geonetwork / geonetwork-microservices

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Access indexing service using a proper web client #12

Open groldan opened 4 years ago

groldan commented 4 years ago

org.fao.geonet.searching.controller.EsHttpProxy uses manual http connection handling to query the indexing service at the URL defined by ${gn.index.url}.

In order for the app to be "cloud native", it must do so in a way that supports automatic client-side load balancing, so that the value of ${gn.index.url} can be the name of the indexing service, and the load-balanced http client can discern which service instance to hit (usually it has a cache of service instances retrieved from discovery-service).

The easiest way of achieving so is using spring's WebClient (see https://spring.io/guides/gs/spring-cloud-loadbalancer/) The recommended way is to create an OpenFeign client for the target service, which under the hood will use WebClient

fxprunayre commented 4 years ago

In order for the app to be "cloud native", it must do so in a way that supports automatic client-side load balancing, so that the value of ${gn.index.url} can be the name of the indexing service, and the load-balanced http client can discern which service instance to hit (usually it has a cache of service instances retrieved from discovery-service).

The search app needs only the Elasticsearch instance. For the time being we have usually only one, but the idea is to have a cluster of 3 at least.

When using Java API, you can select an array of node to connect to https://www.elastic.co/guide/en/elasticsearch/client/java-rest/7.9/java-rest-high-getting-started-initialization.html. So maybe we should have at some point similar config for the HTTP proxy? or a route which balance across nodes?

So the current situation is

And we should move to something like

So the actions would be: