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.
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 production configuration assumes all content of interest is 7 bit ASCII, and makes a series of optimizations based on this. This assumption holds poorly in the wild.
Adding an **experimental** system property 'system.noFlattenUnicode', that when set to TRUE, will disable this behavior.
IMPORTANT!! The index needs to be re-constructed when this flag is changed, as different hash functions are selected for the keyword->identifier mappings.
Previously, in order to load encyclopedia data into the search engine, it was necessary to use the encyclopedia.marginalia.nu converter to first create a .db-file. This isn't very ergonomic, so parts of that code-base was lifted in as a 3rd party library, and conversion from .zim to .db is now done automatically.
The output file name is based on the original filename, plus a crc32 hash and a .db-ending, to ensure we can recycle the data on repeat loads.
Use a system.properties file to configure the system. This is loaded statically by MainClass or ProcessMainClass. Update the property names to be more consistent, and update the documentations to reflect the changes.
Several tests were manually running migrations in a large copy-paste blob of code. This makes the test less useful as it's possible to break the code while keeping the tests green by introducing a new migration that never gets run in the tests, and it's also difficult to reason about what the tests are doing.
A new test helper library is introduced with a TestMigrationLoader that can both run Flyway migrations, or load specific migrations in the cases a specific set of migrations need to be loaded. Existing tests are migrated to use the new code.
The changeset also makes the control service responsible for flyway migrations. This helps reduce the number of places the database configuration needs to be spread out. These automatic migrations can be disabled with -DdisableFlyway=true.
The commit also adds curl to the docker container, to enable docker health checks and interdependencies.
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.
Initialization parameters in DomainLoaderService and DomainIdRegistry have been updated to improve performance. This is done by adding sane default sizes to the hash tables involved, reducing GC churn, but also by setting a sensible fetch size to the queries used, and not fetching irrelevant information such as the domain name.
This variable had a very confusing name, and was dangerously easy to use in the wrong place with the result of getting something that only works as expected half the time.
Ideally this class needs an overhaul, the assumptions it makes about domain names aren't great.
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.
The repartition endpoint was mis-addressing its mqapi notifications, omitting the proper nodeId. In fixing this, it became apparent that having both @MqRequest and @MqNotification is a serious footgun, and the two should be unified into a single API where the caller isn't burdened with knowledge of the remote end's implementation specifics.
Wrapping these exceptions in a try-catch and logging them with slf4j will ensure they end up in the process logs.
The way it worked using the default exception handler, they'd print on console (which nothing captures!), leading to a very annoying debugging experience.
This behavior is an old vestige from the days of only having a single loader process. We'd truncate the links table because doing inserts/updates was too slow. This was also important because we had 32 bit ID, and there's a lot of links between domains to go around...
Instead we delete the rows associated with the current node with a stored procedure PURGE_LINKS_TABLE.
We also update the PRIMARY KEY to a BIGINT. We'll need to load the data in excess of billion times to hit an ID rollover, so it'll be fine.
* Encyclopedia sideloader; permit providing base URL.
* Storage base shows node id in GUI
* ProcessLivenessMonitorActor restarts automatically
* Clean-up of outbox code
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
... 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.
* Reduce memory churn in LoaderIndexJournalWriter, fix bug with keyword mappings as well
* Remove remains of OldDomains
* Ensure LOADER_PROCESS_OPTS gets fed to the processes
* LinkdbStatusWriter won't execute batch after each added item post 100 items
This is a system-wide change. The index used to have a lexicon, mapping words to wordIds using a large in-memory hash table. This made index-construction easier, but it
also added a fairly significant RAM penalty to both the index service and the loader.
The new design moves to 64 bit word identifiers calculated using the murmur hash of the keyword, and an index construction based on merging smaller indices.
It also became necessary half-way through to upgrade guice as its error reporting wasn't *quite* compatible with JDK20.
This provides a much cleaner separation of concerns, and makes it possible to get rid of a lot of the gunkier parts of the index service. It will also permit lowering the Xmx on the index service a fair bit, so we can get CompressedOOps again :D
