Since the performance fix in 3359f72239 had a huge positive impact without reducing result quality, it's possible to remove the QueryBranchWalker and associated code.
Previously, in an experimental change, only the first paragraph was indexed, intended to reduce the amount of noisy tangential hits. This was not a good idea, so the change is reverted.
This functionality fell into disrepair some while ago. It's supposed to allow non-mandatory search terms that boost the ranking if they are present in the document.
The change set cleans up the data model for the term-level data. This used to contain a bunch of fields with document-level metadata. This data-duplication means a larger memory footprint and worse memory locality.
The ranking code is also modified to not accept SearchResultKeywordScores, but rather CompiledQueryLong and CqDataInts containing only the term metadata and the frequency information needed for ranking. This is again an effort to improve memory locality.
The sign of the counter is used to indicate whether a term has appeared as title. Until it's seen in the title, it's provisionally saved as a negative count.
We no longer break the query into "sets" of search terms and need to adapt the code to not use this assumption.
For the API service, we'll simulate the old behavior to keep the API stable.
For the search service, we'll introduce a new way of calculating positions through tree aggregation.
The code would always re-initialize the static ngramLexicon and rdrposTagger fields with new instances even if they were already instantiated, leading to a ton of unnecessary RAM allocation.
The modified behavior checks for nullity before creating a new instance.
Seems to work, tests are green and initial testing finds no errors. Still a bit untested, committing WIP as-is because it would suck to lose weeks of work due to a drive failure or something.
This addresses the relatively common case where the graph consists of two segments, such as x y, z w; in this case we want an output like (x_y) (z w | z_w) | x y (z_w). The generated output does somewhat pessimize a few other cases, but this one is arguably more important.
The previous behavior would listen to too many changes, and based on zookeeper and not curator assumptions about behavior, add an additional monitor on each invocation of each monitor, (which always trigger on service state changes), leading to each monitor re-registering and effectively doubling monitors in numbers whenever a service stopped or started, which in turn meant a lot of bizarre thrashing behavior even on changes in services that don't explicitly talk to each other.
This re-registering behavior is no longer done.
Netty and GRPC by default spawns an incredible number of threads on high-core CPUs, which amount to a fair bit of RAM usage.
Add custom executors that throttle this behavior.
Add the ability to indicate to the search service that a request is malicious, and to poison the results by providing randomly reorered old results instead.
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.
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 set updates the query APIs to enable the search service to add additional criteria, such as QueryStrategy and TemporalBias.
The QueryStrategy makes it possible to e.g. require a match is in the title of a result, and TemporalBias enables penalizing results that are not within a particular time period.
These options are added to the search interface. The old 'recent results' is modified to use TemporalBias, and a new filter 'Search In Title' is added as well.
The vintage filter is modified to add a temporal bias for the past.
(converter) Loader for reddit data
Adds experimental sideloading support for pusshift.io style reddit data. This dataset is limited to data older than 2023, due to licensing changes making large-scale data extraction difficult.
Since the median post quality on reddit is not very good, he sideloader will only load a subset of self-texts and top-level comments that have sufficiently many upvotes. Empirically this appears to mostly return good matches, even if it probably could index more.
Tests were written for this, but all require local reddit data which can't be distributed with the source code. If these can not be found, the tests will shortcircuit as OK. They're mostly there for debugging, and it's fine if they don't always run.
The change also refactors the sideloading a bit since it was a bit messy, and improves the sideload UX a tiny bit.
Improve the UX of the sideload GUI by sorting the results in a sensible fashion, first by whether it's a directory, then by its filename.
The change also changes the timestamp rendering to a more human-readable format than full ISO-8601.
The sideload forms didn't properly set the label 'for' property, meaning that while label tags existed, they weren't appropriately clickable.
Also removed unnecessary limits on the sideload target being a directory for stackexchange and warc. It's been possible to directly load a particular file for a while, but not allowed due to GUI limits.
Adds experimental sideloading support for pusshift.io style reddit data. This dataset is limited to data older than 2023, due to licensing changes making large-scale data extraction difficult.
Since the median post quality on reddit is not very good, he sideloader will only load a subset of self-texts and top-level comments that have sufficiently many upvotes. Empirically this appears to mostly return good matches, even if it probably could index more.
Tests were written for this, but all require local reddit data which can't be distributed with the source code. If these can not be found, the tests will shortcircuit as OK. They're mostly there for debugging, and it's fine if they don't always run.
The change also refactors the sideloading a bit since it was a bit messy.
Look at whether the property 'system.conserveProperty' is enabled when deciding he default pool size for the converter.
If true, a much more conservative default is used, limiting the risk of running out of memory.
Adds experimental support for clustering search results by e.g. domain. At a first stage, this is only enabled for the wiki and forum filters.
The commit also cleans up the UrlDetails class, which contained a number of vestigial entries.
The WARC specification says the records should transparently remove compression. This was not done, leading to the WARC typically being a bit of a gzip-Matryoshka.
The WARC specification says the records should transparently remove compression. This was not done, leading to the WARC typically being a bit of a gzip-Matryoshka.
Recent changes to the result ranking mean the no filter mode returns sufficiently good results for most queries that filtering by default just makes the search results more restricted.
