Crawler Inspector

1. Shard Calculation

Query:

Response:

Calculated Shard: 40 (from laksa053)

2. Crawled Status Check

Query:

curl -X POST \
  'http://laksa040.int.ahrefs:8124/' \
  -H 'Content-Type: text/plain' \
  -H 'X-ClickHouse-Database: crawler3' \
  -H 'Authorization: Basic YXBpOg==' \
  -d 'SELECT getAhrefsURLFromUnparsed(src_unparsed) AS found_url, ifNull(toUnixTimestamp(download_stamp), 0) AS crawl_time, ifNull(toUnixTimestamp(props_url_first_seen), 0) AS first_indexed_time, download_http_code AS http_code, src_unparsed AS src_unparsed, src_root_hash AS src_root_hash, history_drop_reason AS history_drop_reason, meta_title AS meta_title, meta_descriptions AS meta_descriptions, meta_canonical AS meta_canonical, ml_categories_json AS ml_categories_json, ml_types_json AS ml_types_json, ml_intent_types_json AS ml_intent_types_json, meta_language AS meta_language, attrs_author AS attrs_author, ifNull(toUnixTimestamp(attrs_publish_time), 0) AS attrs_publish_time, ifNull(toUnixTimestamp(attrs_original_publish_time), 0) AS attrs_original_publish_time, ifNull(attrs_is_republished, 0) AS attrs_is_republished, ifNull(attrs_nr_words, 0) AS attrs_nr_words, ifNull(attrs_boilerpipe_nr_words, 0) AS attrs_boilerpipe_nr_words, ifNull(body_ext_links_number, 0) AS body_ext_links_number, ifNull(body_int_links_number, 0) AS body_int_links_number, ifNull(meta_nofollow, 0) AS meta_nofollow, ifNull(meta_noarchive, 0) AS meta_noarchive, ifNull(props_was_rendered, 0) AS props_was_rendered, ifNull(src_redirect, \'\') AS src_redirect, ifNull(download_time_msec, 0) AS download_time_msec, ifNull(download_ttfb_msec, 0) AS download_ttfb_msec, ifNull(download_size, 0) AS download_size FROM crawler3.page_info_local FINAL PREWHERE int_partition_id = 37 AND (src_root_hash, src_unparsed) IN ((getAhrefsRootHashFromUnparsed(getAhrefsUnparsedNoserviceFromURL(\'https://www.cs.bu.edu/fac/snyder/cs132-book/L16Eigenvectors.html\')), getAhrefsUnparsedNoserviceFromURL(\'https://www.cs.bu.edu/fac/snyder/cs132-book/L16Eigenvectors.html\'))) FORMAT JSONEachRow'

Filter	Status	Condition	Details
HTTP status	PASS	`download_http_code = 200`	HTTP 200
Age cutoff	PASS	`download_stamp > now() - 6 MONTH`	1.7 months ago
History drop	PASS	`isNull(history_drop_reason)`	No drop reason
Spam/ban	PASS	`fh_dont_index != 1 AND ml_spam_score = 0`	ml_spam_score=0
Canonical	PASS	`meta_canonical IS NULL OR = '' OR = src_unparsed`	Not set

Property	Value
URL	https://www.cs.bu.edu/fac/snyder/cs132-book/L16Eigenvectors.html
Last Crawled	2026-04-14 09:53:06 (1 month ago)
First Indexed	not set
HTTP Status Code	200
Content
Meta Title	Eigenvectors and Eigenvalues — Linear Algebra, Geometry, and Computation
Meta Description	null
Meta Canonical	null
Boilerpipe Text	heavy column, fetched on demand
Markdown	heavy column, fetched on demand
Readable Markdown	heavy column, fetched on demand
ML Classification
ML Categories	null
ML Page Types	null
ML Intent Types	null
Content Metadata
Language	null
Author	null
Publish Time	not set
Original Publish Time	not set
Republished	No
Word Count (Total)	3,974
Word Count (Content)	3,763
Links
External Links	5
Internal Links	28
Technical SEO
Meta Nofollow	No
Meta Noarchive	No
JS Rendered	No
Redirect Target	null
Performance
Download Time (ms)	91
TTFB (ms)	51
Download Size (bytes)	95,708
Location
Host ID	40 (laksa040)
Partition ID	37
Root Hash	13121796707767007440
Unparsed URL	edu,bu!cs,www,/fac/snyder/cs132-book/L16Eigenvectors.html s443

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1. Shard Calculation

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2. Crawled Status Check

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3. Robots.txt Check

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4. Spam/Ban Check

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5. Seen Status Check

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