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.
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.
The change deprecates the 'algorithm' field from the domain ranking set configuration. Instead, the algorithm will be chosen based on whether influence domains are provided, and whether similarity data is present.
The domain ranking code was admittedly a bit of a clown fiesta; at the same time buggy, fragile and inscrutable.
Migrating over to use JGraphT to store the link graph
when doing rankings, and using their PageRank implementation. Also added a modified version that does PersonalizedPageRank.
This change splits the previous 'repartition' action into two steps, one for recalculating the domain rankings, and one for recalculating the other ranking sets. Since only the first is necessary before the index construction, the rest can be delayed until after...
To avoid issues in handling the shotgun blast of MqNotifications, Service was switched over to use a synchronous message queue instead of an asynchronous one.
The change also modifies the behavior so that only node 1 will push the changes to the EC_DOMAIN database table, to avoid unnecessary db locks and contention with the loader.
Additionally, the change fixes a bug where the index construction code wasn't actually picking up the rankings data.
Since the index construction used to be performed by the index-service, merely saving the data to memory was enough for it to be accessible within the index-construction logic, but since it's been broken out into a separate process, the new process just injected an empty DomainRankings object instead.
To fix this, DomainRankings can now be persisted to disk, and a pre-loaded version of the object is injected into the index-construction process.
IndexJournalWriterPagingImpl was modified to not page on number of entries written, but number of (equivalent uncompressed) bytes written.
Since the failure mode if too much data is written per file is quiet corruption of the index, the former behavior was extremely fragile. The new behavior should consistently ensure that the data is sufficiently small to not cause any integer rollovers.
The change in 6dcc20038c was reverted, as there is really no sane reason to have this configurable in software.
To cope with writing large files out of order, the system needs some form of strategy to avoid writing them directly to disk, as this causes insane amounts of disk thrashing. By default, the data is just buffered in RAM. This works well on a large server, but smaller systems struggle.
To help systems with small RAM process large amounts of data, the old RandomWriteFunnel is brought back if the system property 'system.conserve-memory' is set to true. RandomWriteFunnel is buffering the construction by creating a series of small files that pigeonhole the writes into rough neighborhoods, and then it goes over the files one by one to construct one area of the file at a time. This is relatively slow and uses more than twice the disk size.
A new interface RandomFileAssembler is introduced as an abstraction for this operation. A third strategy, direct mmaps, is also introduced if the file is very small (less than 1 GB). In this domain, disk thrashing is unlikely since it will comfortably fit in RAM.
Since the bleed-flags set by the anchor tags logics have been changed to Site and SiteAdjacent, give them a bit of more importance when set together with ExternalLink.
UrlDomain and UrlPath are also only more consistently only rewarded once.
This improves query times, and gets rid of exceptions in the logs when one of the index nodes doesn't have any data loaded, yet is configured to answer queries.
The EC_DOMAIN_LINK MariaDB table stores links between domains. This is problematic, as both updating and querying this table is very slow in relation to how small the data is (~10 GB). This slowness is largely caused by the database enforcing ACID guarantees we don't particularly need.
This changeset replaces the EC_DOMAIN_LINK table with a file in each index node containing 32 bit integer pairs corresponding to links between two domains. This file is loaded in memory in each node, and can be queried via the Query Service.
A migration step is needed before this file is created in each node. Until that happens, the actual data is loaded from the EC_DOMAIN_LINK table, but accessed as though it was a file.
The changeset also migrates/renames the links.db file to documents.db to avoid naming confusion between the two.
There was as bug where if the input of ResultValuator.normalize() was negative, it was truncated to zero. This meant that "bad" results always rank the same. The penalty factor "overallPart" was moved outside of the function and was re-weighted to accomplish a better normalization.
Some of the weights were also re-adjusted based on what appears to produce better results. Needs evaluation.
This is for filtering results on how many times the term appears on the domain. The intent is to be beneficial in creating e.g. a domain search feature. It's also very helpful when tracking down spammy domains.
* Added new (optional) model file in $WMSA_HOME/data/atags.parquet
* Converter gets a component for creating a projection of its domains onto the full atags parquet file
* New WordFlag ExternalLink
* These terms are also for now flagged as title words
* Fixed a bug where Title words aliased with UrlDomain words
* Fixed a bug in the encyclopedia sideloader that gave everything too high topology ranking
This was caused by a bug in the binary search algorithm causing it to sometimes return positive values when encoding a search miss.
It was also necessary to get rid of the vestiges of the old LongArray and IntArray classes to make this fix doable.
This turned out to be very difficult to do in small isolated steps.
* Design overhaul of the control gui using bootstrap
* Move the actors out of control-service into to a new executor-service, that can be run on multiple nodes
* Add node-affinity to message queue
* (index-reverse) Parallel construction of the reverse indexes.
* (array) Remove wasteful calculation of numDistinct before merging two sorted arrays.
* (index-reverse) Force changes to disk on close, reduce logging.
* (index-reverse) Clean up merging process and add back logging
* (run) Add a conservative default for INDEX_CONSTRUCTION_PROCESS_OPTS's parallelism as it eats a lot of RAM
* (index-reverse) Better logging during processing
* (array) 2GB+ compatible write() function
* (array) 2GB+ compatible write() function
* (index-reverse) We are logging like Bolsonaro and I will not have it.
* (reverse-index) Self-diagnostics
* (btree) Fix bug in btree reader to do with large data sizes
