My Spring app will call couple of external APIs with each get request.
I understand that Spring can handle a large number of calls at a time.
But here I read about multithreading
REST Api with Multithreading for handling Files in Spring Boot
So I was wondering:
1. Does Spring implement multithreading out of the box?
2. Would using async http calls to the external APIs increase the performance, load tolerance of my App/RESTAPI?
thanks
Related
I want to consume a couple of rest services. Before I have used RestTemplate, but now I want to know What is main diffrences of SpringBoot FeignClient and WebClient?
when they should be used?
To be able to answer “when” one needs to understand the capabilities of each.
Spring WebClient is a non-blocking reactive client to make HTTP requests. Hence if you intend to use Spring Reactive Stream API to stream data asynchronously then this is the way to go. Think event-driven architecture. WebClient is part of the Spring WebFlux library.
[Feign]3 is a declarative REST library that uses annotations based architecture with thread-per-request model. This means that the thread will block until the feign client receives the response. The problem with the blocking code is it must wait until the consuming thread completes, hence think memory and CPU cycles.
So use Spring WebClient when needing non-blocking HTTP requests otherwise Feign due to simple usage model.
(Note: There is no reason as to why one cannot use WebClient for blocking operations but Feign is more mature and it’s annotation based model makes it easier)
The main difference is that WebClient supports Reactive calls.
You can achieve that with 3rd party feign clients like https://github.com/Playtika/feign-reactive but basically for a reactive way you should consider using WebClient with some neat async connector like Jetty. On the other hand, If you want a blocking way with minimal hassle then Feign could be your best choice.
WebClient is a non-blocking reactive.
Feign is blocking.
I want to introduce the new service in our company application which will ease some load of monolitic app. The specific of new service is that it will in scope of each request make a lot of http calls(simultaneously as well) and compose obtained data to make new calls. The question is: will I benefit from using Spring WebFlux here provided the rest of the services are synchronous(and backpressure I assume won't work)? Does it make sense at least in terms of resource consumption not to be blocking?
In a Spring Boot (2.2.2.RELEASE) application, I have reactive endpoints (returning Mono or Flux), each of them is using reactive WebClient for calling another service. This "other" service is legacy (non-reactive) one.
Here is my question:
Is there a benefit of using Webflux (reactive WebClient) if my reactive endpoint is calling this non-reactive endpoint which does blocking stuff?
Is my reactive endpoint still reactive?
If we're talking about HTTP endpoints, we can call them with blocking or non-blocking (asynchronous) clients, but not fully reactive.
If your "new" application is reactive, you have to use non-blocking client (WebClient in your case), otherwise you will block NIO-threads and loose all the advantages of the reactive approach. The fact that the “other” application is blocking doesn't matter, you can still get a less resource-intensive "new" application.
They are
1. Not fully.
2. Your request is not full reactive until you change legacy APIs
Explanation:
End-to-End Reactive pattern only help into to the performance side
Currently you’re using reactive client this helps to connect to server in two way communication.
First set of APIs are reactive so web server layer is now reactive but data layer (Legacy APIs ) not reactive
I am building a microservice using spring webflux and netty. Internally I use web client to make rest api calls. How can I control rate at which I can call rest api via webclient? I guess backnpressure is only for a single request/reply and does not work across multiple request to my microservice. Amy pointers will be appreciated.Thanks.
Resilience4j has support for non-blocking rate limiting with Reactor.
See: https://resilience4j.readme.io/docs/examples-1#decorate-mono-or-flux-with-a-ratelimiter
I'm trying to learn SI (Spring Integration) but i'm a bit confused on the real usage of this.
As first example i would like to interact with a WebService but i dont understand what could be the difference from
Invoke a WebService Using SI
Invoke a Webservice using RestTemplate
So, what is the benefit of using SI (in Webservice context, or in other context)?
Looking the web, i havent find an article that explain:
Usually you will do in this way....
With SI you can do better - in this another way - and the benefit are....
To be more explicit on what i have to realize, this is an example:
1) I have to write an application (Standalone application) that have to collect some data in the system periodically and then invoke a Web Service that will store it.
2) The Web Service receive the call from the "clients" and store in the database.
My webservice will use REST.
The reason because i've think to use SI is that the Standalone Application should interact with different system
Webservice in first instance
A Web Mail, if the webservice is not achievable
File system if Web mail is not achievable too
If you only need to pull some data in a simple way and push it onwards to a REST service this does not "justify" the use of Spring Integration. A simple Spring (Boot) application combined with a scheduler will be sufficient.
But if you want to use a more complex data source for which an endpoint is available, you need transformations, complex and flexible routing is a high priority or even Enterprise Integration Patterns (EIP) then Spring Integration is for you. Have a look at the Overview and decide if it mentions something you consider as valuable to you.
Perhaps you will create additional value by mixing in Spring Batch if you need to process a lot of data.
But as I understand your current demand starting with just a RESTTemplate should do for the moment. Starting small will not prevent you from switching to Spring Integration later on.
Have a look at the various tutorials and guides provided by the Spring Boot project. There is even an example for Spring Integration.