This commit includes mostly exception handling, error propagation, a few bug fixes and minor changes to log formatting. The CrawlDelayTimer, HTTP 429 responses and IOException responses are now more accurately handled.
A non-standard WarcXEntityRefused WARC record has also been introduced, essentially acting as a rejected 'response' with different semantics.
Besides these, several existing features have been refined, such as URL encoding, crawl depth incrementing and usage of Content-Length headers.
This commit further cleans up the warc->parquet conversion. It fixes issues with redirect handling in WarcRecorder, adds support information about redirects and errors due to probe failure.
It also refactors the fetch result, body extraction and content type abstractions.
This commit cleans up the warc->parquet conversion. Records with a http status other than 200 are now included.
The commit also fixes a bug where the robots.txt parser would be fed the full HTTP response (and choke), instead of the body.
The DocumentBodyExtractor code has also been cleaned up, and now offers a way of just getting the byte[] representation for later processing, as conversion to and from strings is a bit wasteful.
This commit is in a pretty rough state. It refactors the crawler fairly significantly to offer better separation of concerns. It replaces the zstd compressed json files used to store crawl data with WARC files entirely, and the converter is modified to be able to consume this data. This works, -ish.
There appears to be some bug relating to reading robots.txt, and the X-Robots-Tag header is no longer processed either.
A problem is that the WARC files are a bit too large. It will probably be likely to introduce a new format to store the crawl data long term, something like parquet; and use WARCs for intermediate storage to enable the crawler to be restarted without needing a recrawl.
At this stage, the crawler will use the WARCs to resume a crawl if it terminates incorrectly.
This is a WIP commit, since the warc files are not fully incorporated into the work flow, they are deleted after the domain is crawled.
The commit also includes fairly invasive refactoring of the crawler classes, to accomplish better separation of concerns.
In this commit, GeoIP-related classes are refactored and relocated to a common library as they are shared across multiple services.
The crawler is refactored to enable the GeoIpBlocklist to use the new GeoIpDictionary as the base of its decisions.
The converter is modified ot query this data to add a geoip:-keyword to documents to permit limiting a search to the country of the hosting server.
The commit also adds due BY-SA attribution in the search engine footer for the source of the IP geolocation data.
Partially hook in the WarcRecorder into the crawler process. So far it's not read, but should record the crawled documents.
The WarcRecorder and HttpFetcher classes were also refactored and broken apart to be easier to reason about.
This is a first step of using WARC as an intermediate flight recorder style step in the crawler, ultimately aimed at being able to resume crawls if the crawler is restarted. This component is currently not hooked into anything.
The OkHttp3 client wrapper class 'WarcRecordingFetcherClient' was implemented for web archiving. This allows for the recording of HTTP requests and responses. New classes were introduced, 'WarcDigestBuilder', 'IpInterceptingNetworkInterceptor', and 'WarcProtocolReconstructor'.
The JWarc dependency was added to the build.gradle file, and relevant unit tests were also introduced. Some HttpFetcher-adjacent structural changes were also done for better organization.
This functionality needs to be accessed by the WarcSideloader, which is in the converter. The resultant microlibrary is tiny, but I think in this case it's justifiable.
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 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.
