In order to test how a REST service performs under load I would like to send production data to two service end points, one production service and one test service. I would like the responses from the test service to be ignored so the client has no idea it's request is being sent to 2 services. I would like something in between the client and the service so that I do not need to make any changes to either, just have some sort of additional 'filter' service that the traffic will go through which will then pass the request on untouched but also send a duplicate request to the test service. Someone suggested that I might be able to do this using Apache Camel but it's a bit overwhelming and I don't want to get started learning Camel if my aim is not possible. Has anyone achieved anything similar, either using Camel or some other method?
This can be done by defining a jetty or a cxf endpoint that acts as a proxy routing the request to two other http endpoints ie, the REST services.
from("jetty:http://somehost:8282/xxx").
to("http://prod:8181/rest/service/xyz").
to("http://test:8182/rest/service/xyz");
The client can fire the load to http://somehost:8282/xxx. The client will not be aware that it is being routed to two services.
Note: The test will not yeild a real load result if you are routing the client request to two services via the above route or other proxy/router methodologies. Because some latency will be introduced by the proxy/route itself. Instead i suggest to use some load test tool to generate the load and directly fire to the prod and test endpoints separately.
For example, apache ab benchmark tool. Take a look at this and this.
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.
There's one point in ASP.NET Core that I believe I didn't fully understand yet and that is the idea of request features. As explained in the docs:
Feature interfaces define specific HTTP features that a given request may support. Servers define collections of features, and the initial set of features supported by that server, but middleware can be used to enhance these features.
My initial understanding about this was that request features are all things a server should expose to be used on the application pipeline. That is, behaviors that a server should perform like sending a file.
On the other hand, there's, for example, the authentication request feature. Now, I'm not sure authentication falls into this category. It doesn't seem like some server behavior that the application should call, but rather, a concern of the application itself.
This makes me wonder what really makes something be a request feature. So, what makes something be a request feature in ASP.NET Core? Is my initial understanding wrong? What is behind the decision of making something a request feature?
My initial understanding about this was that request features are all things a server should expose to be used on the application pipeline. That is, behaviors that a server should perform like sending a file.
That's one use of http features. It's also a way to augment or light up behaviors on the HttpContext, like buffering, send file, authentication, websockets.
Middleware can also add features specific to that middleware, you can see examples of this:
The exception handler middleware flows the exception that occurred via a request feature - https://github.com/aspnet/Diagnostics/blob/dev/src/Microsoft.AspNetCore.Diagnostics.Abstractions/IExceptionHandlerFeature.cs.
The routing middleware adds route data to the current http context via a request feature - https://github.com/aspnet/Routing/blob/dev/src/Microsoft.AspNetCore.Routing.Abstractions/IRoutingFeature.cs
Generally it's a way to flow per request behavior and state from the server, through middleware, to the application.
Can I get a list of target endpoints in a javascript policy?
Let's say I have a proxy endpoint that connects to multiple target endpoints. Can I write a javascript policy so that if a request is made to a specific url on that proxy, it will make a call to all the target endpoints and aggregate the results?
Yes that's possible. The apiproxy definition itself holds all the target endpoints defined for it.
For example:
curl -v https://api.enterprise.apigee.com/v1/o/{org}/apis/{api}/revisions/{rev}/targets
would give you the list of all targets.
Then you can get each target URL from the list by calling:
curl -v https://api.enterprise.apigee.com/v1/o/{org}/apis/{api}/revisions/{rev}/targets/{target}
You can parse out each URL in a for loop and then make a request to each of these URLs. If your requests a simple GET calls without any variation in the request object like headers, body etc. then a simple for loop would be good enough.
For example:
var geocoding = httpClient.get(URL);
context.session["geocoding"] = geocoding;
This piece of code can be called in a loop for all the target endpoints that you might have.
The only catch here is that, to get the target endpoints you are making a management api call from the runtime layer. Which means if at any point of time the Apigee management layer is down for maintenance or experiencing degraded service due to scheduled maintenance, your runtime calls would tend to fail. The other solution could be to isolate the two scripts:
Get the list of endpoints in one javascript and maybe store the URLs in cache (populateCache policy) or keyvaluemaps (given that proxy endpoint URLs won't change too often)
Read the list of endpoints from cache or kvm and then trigger another javascript that can make calls to these endpoints and then aggregate the response.
There is not a way to call a target endpoint from JavaScript. In fact, you can only call 0 or 1 target endpoints for a single call to the proxy, not multiple target endpoints.
You can call make multiple HTTP requests from within JavaScript using httpClient, and aggregate the results, but not target endpoints. An example of this is found here.
I'm looking into building an ASP.NET MVC application that exposes (other than the usual HTML pages) JSON and XML REST services, as well as Web Sockets.
In a perfect world, I would be able to use the same URLs for the Web Sockets interface as I do for the other services (and determine which data to return by what the user agent requests) but, knowing that IIS wasn't built for persistent connections, I need to know if there's a way that I can accept (and possibly even handshake) the Web Sockets connection and then pass the connection off to another service running on the server.
I do have a workaround in mind if this isn't possible that basically involves using ASP.NET to check for the Web Sockets connection upgrade headers, and responding with a HTTP/1.1 302 Found that points to a different host that has my Web Sockets service configured to directly listen to the appopriate endpoint(s).
If I completely understand your goal, I believe you can use the IIS7/7.5 Application Request Routing module to accomplish this.
Here's a quick reference: http://learn.iis.net/page.aspx/489/using-the-application-request-routing-module/
Rather than 302 responses you could use ISAPI_rewrite to direct to an appropriate endpoint (and manipulate the HTTP header to get it there)
http://www.isapirewrite.com/docs/
Otherwise no, IIS cannot natively pass off an HTTP connection. The current MSFT method is to use a 302 or something else that is intercepting the raw socket and performing header manipulation prior to sending to IIS (or whatever other application)
It strikes me that this would be a better question to ask Microsoft than to ask us. Web Sockets is new technology, and rather than looking for a hack, you might want to ask Microsoft how they plan to support it. IIS is their software. Poke around on http://iis.net (maybe in http://forums.iis.net) and see what you learn.
The way to do this is to use a unique Session ID that is associated with the Http Session. From the description, it seems like you might want to scope this to a single HttpApplication instance, but this is not necessary (you may also persist a session across many application instances). Anyway, this session ID needs to be attached somehow to each Http Request (either with a cookie, querystring, static variable with the HttpApplication instance, form data). Then you persist the identifying information about the Http session somewhere with the ID.
This identifying information may vary depending on your needs but could entail the entire http request or just some stripped down representation that serves your particular purpose.
Using this SessionID somewhere in the Http request allows you to restore whatever information you need to call and interact with the appropriate services. The instances of the services may also need to be scoped to the session as well.
Basically, what I am suggesting is that you NOT directly pass the Http connection to an external process, but instead pass the necessary data to the external process, and allow create a mechanism for sending callback data. I think looking into the mediator pattern may be helpful for you in understanding what I mean here. http://en.wikipedia.org/wiki/Mediator_pattern . I hope this helps.
Our web services are distributed across different servers for various reasons (such as decreasing latency to the client), and they're not always all up-to-date. Rather than throwing an exception when a method doesn't exist because the particular web service is too old, it would be nicer if we could have the client check if the service responds to a given method before calling it, and otherwise disable the feature (or work around it).
Is there a way to do that?
Get the WSDL (append ?wsdl to the URL) - you can parse that any way you like.
Unit test the web service to ensure its signatures don't break. When you write code that breaks the method signature, you'll know and can adjust the other applications accordingly.
Or just don't break the web services and publish them in a way that enable syou to version them. As in http://services.domain.com/MyService/V1.1/Service.asmx (for .NET) so that way your applications that use v1.1 won't break when you publish v1.2 and make breaking changes.
I would also check out using an internal UDDI server if it's really that big of a hasle to manage your web services. Using the Green Pages of UDDI will tell you what you want to know about the service.
When you are making a SOAP request you are just sending an HTTP request to a server. If the server understands it, it will respond with an HTTP 200 and some XML back, if it doesn't it will send you some error HTTP code (404, 500, ...)
There is no general way to ask for the existance of a "method" exposed by a web service. Try to use the WSDL exposed if it is automatic, or just try to use the "method" and check for an error in the response (you don't have to send an exception to the user...)
Also, I don't know if I understood you well, but you are thinking of quering the server twice, once to check if the method exists, and second to make the actual call it if it does? I would just check for the error if it doesn't, and proceed normally if it does.