785d8deadd
Wrote a new test to examine the redirect behavior of the crawler, ensuring that the redirect URL is the URL that is reported in the parquet file. This works as intended. Noticed in the course of this that the crawler doesn't add links from meta-tag redirects to the crawl frontier. Added logic to handle this case, amended the test case to verify the new behavior. Added the meta-redirect case to the HtmlDocumentProcessorPlugin as well, so that we consider it a link between documents in the unlikely case that a meta redirect is to another domain. |
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|---|---|---|
| .. | ||
| converting-process | ||
| crawling-process | ||
| index-constructor-process | ||
| loading-process | ||
| test-data | ||
| website-adjacencies-calculator | ||
| readme.md | ||
Processes
1. Crawl Process
The crawling-process fetches website contents, temporarily saving them as WARC files, and then re-converts them into parquet models. Both are described in crawling-model.
The operation is optionally defined by a crawl specification, which can be created in the control GUI.
2. Converting Process
The converting-process reads crawl data from the crawling step and processes them, extracting keywords and metadata and saves them as parquet files described in processed-data.
3. Loading Process
The loading-process reads the processed data.
It has creates an index journal, a link database, and loads domains and domain-links into the MariaDB database.
4. Index Construction Process
The index-construction-process constructs indices from the data generated by the loader.
Overview
Schematically the crawling and loading process looks like this:
+-----------+
| CRAWLING | Fetch each URL and
| STEP | output to file
+-----------+
|
//========================\\
|| Parquet: || Crawl
|| Status, HTML[], ... || Files
|| Status, HTML[], ... ||
|| Status, HTML[], ... ||
|| ... ||
\\========================//
|
+------------+
| CONVERTING | Analyze HTML and
| STEP | extract keywords
+------------+ features, links, URLs
|
//==================\\
|| Parquet: || Processed
|| Documents[] || Files
|| Domains[] ||
|| Links[] ||
\\==================//
|
+------------+ Insert domains into mariadb
| LOADING | Insert URLs, titles in link DB
| STEP | Insert keywords in Index
+------------+
|
+------------+
| CONSTRUCT | Make the data searchable
| INDEX |
+------------+