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Website Scraper Resume Scan of Unstable or Large Websites

Some webservers are sluggish or denie access to unknown crawlers like A1 Website Scraper. To ensure everything gets crawled, you can use "resume" functionality in website scraper tool.
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 To see all the options available, you will have to switch off easy mode 

 With options that use a dropdown list, any [+] or [-] button next to adds or removes items in the list itself 

Resume Scan to Fix URLs with Error Response Codes

There can be many reasons to resume a website scan after it stopped. One being webservers can overload and respond with error codes for URLs, typically
  • 503 : Service Temporarily Unavailable
  • 500 : Internal Server Error
  • -4 : CommError

An easy way to determine if any errors are left throughout entire website is to view directory summary for the root directory / domain.

website directory summary

Then use the resume functionality in A1 Website Scraper to recrawl these URLs. Continue to do so until no errors are left.

resume website scan

While the website scan is running you can at any time:
  1. Pause and stop the website scan.
  2. Resume and continue your website scan.

How to use website scan and crawl resume functionality:
  • To pause a scan is the same as to stop a scan. If scan is stopped/paused or internet disconnects, you can resume.
  • Note: You can save the project. This enables you to load the project at a later time. Then you can resume the project.
  • To resume a scan you need to press Resume button so it appears in pushed down state. Then click Start scan button.


Why Pausing Website Crawls Sometimes Remove URLs

You can force recrawl of certain URLs by changing their state flags in Website analysis before resuming website scan.

Depending on the program and version, the default behavior after a website scan finishes for whatever reason, e.g. being paused, is that all URLs that are excluded by webmaster filters such as robots.txt and output filters are removed.

Above behavior is not always wanted since it means website crawler will spend time rediscover URLs it has tested before. Instead you can do the following:
  • Disable Scan website | Crawler options | Apply "webmaster" and "output filters" after website scan stops.

When filtered/excluded URLs are not removed in the website scan results, you can view their state flags:

resume crawl filter flags


Resume Website Scan Analyzes URLs Again

The way the website crawl works internally, we have:
  • Found URLs: These are URLs that have been resolved and tested.
  • Analyzed content URLs: The content of these URLs (pages) have been analyzed.
  • Analyzed references URLs: The links found in content of these URLs (pages) have been resolved.

This means that all pages where all links have not been resolved will need to be analyzed again when resuming scan. To avoid this problem the website crawler can use HEAD requests to quickly resolve links to verified URLs. While this causes some extra requests during crawl to server (albeit all light), it will minimize waste to almost zero when using resume functionality.

To configure this, disable: Scan website > Crawler engine > Default to GET for page requests


Force Recrawl of Certain URLs

If you do not want to recrawl the ensite website, but Resume is not applicable because all URLs have been analyzed, you can do the following:
  • To the left where all URLs are listed, select those you want recrawled.
  • In Crawler State Flags uncheck all the Analysis xxx flags except Analysis required.
  • Click the Save button in the Crawler State Flags area.
  • In Scan website check Resume (full).
  • Start the scan.


Find More URLs in Website Scans

If you have trouble getting all URLs included in website crawls, it is important to first follow above recommendation. The reason is that URLs with error response codes are not crawled for links. By solving that problem, you will usually also end up with more URLs.

You can find more suggestions and tips in our website crawl help article.


Resume Full Versus Resume Fix Errors Versus Recrawl

  • Resume (full):
    • Keeps all URLs from earlier scan.
    • Will crawl and analyze all URLs that are not flagged as fully analyzed.
    • If any new URLs are found, these will be crawled as well.
  • Resume (fix errors):
    • Keeps all URLs from earlier scan.
    • Will test all URLs that somehow error responded during crawl.
  • Recrawl (also called Refresh):
    • Keeps all URLs from earlier scan.
    • Will crawl and analyze all URLs. This includes URLs that do not include analysis required in their crawl state flags.
      In the future, it is possible that the recrawl will prioritize URLs based on e.g. importance, when last checked, how often page changes etc.
    • If any new URLs are found, these will be crawled as well.
    • Useful in cases where you have locked content, e.g. page title for a specific URL, and want to make sure the locked data is kept.
      Use the Lock buttons found next to different data such as titles.
  • Recrawl (listed only):
    • Like Recrawl, but will not analyze or include any new URLs in scan results.
This help page is maintained by

As one of the lead developers, his hands have touched most of the code in the software from Microsys.

If you email any questions, chances are that he will be the one answering them.
A1 Website ScraperAbout A1 Website Scraper

Extract data from sites into CSV files. By scraping websites, you can grab data on websites and transform it into CSV files ready to be imported anywhere, e.g. SQL databases
     
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