I am using the latest version of SignalR and Crank.
I want to use the standard switches to spin up multiple simulated clients. Thus: /NumClients:N and /ControllerUrl:URL. I don't understand why I have to specify the second option when I specify the number of clients, N. I see that a single "controller hub" is started, but I don't understand why. What is it's purpose? What is it controlling?
When you use multiple clients, you have to pick one client, which will be responsible for collection of information. To achieve this, Crank try to spin own mini hub to which all other clients will connect and report information (and if you don't provide ControllerUrl which has to create this internal hub will fail).
At least, this is what I understood from reading the code.
Related
So I've this Microservice architecture where there is an ApiGateway, 2 microservices i.e., Configurations. API and API-1. The Configuration. API is mainly responsible to parse the JSON request and
access the DB and update Status tables, also to fetch required data, it even adds up more values to the JSON request and send it to the API-1. API-1 is responsible to just generate report based on the json passed.
Yes I can merge the configurations. API to the API-1 and make it a single service/container but the requirement is not to merge and create two different components i.e., 1 component purely based on
fetching the data, updating the status while the other just to generate the reports.
So here are some questions:
: Should I use gRPC for the configuration.API or is there a better way to achieve this.
Thank you.
RPC is a synchronous communication so you have to come up with strong reason to use it in service to service communication. it brings the fast and performant communication on the table but also coupling to the services. if you insist use rpc it is better to use MASSTRANSIT to implement the rpc in less coupled way. however in most cases the asynchronous event-base communication is recommended to avoid coupling (in that case look at CAP theory, SAGA, circuit breaker ).
since you said
but the requirement is not to merege and create two different
components
and that is your reason and also base on the fact
also to fetch requried data, it even adds up more values to the JSON
request and send it to the API-1
i think the second one makes scenes more. how ever i cant understand why you change the database position since you said the configuration service is responsible for that.
if your report service needs request huge data to generate report you have to think about the design. there is no more profile on you domain so there cannot be an absolute answer to this. but consider data reduce from insertion or request or some sort of pre-calculation if you could and also caching responses.
The middletier and edge tier are in separate folders and packages, so I can't simply call say a middletier class from an edgetier class. How do I communicate between these two tiers? Thanks.
In the said example both those components run on servers (Jetty and Netty). You should just pass REST calls between them to communicate. For instance, you can fire up both servers and then issue a GET request from one component to the other, and have the other listen for the request and perform actions accordingly. Hope this helps.
If I need to build a specialized web app to be able to terminate messages processed by specific send ports, WMI is one option. Are there others? and are there pros/cons to each approach?
You should be able to terminate messages programmatically by referencing the Microsoft.BizTalk.Operations.dll assembly. That will allow you to use the TerminateInstance method of the BizTalkOperations Class, which allows you to reference a remote BizTalk instance (using this constructor) without enabling remote WMI administrative access.
You may also need to reference Microsoft.BizTalk.Pipeline.dll in Visual Studio to get IntelliSense to work.
The BizTalk SDK includes a sample app that you can review, as well, to see how to look up a message instance, which you'll need for the parameter to the TerminateInstance method:
http://msdn.microsoft.com/en-us/library/gg163868
For example:
BizTalkOperations _operations = new BizTalkOperations()
IEnumerable messages = _operations.GetMessages();
foreach (BizTalkMessage msg in messages)
…
Have you considered the "/null" Send Port Adapter? This allows you to send messages to a "null" port, where they effectively disappear. Source code can be found here, although it hasn't been updated since BizTalk 2006 R2.
If this isn't relevant to what you are trying to achieve, maybe some additional information regarding the use case would help.
I've been searching and reading up on SignalR recently and, while I see a lot of explanation of what the difference is between Hubs and Persistent Connections I haven't been able to get my head around the next level, which is why would I choose one approach over the other?
From what I see in the Connection and Hubs section it seems that Hubs provide a topic system overlaying the lower-level persistent connections.
From the highly up-voted comment below:
Partially correct. You can get topics or groups in persistent connections as well. The big difference is dispatching different types of messages. For example you have different kinds of messages and you want to send different kinds of payloads. With persistent connections you have to embed the message type in the payload (see Raw sample) but hubs gives you the ability to do RPC over a connection (lets you call methods on on the client from the server and from the server to the client). Another big thing is model binding. Hubs allow you to pass strongly typed parameters to methods.
The example used in the documentation uses a chat room metaphor, where users can join a specific room and then only get messages from other users in the same room. More generically your code subscribes to a topic and then get just messages published to that topic. With the persistent connections you'd get all messages.
You could easily build your own topic system on top of the persistent connections, but in this case the SignalR team did the work for you already.
The main difference is that you can't do RPC with PersistentConnection, you can only send raw data. So instead of sending messages from the server like this
Clients.All.addNewMessageToPage(name, message);
you'd have to send an object with Connection.Broadcast() or Connection.Send() and then the client would have to decide what to do with that. You could, for example, send an object like this:
Connection.Broadcast(new {
method: "addNewMessageToPage",
name: "Albert",
message: "Hello"
});
And on the client, instead of simply defining
yourHub.client.addNewMessageToPage = function(name, message) {
// things and stuff
};
you'd have to add a callback to handle all incoming messages:
function addNewMessageToPage(name, message) {
// things and stuff
}
connection.received(function (data) {
var method = data.method;
window[method](data.name, data.message);
});
You'd have to do the same kind of dispatching on the server side in the OnReceived method. You'd also have to deserialize the data string there instead of receiving the strongly typed objects as you do with hub methods.
There aren't many reasons to choose PersistentConnection over Hubs. One reason I'm aware of is that it is possible to send preserialized JSON via PersistentConnection, which you can't do using hubs. In certain situations, this might be a relevant performance benefit.
Apart from that, see this quote from the documentation:
Choosing a communication model
Most applications should use the Hubs API. The Connections API could
be used in the following circumstances:
The format of the actual message sent needs to be specified.
The developer prefers to work with a messaging and dispatching model
rather than a remote invocation model.
An existing application that uses a messaging model is being ported to use SignalR.
Depending on your message structure, you might also get small perfomance benefits from using PersistentConnection.
You may want to take a look at the SignalR samples, specifically this here.
There are two ways to use SignalR: you can access it at a low level by overriding its PersistentConnection class, which gives you a lot of control over it; or you can let SignalR do all of the heavy lifting for you, by using the high level ‘Hubs’.
Persistent Connection is a lower level API, you can perform actions on more specific time when the connection is opened or closed, in most applications the Hub is the best choice
There are three major points to consider when comparing these two:
Message Format
Communication model
SignalR customization
With hubs message formatting is basically handled from you but with persistent connections the message is raw and has be tokenized and parsed back and forth. If the message size is important then also note that the payload of a persistent connection is much less that that of a hub.
When it comes to the communication model persistent connections basically have a function for sending and receiving messaging while hubs take a remote procedure call model with unique function per requirement.
When it comes to customization since persistent connections are more low level they may give you more control over customization.
I need to split a bizTalk message in the send pipeline. This is easy with disassemblers in receive pipelines, but doesn't work in send pipelines (makes sense).
So what is the recommended way to do it? The only easy way to do it is to write the outbound message to file, then reprocess it using a receive pipeline with a disassembler, and then send the generated messages through a outbound pipeline. Honestly, I don't need the additional roundtrip through the message box, but I don't want to create a custom send adapter.
Any other suggestions? Any easy way to save messages with multiple parts using the ootb file adapter?
While your solution is probably the best approach for this, you can also think about splitting the message inside of an orchestration (not the best practice) before the message even hits the send pipeline. The send pipeline is obviously designed for composition of messages and not decomposition so I would stay away from any custom code to handle this.
Here's a good article on debatching messages.
Why don't you use receive pipeline to split the messages at the first place. Anyways your solution uses receive pipeline. You don't want to write outbound message to file system and process it using receive pipeline again.