Look, this will make the git history look funny, but trimming unnecessary depth from the source tree is a very necessary sanity-preserving measure when dealing with a super-modularized codebase like this one.
While it makes the project configuration a bit less conventional, it will save you several clicks every time you jump between modules. Which you'll do a lot, because it's *modul*ar. The src/main/java convention makes a lot of sense for a non-modular project though. This ain't that.
Cleaning out a lot of old junk from the code, and one thing lead to another...
* Build is improved, now constructing docker images with 'jib'. Clean build went from 3 minutes to 50 seconds.
* The ProcessService's spawning is smarter. Will now just spawn a java process instead of relying on the application plugin's generated outputs.
* Project is migrated to GraalVM
* gRPC clients are re-written with a neat fluent/functional style. e.g.
```channelPool.call(grpcStub::method)
.async(executor) // <-- optional
.run(argument);
```
This change is primarily to allow handling ManagedChannel errors, but it turned out to be a pretty clean API overall.
* For now the project is all in on zookeeper
* Service discovery is now based on APIs and not services. Theoretically means we could ship the same code either a monolith or a service mesh.
* To this end, began modularizing a few of the APIs so that they aren't strongly "living" in a service. WIP!
Missing is documentation and testing, and some more breaking apart of code.
The change adds a hostname validation step to remove endpoints from the ZkServiceRegistry when they do not resolve. This is a scenario that primarily happens when running in docker, and the entire system is started and stopped.
The warmup would sometimes crash during a cold start-up, because it could not get an API. Changed the warmup to just create a GrpcSingleNodeChannelPool for the node.
The query service delegates and aggregates IndexDomainLinksApiGrpc
messages to the index services. The query client was accidentally
also doing this, instead of talking to the query client.
Fixed so it correctly talks to the query client and nothing else.
Adds new ways to configure the bind and external IP addresses for a service. Notably, if the environment variable WMSA_IN_DOCKER is present, the system will grab the HOSTNAME variable and announce that as the external address in the service registry.
The default bind address is also changed to be 0.0.0.0 only if WMSA_IN_DOCKER is present, otherwise 127.0.0.1; as this is a more secure default.
The previous code made an incorrect assumption that all routes refer to the same node, and would overwrite the route list on each update. This lead to storms of closing and opening channels whenever an update was received.
The new code is correctly aware that we may talk to multiple nodes.
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.
In the scenario where an operator
* Performs a new crawl from spec
* Doesn't load the data into the index
* Recrawls the data
The recrawl will not find the domains in the database, and the crawl log will be overwritten with an empty file,
irrecoverably losing the crawl log making it impossible to load!
To mitigate the impact similar problems, the change saves a backup of the old crawl log, as well as complains about this happening.
More specifically to this exact scenario however, the parquet-loaded domains are also preemptively inserted into the domain database at the start of the crawl. This should help the DbCrawlSpecProvider to find them regardless of loaded state.
This may seem a bit redundant, but losing crawl data is arguably the worst type of disaster scenario for this software, so it's arguably merited.
To help services start faster, the blacklist will no longer block until it's loaded. If such a behavior is desirable, a method was added to explicitly wait for the data.
The domain blacklist blocked the start-up of each process that injected it, adding like 30 seconds to the start-up time in prod.
This change moves the loading to a separate thread entirely. For threads or processes that require the blacklist to be definitely loaded, a helper method was added that blocks until that time.
This filter currently does not distinguish itself very much from the unfiltered results, and lends the impression that the filters don't "do anything".
It may come back in some shape or form in the future, with some additional tweaking of the rankings...
Modified the DbCrawlSpecProvider to shuffle domains after loading to ensure a good mix for each crawl. This change prevents overload of crawling the same server in parallel from different subdomains or crawling big domains all at once.
Refactored the GRPC Stub Pool for better handling of channel SHUTDOWN state. Any disconnected channels are now re-created before returning the stub.
The class was also renamed to GrpcChannelPool, as we no longer pool the stubs.
Clean up the sideloading code a bit, making the Reddit sideloader use the more sophisticated SideloaderProcessing approach to sideloading, instead of mimicing StackexchangeSideloader's cruder approach.
The reddit sideloader now uses the SideloaderProcessing class. It also properly sets js-attributes for the sideloaded documents.
The control GUI now also filters the upload directory items based on name, and disables the items that do not have appropriate filenames.
Fix a bug where sideloading stackexchange files by explicitly selecting the 7z file would fail, since the 7z file would be passed along to the converter rather than the path to the pre-converted .db file.
