To avoid having to either hard-code or manually configure service addresses (possibly several dozen), and to reduce the project's dependency on docker to deal with routing and discovery, the option to use [Zookeeper](https://zookeeper.apache.org/) to manage services and discovery has been added.
A service registry interface was added, with a Zookeeper implementation and a basic implementation that only works on docker and hard-codes everything.
The last remaining REST service, the assistant-service, has been migrated to gRPC.
This also proved a good time to clear out primordial technical debt from the root of the codebase. The 'service-client' library has been taken behind the barn and given a last farewell. It's replaced by a small library for managing gRPC channels.
Since it's no longer used by anything, RxJava has been removed as a dependency from the project.
Although the current state seems reasonably stable, this is a work-in-progress commit.
We do both ip2location and ASN data.
The change also adds some keywords based on autonomous system information, on a somewhat experimental basis. It would be neat to be able to e.g. exclude cloud services or just e.g. cloudflare from the search results.
This commit also fixes a bug in the loader where the IP field wouldn't always populate as intended, and refactors the DomainInformationService to use significantly fewer SQL queries.
This reduces the impact of restarting the search service, as the site information takes a few minutes to load during which it's not available. It also permits exposing this information via API in the future if there is interest in this.
The assistant service was also modified to do a late load of the suggestions trie, as this is a major contributor to its start-up time.
Finally, some changes were made to the client library, a new get() method was added that takes a TypeToken to allow deserialization of generics such as List<Foo>, and the scheduler was also modified to use virtual threads.
... also move some common configuration into the root build.gradle-file.
Support for JDK21 in lombok is a bit sketchy at the moment, but it seems to work. This upgrade is kind of important as the new index construction really benefits from Arena based lifecycle control over off-heap memory.
