dcb43a3308
The most common error when dealing with Slop columns is that they can fall out of sync with each other if the programmer accidentally does a conditional read and forgets to skip. The second most common error is forgetting to close one of the columns in a reader or writer. To deal with both cases, a new class SlopTable is added that keeps track of the lifecycle of all slop columns and performs a check when closing them that they are in sync. |
||
|---|---|---|
| .. | ||
| converting-process | ||
| crawling-process | ||
| index-constructor-process | ||
| loading-process | ||
| process-mq-api | ||
| 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 |
+------------+