Default number of threads in Spring boot 2.0 reactive webflux configuration - spring

While using Spring 5 reactive webflux with Spring boot 2.0, what's the default number of threads used to handle requests? How can I configure the number of threads used?

The default number of threads for request handling is determined by the underlying web server; by default, Spring Boot 2.0 is using Reactor Netty, which is using Netty's defaults (check out the EventLoopGroup documentation for that).
Spring Boot will soon allow you to customize that part (see #10418). In the meantime, you can provide your own ReactiveWebServerFactory bean and change that through the HttpServer configuration options (see this comment).

Currently, it seems that Spring Webflux 2.0 does not provide the ability to control threads.
Spring Webflux 2.0 is using Reactor-Netty. And ReactorNettyclass provides some configurations.
reactor.netty.ioWorkerCount
reactor.netty.ioSelectCount
reactor.netty.pool.maxConnections
etc
So, You can use it like this.
System.setProperty("reactor.netty.ioWorkerCount", "100");
I hope that Spring Boot will provide a custom configuration.

Related

Control migration of a spring jersey app to webflux through a feature flag

We are thinking of how to migrate spring jersey app to webflux gradually, by converting jersey services to webflux controllers, and converting jersey filters to webfilters one by one, controlled by a feature flag. Since webflux can run on modern servlet containers, I am thinking of mapping the original path to a servlet that just does the forwarding based on the value of the feature flag. However, as I understand, spring boot does not allow webflux to co-exist with spring MVC/Jersey. What's a best way to migrate existing app to webflux?

Spring boot reactive (webflux) support with #EnableResourceServer

I am trying to migrate my existing spring boot 1.5 resource server (oauth2) to spring boot 2.x, while do so i am facing difficulties in providing reactive support for the same. It looks like i can not use reactive webflux when i use pring-cloud-starter-oauth2, i have few questions:
does spring boot 2.0.3 supports webflux + oauth2 resource servers using #EnableResourceServer, is yes then what is right way to implement it?
If it does not support, what are other possible options? Spring 5 security documentations says that it does not support authorization server and resource server at this moment.
Thank you in advance
Short answer: no.
There's no support to implement your own Authorization nor Resource server using webflux.

Metrics of redis and solr in spring boot

I have services built in spring boot 2.0.2. I`m using redis and solrj.
Now if i want to get metrics of redis and solr. It don`t show in
http://localhost:8080/actuator/metrics
Is there any way e.g making custom endpoint to get redis and solr metrics?
Any help would be appreciated..
Yes, it should be possible.
Spring boot 2's default metrics framework is Micrometer
When this framework is integrated into spring boot application (via starter as usual), any metrics reported to micrometer will immediately appear in spring boot actuator.
So the question is whether the redis/solrj integration expose Metrics or not.
If they are not, you'll have to understand what exactly you want to measure and plug in the integration.
Here is the example:
import io.micrometer.core.annotation;
#Timed("my-redis-calls")
public void doSomethingInMyCode() {
//call redis here
}
Of course, there is also a programmatic interface, using annotations in not mandatory
The code shown in Mark Bramnik's answer doesn't specifically give you timing for Redis client calls, it gives you timing for doSomethingInMyCode method, which can be different.
Micrometer support seems to be available in the Lettuce 6.1 release.
MeterRegistry meterRegistry = …;
MicrometerOptions options = MicrometerOptions.create();
ClientResources resources = ClientResources.builder().commandLatencyRecorder(new MicrometerCommandLatencyRecorder(meterRegistry, options)).build();
RedisClient client = RedisClient.create(resources);
https://lettuce.io/core/release/reference/index.html#command.latency.metrics.micrometer

Spring mvc and webflux in 1 spring boot application

I got below instruction from spring boot doc:
Adding both spring-boot-starter-web and spring-boot-starter-webflux modules in your application results in Spring Boot auto-configuring Spring MVC, not WebFlux. This behavior has been chosen because many Spring developers add spring-boot-starter-webflux to their Spring MVC application to use the reactive WebClient. You can still enforce your choice by setting the chosen application type to SpringApplication.setWebApplicationType(WebApplicationType.REACTIVE)
My question is:
What if my application contains both MVC services and webflux services?
Is it supported?
For example:
I may have some existing admin service which is MVC based. Now I want to add some new services with webflux style.
No, this is not supported. Spring MVC and Spring WebFlux have different runtime models and don't support the same servers (for example, Spring WebFlux can be run with Netty, Spring MVC cannot).
Also, Spring MVC and Spring WebFlux are full web frameworks, meaning each has its own infrastructure that somehow duplicates the other. Deploying both in the same app would make it difficult to map requests (which requests should go where?).

Implement Spring Cloud Sleuth's TracingWebFillter in Spring WebFlux

I have a Spring Boot Reactive application using Functional Endpoints ( Kotlin) that uses Spring Cloud Sleuth. I want to customize the response headers to include the trace id. I looked at the manual and saw the section on using the TraceFilter : 1
I tried to do the same using a TraceWebFilter, but it doesn't expose the constructors. Is there a way to implement this customization when using the Reactive Web Framework.
I am using version 2.0.0.M5 for Spring Cloud Sleuth
Thanks in advance!
Please check out the latest master - we've migrated to Brave. You can write your WebFilter that will delegate to TraceWebFilter. Or you can just copy our TraceWebFilter and alter it in the way you need to.

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