[NUTCH-2690] Configurable and fast URL filter

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Implemented
• Fix Version/s: 1.16
• Component/s: plugin
• Patch Info: Patch Available
• Assignee: Sebastian Nagel
• Reporter: Sebastian Nagel
• Created: 22/Jan/19 15:48
• Updated: 28/Jan/21 13:56
• Resolved: 06/May/19 15:32

Description

This improvement introduces a new URL filter plugin "urlfilter-fast" (naming debatable) which is in use at Common Crawl since 2013 to apply a long list of filters.

1. an exact (suffix) match against the host name is done to retrieve host/domain-specific regex rules
2. applies a regular expression against the path (and query) component of the URL

What makes it faster than urlfilter-regex for common cases:

• regexes are selected by host name or it's domain suffix, so there are usually fewer rules to be checked. That's similar to NUTCH-1838 but any domain suffix can be matched including subdomain.domain.com, com or . for global rules. The selection by host name suffix is considerably fast.
• regexes are applied only to the path component (optionally including the query) and not the entire URL.
  Matching against a shorter string can make a huge difference for more complex regular expressions.
• the rule to deny everything from a host or domain gets special treatment to be fast

More details about the rule format are found in the plugin's README.

Issue Links

• links to: GitHub Pull Request #433