reactive-spring | Project Reactor 3.3 , Spring Framework 5.2 , Spring Data

Turns out adding the filter works (s. below). I still don't fully understand how the context population of SpEL VS reactive context works in this scenario, but it works..

Does my algorithm exist in keycloak or do I have to create a custom credential algorithm ?

From the Keycloak Documentation:

Here’s an explanation of each policy type:

HashAlgorithm

Passwords are not stored as clear text. Instead they are hashed using standard hashing algorithms before they are stored or validated. The only built-in and default algorithm available is PBKDF2.

Nevertheless, Keycloak allows you to customized and deploy your own algorithm by taking advantage of Service Provider Interfaces.

1. Enable Prometheus exporter in Spring

2. Make sure metrics are scraped. You're going to watch for a threadpool_size metric. Refer your k8s/prometheus distro docs to get prometheus service discovery working for you.

3. Write a horizontal pod autoscaler (HPA) based on a Prometheus metric:

   • Setup Prometheus-Adapter and follow the HPA walkthrough.
   • Or follow this guide https://github.com/stefanprodan/k8s-prom-hpa

Depending on what k8s distro you are using, you might have different ways to get the Prometheus and prometheus discovery:

• (example platform built-in) https://cloud.google.com/stackdriver/docs/solutions/gke/prometheus
• (example product) https://docs.datadoghq.com/integrations/prometheus/
• (example opensource) https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack
• any other prometheus solution

As for the SearchHit: This class contains information form a search result that is not part of the entity, but part of the search result like score, sort values, highlight entries. If you don't need this and just want to have a Flux with the entity alone:

First of all findAll(Pageable pageable) is a method of PagingAndSortingRepository. Spring data support method query using findBy which is not related with findAll(Pageable pageable).

Currently Reactive Spring Data MongoDB don't support any mehtod like findAll(pageable: Pageable) but there is a way to do it.

I had the same problem a few months ago and wanted to share how I solved it.

Spring does not provide any out-of-the-box solution for this problem. A few months ago i created a proof of concept how to solve it and just published the example project on Github.

spring-mongodb-multi-tenancy-example

In short: I created a custom MultiTenancyReactiveMongoTemplate which internally delegates to the the actual ReactiveMongoTemplate based on the tenantId from subscriberContext. The tenantId is extracted from a http-request header in a custom WebFilter which puts it in the subscriberContext.

This workaround works for most cases and also supports auto-index creation and the use of the ReactiveMongoRepository's.

But also has some limitations as Transactions, IndexOps on the MultiTenancyReactiveMongoTemplate or the ReactiveGridFSTemplate do not work with the provided solution. Some of the things could be implemented with other delegating 'templates' but some things will never work as these operations simply return scalar values (no Publisher) and there is no way to access the subscriberContext in these cases.

If you do not need these features you could probably go with this solution.

You spin up and configure instances of the service for each tenant/customer and put a reverse proxy 'before' these services. The reverse proxy decides which service should be used to handle the request. The reverse proxy can be implemented very easy with for example Spring Cloud Gateway which allows you to easily implement predicates which decide (e. g. based on a auth token) which service should be used.

With technologies like CloudFoundry or Kubernetes it is no that hard anymore to orchestrate the deployment of these tenant specific services and this solution makes it also easy to do tenant specific monitoring, alerting or even billing.

We chose solution 2 because overall this was easier and scales better for us.

You can use getQueryParams to get N parameters as a map.

getQueryParams() returns MultiValueMap, so you can handle query params as a map.

Let me make small example like your code block.