
If you can, try and remove the complexity. If you know that you don't need to be truly dynamic when adding subscribers (i.e. a subscriber and it's rules can be configured one time only) and you have a manageable number of subscribers then I would suggest configuring each subscriber using it's own send port and use a filter to create subscriptions based on message context properties. The beauty of this approach is that you don't need to create and deploy an orchestration and this becomes a highly performant and scalable solution.

If the changes to the destination are going to be frequent, you are right in seeking a more dynamic solution. One nice solution is using dynamic send ports and the Business Rules Engine. You create rule set for the messages you are receving. This could be based on a destination property or customer ID in the message. Using these facts, the rules engine can return a bunch of information like file mask, server name, ip address of deleiver server, etc. You can thenuse this information to configure the dynamic send in the orchestration. The real nice thing here is that you can update the rule set in the rules engine without redeploying the whole solution. As a newb, these are some advanced concepts, but not as diificult as you may think.
For a simpler solution, you might want to look at setting the FILE Send adapters properties via it's Propery Schema (ie. File name, Directory, etc.). You could pull these values from a database with a helper class inside an expresison shape. On each message ogig out, use the property shcema to set where the message will be sent and named. This way, you just update the database as things change.
Good Luck!

Related

Routing/filtering messages without orchestrations

A lot of our use cases for Biztalk involve simply mapping and routing HL7 2.x messages from one system to another. Implementing maps and associating them to send/recieve ports is generally straightforward, but we also need to do some content based filtering on the sending side.
For example, we may want to only send ADT A04 and ADT A08 messages to system X if the sending facility is any 200 facilities (out of a possible 1000 facilities we have in our organization), but System Y needs ADT A04, A05, A8 for a totally different set of facilities and only for renal patients.
Because we're just routing messages and not really managing business processes here, utilzing orchestrations for the sole purpose to call out to the business rule engine is a little overkill here, especially considering that we'd probably need a seperate orchestration for each ADT type because of how schemas work. Is it possible to implement filter rules like this without using using orchestrations? The filters functionality of send ports looks a little too rudimentary for what we need, but at the same time I'd rather not develop and manage orchestrations.
You might be able to do this with property schemas...
You need to create a property schema and include the properties (from the other schemas) that you want to use for routing. Once you deploy the schema, those properties will be available for use as a filter in the send port. Start from here, you should be able to find examples somewhere...
As others have suggested you can use a custom pipeline component to call the Business Rules Engine.
And rather then trying to create your own, there is already an open source one available called the BizTalk Business Rules Engine Pipeline Framework
By calling BRE from the pipeline you can create complex rules which then set simple context properties on which you can route your messages.
Full disclosure: I've worked with the author of that framework when we were both at the same company.

How to find the Port ID in Biztalk 2010?

I have configured a receiving port named it "SalesOrder" It contains a receiving location of File Type.
Now when i use this receiving port in a Send port i define a filter like this :
BTS.ReceivePortName==SalesOrder
I start the ports and it works just fine.
Now question is if i want to us the filter like this :
BTS.ReceivePortID=="Where do i get the Port ID"
How can i find the PortID in Biztalk 2010.
There isn't an easy way of getting to the ReceivePortID. The id will also change when creating, deleting, setting up new port and of course as you move you configuration between environments. It's much more common practice to set up these kind of filter based on ReceivePortName instead as this (hopefully) doesn't change as much.
Best practice in my opinion is however to not use these kind of filters that are tied to the configuration but to rather set up filters based on message types and order other promoted properties. Using promoted properties over configuration will also create a more flexible and more loosely coupled solution.

BizTalk custom adaptor

I am not sure if I ask the right question, but this is the scenario I am trying to run:
Multiple files (XML and a few related files, "attachments") have to get into BizTalk as a single message. I have looked into existing adapters, and don't see that done with existing once. To be more accurate, files are taken from file system. Files are not found at the same time, but arrive one at a time, when order is not ensured. XML (content) file is the one that knows what attachments it has to have (what other files).
We are looking into BizTalk 2009 and I was wondering would be that responsibility of a custom Adaptor, or something else. And were I could look for samples.
Thanks.
It is probably possible to do what you want using a custom adapter, though I'd recommend against it. You can achieve what you require using orchestration.
What you are looking for is likey a convoy, or at the least some use of correlation.
In BizTalk a convoy is a messaging pattern (as opposed a BizTalk feature) that allows groups of messages to be processed by a single orchestration.
You essentially use correlation on a receive port to group messages together in either a parallel (what you probably want) or sequential fashion.
There is an article [here](http://msdn.microsoft.com/en-us/library/ms942189(BTS.10\).aspx) by Stephen W. Thomas about convoys (it is for BT 2004 but the concepts still hold) and there is a lot of additional information on the web and in books (Professional BizTalk server 2006 has a subsection on them)
Without more details on your scenario it is hard to know exactly how the convoy would be built but below are two approaches to look at (also, I've not had a chance to properly use BT2009 so there may be extended support for correlation scenarios that help you out).
Flexible Correlation
If you don't know anything about the files listed in the context XML you will probably need a pattern like the one described by Charles Young in this post.
Non-uniform sequential convoy
If you do have a little bit of info before hand one way might be as follows (basically a Non-uniform sequential convoy):
This makes the assumption that there is some way of linking all the files together so you can correlate them.
Create a single orchestration that subscribes to you inbound receive port (which contains the file receive location).
This orchestration will have a single activation receive shape that is set up for your content file.
Once the orchestration is started by a content file a second correlated receive shape starts picking up the messages that match that content file. (this second receive could possible be in a loop to allow for variable numbers of files)
You then pack them all together into a single outbound file of your design and send them out once the full number of files has been received.
Seems to me a better approach would be to implement the above requirements with a combination of a custom pipeline component and/or a custom adapter. I assume you do not really need to manipulate the incoming files - except for the content XML file - or that you couldn't since they are in binary format. This calls for a custom pipeline component.
What you can do is develop a custom BizTalk adapter to interact with the file system and to implement the listening and looping logic. Next you can develop a custom pipeline component to create a single BizTalk message perhaps with base64 data type in it for binary data. Additionally you could also promote messages right in this component to enable orchestration subscriptions.
Orchestrations are more suited for implementing business work-flow scenarios where the messages are already in XML format. This do not appear to be the case. In any case I think at the very least a custom pipeline component would be needed.
David's answer is the correct answer.
Even in cases where you don't know absolutely nothing about the contents of the expected attachments, surely you know their names and locations. Therefore you can use the Flexible Correlation linked to in david's answer like this:
The key to the solution is to correlate on the builtin BTS.ReceivedFileName property.
First, create a custom receive pipeline, with a custom pipeline component that promotes the BTS.ReceivedFileName context property of the received messages. This simple custom component is fairly easy to write but you can make it straightforward by using third-party frameworks such as, (shameless plug, here) my PipelineComponentBase class or the excellent BizTalk Server Pipeline Component Wizard.
Now for the easy part:
Attachments are received in a specific location, designated by its path on the filesystem.
Create a receive location that listens to an alternate location, used only to control when files are actually swallowed by BizTalk.
In your orchestration, create a correlation type with the BTS.ReceivedFileName property and a correlation set base on this correlation type.
When you want to receive binary attachments, send a dummy message with the BTS.ReceivedFileName context property set to the filename of the binary attachment but with the path matching the alternate location ; the one used by the receive location. Initialize the correlation on the send shape.
Use an expression shape to copy the binary file from its original location to the one used by the receive location.
Finally, use a receive shape bound to the receive port that contains the receive location whose custom receive pipeline will promote the BTS.ReceivedFileName property.
Notice that you actually need to send a message in order to initialize the correlation. It does not matter what message you send actually. What I'd do is send the message through a send pipeline that contains an empty pipeline component. That is a pipeline component that reads the message but return null (so that the message vanishes into thin air before it reaches the adapter). A more elaborate solution would be to use a null adapter. That is an adapter that reads the message but does not do anything about it.
These two solutions avoid having many files accumulate in a temporary location somewhere, just for the sake of initializing a correlation!

How can I implement an IRC Server with 'owned' nicknames?

Recently, I've been reading up on the IRC protocol (RFCs 1459, 2810-2813), and I was thinking of implementing my own server.
I'm not necessarily looking into adhering religiously to the IRC protocol (I'm doing this for fun, after all), but one of the things I do like about it is that a network can consist of multiple servers transparently.
There are a number of things I don't like about the protocol or the IRC specification. The first is that nicknames aren't owned. While services like NickServ exist, they're not part of the official protocol. On the other hand, implementing something like NickServ properly kind of defeats the purpose of distribution (i.e. there'd be one place where NickServ is running, and one data store for it).
I was hoping there'd be a way to manage nicknames on a per-server basis. The problem with this is that if you have two servers that have some registered nicknames, and they then link up, you can have collisions.
Is there a way to avoid this, without using one central data store? That is: is it possible to keep the servers loosely connected (such that they each exist as an independent entity, but can also connect to one another) and maintain uniqueness amongst nicknames?
I realize this question is vague, but I can't think of a better way of wording it. I'm looking more for suggestions than I am for actual yes/no answers. So if anyone has any ideas as to how to accomplish nickname uniqueness in a network while still maintaining server independence, I'd be interested in hearing it. Note that adhering strictly to the IRC protocol isn't at all necessary; I've got no problem changing things to suit my purposes. :)
There's a simple solution if you don't care about strictly implementing an IRC server, but rather implementing a distributed message system that's like IRC, but not exactly IRC.
The simple solution is to use nicknames in the form "nick#host", much like email. So instead of merely being "mipadi", my nickname could be "mipadi#free-memorys-server.net". So I register with just your server, but when your server links up with others to form another a big ole' chat network, you can easily union all the usernames together. There might be a "mipadi" on otherserver.net, but then our nicknames become "mipadi#free-memorys-server.net" and "mipadi#otherserver.net", and everything is cool.
Of course, this deviates a good deal from IRC. :)
They have to be aware of each other. If not, you cannot prevent the sharing of nicknames. If they are, you simply need to transfer updates on the back-end. To prevent simultaneous registrations, you need a transaction system that blocks, requests permission from all other servers, and responds.
To prevent simultaneous registrations during outages, you have no choice but to timestamp the registration, and remove all but the last (or a random for truly simultaneous) registered copy of the nick.
It's not very pretty considering these servers aren't initially merged in the first place.
You could still implement nick ownership without a central instance, if your server instances trust each other.
When a user registers a nick, it is registered with the current server he's connected with
When a server receives a registration that it didn't know of, it forwards that information to all other servers that don't know it yet (might need a smart algorithm to avoid spamming the network)
When a server re-connects to another server then it tries to synchronize the list of registered nicks and which server handles which nick
If there is a collision during that sync, then the older registration is used, and the newer one marked as invalid
If you can't trust your servers, then it'll get a lot harder, as a servers could easily claim every username and even claim the oldest registration for each one.
Since you are trying to come up with something new, the idea that springs to mind, is simply including something unique about the server as part of the nick name when communicating outside of the server. So if you want to message a user on a different server you might have something like user#server
If you don't need them to be completely separate you might want to consider creating some kind of multiple-master replicated database of accounts. Where each server stores a complete copy of the account database, and each server can create new accounts which will be replicated to other servers as possible. You'll probably still have to deal with collisions on occasion though.
While services like NickServ exist, they're not part of the official protocol.
Services are not part of the official protocol because they've nothing to do with the protocol. They're bots with permissions. There's no reason why you couldn't have one running on each server but it does make them harder to maintain.
If you were to go down that path, I would probably suggest the commonly used "multiple master" database replication technique. If one receives a write (in your case, a new user is created or updated, etc) it sends the data to all the other nodes. You'll have to be careful though. If one node is offline when the others get an update, it will need to know to resync on reconnection.
Another technique would be as above but in reverse. Data is only exchanged between nodes when it's needed. Eg if a user tries to log in on a node where there's no data for it, it'll query the others and issue a move order to get all the data to that one node. This is potentially less painful than the replication version but there could be severe problems in netsplits if somebody signs up on a node disconnected from the pack for a duplicate nick.
One technique to nullify the problems of netsplits would be to make chat nodes and their bots netsplit-aware. When they're split, they probably shouldn't allow any write actions... But this could impact on your network if you're splitting lots.
You've also got to ask how secure this might or might not be. IRC network nodes are distributed for performance but they're not "secure". Because of this, service bots are usually run centrally to keep ultimate control over their running. If you distributed the bots and remote node got hacked, they'd potentially have access to the whole user database (depending on the model).

Is it wrong to switch client logic in the service tier?

We have two client apps (a web app and an agent app) accessing methods on the same service, but with slightly different requirements. My team wants to control behaviour on the service side by passing in a ApplicationType parameter to every method - which is essentially an enum containing the name of the calling client application - which is then used as a key for a database lookup to configure the service with client-specific options.
Something about this makes me uneasy as I don't think the service should really have to be aware of which client is calling it. I'm being told that it's easier to do it this way than pass a load of options dynamically through the method call.
Is there anything wrong with the client application telling the service who they are? Or is there really no difference between passing a config key versus a set of parameterized options?
One immediate problem I can see is that if we ever opened the service to another client run by a third party, we'd have to maintain their configuration settings locally for them. At the moment we own both client apps so it's not so much of a problem.
How would you do it?
In a layered solution, you should always consider your layers as onion-like layers, and dependencies should always go inwards, never outwards.
So your GUI/App layer should depend on the businesslogic layer, the businesslogic layer should depend on the data access layer, and similar.
Unless you categorize the clients (web, win, wpf, cli), or generalize it with client profiles (which client applications can configure), I would never pass in the name of the calling application, as this would make the business logic layer aware of and dependent upon the outside layer.
What kind of differences are we talking about that would depend on the type of application? If you elaborate a bit on the differences here, perhaps someone can come up with some helpful advice on other ways to solve this.
But I would definitely look for other ways before going down your described path.
Can't you create two different services, one for each application? The two services will share a lot of code or call a single internal service with different parameterization depending on what outer service was called.
From a design perspective, this is no different than having users with different profiles. From a security perspective, I hope your applications are doing something to identify themselves, lest users of one application figure out a way to invoke the other applications logic as a hack. (Image a HR application being used by the mafia and a bank at the same time, one customer would be interesting in hacking the other customer's application on a shared application host)
In .net the design doesn't feel this way because the credentials live on the thread (i.e. when you set the IIPrincipal, that info rides on the thread-- it is communicated along with each method call, but not as a parameter.)
Maybe what you are looking for in terms of a more elegant design is an ApplicationIdentity attribute. You'd have to write a custom one, I don't know of one in the framework right now.
This is a hard topic to discuss without a solid example.
You are right for feeling that way. Sending in the client type to change behaviour is not correct. It's not a bad idea for logging... but that's about it.
Here is what I would do:
Review each method to see what needs to be different and why.
Create different methods for different usages. The method name should be self explanatory. If you ever need to break compatibility, you have more control (assuming you're not using a versioning system which would be overkill for an in-house-only service).
In some cases request parameters (flags/enum values) are more appropriate.
In some cases knowing the operating environment is more appropriate (especially for data security). The operating environment almost always sent during a login request. Something like "attended"/"secure" (agent client) vs "unattended"/"not secure" (web client). Now you must exchange a session key (HTTP cookie or an application level session id). Sessions obviously doesn't work if you need to be 100% stateless -- especially if you want to scale-out without session replication... if you have that requirement, send a structure in every request.
Think of requests like functions in your code. You wouldn't put a magic parameter that changes the behaviour of the function. You would create multiple functions that each behave differently. Whoever is using the function makes the decision which one to call.
So why is client type so wrong? Client type has no specific meaning on its own. It has many meanings and they may change over time. It's simply informational which is why it is a handy thing to log. An operating environment does have a specific meaning.
Here is a scenario to consider: What if a new client type is developed that is slightly different in a way that would break compatibility with the original request? Now you have two requests. 2 clients use Request A and 1 client uses Request B. If you pass in a client type to each request, the server is expected to work for every possible client type. Much harder to test and maintain!!

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