Monitoring crawlers | Algolia (2024)

The Crawler offers several tools for monitoring your crawler’s performance.You can find them in the Tools section of the sidebar in the Crawler dashboard.

The Monitoring tool lets you inspect your crawled URLs by status.Select a status to review the URLs associated with that status and further details about the processed URL.

This shows the same information as the URL Inspector.

URL Inspector

The URL Inspector shows details about the latest crawl for a selected URL, such as the time it took to process the URL, links to and from this URL, or extracted records.You can search for individual URLs or filter by crawl status.

On the Inspector page, you can perform these actions with the selected URL:

• Recrawl this URL. This can be useful to check if a network error was only temporary, or if you’ve changed your crawler configuration and want to see the effect of your changes.
• Test this URL. This opens the Editor page with the URL selected in the URL Tester.

URL Tester

The URL Tester lets you test your crawler’s configuration on one URL without crawling your entire site.This is helpful when updating your crawler’s configuration or when troubleshooting issues.

To test a URL:

1. Open the Editor page in the Crawler dashboard. The URL Tester is on the right side of the screen.
2. Enter the URL you want to test. The URL tester doesn’t follow redirects: https://example.com/path/page/ isn’t the same as https://example.com/path/page, even though it might work in your browser because of redirects.
3. Click Run Test.

The results of the test are shown by category as tabs.If the test had any errors, you can use the information for troubleshooting:

Path Explorer

The Path Explorer helps you find issues when crawling your site’s different sections (paths) and URLs.It shows:

• How many URLs were crawled
• How much bandwidth was used when crawling these URLs
• How many records were extracted

The Path Explorer lets you browse your crawled site as if you’re navigating directories on your computer.Every time you select a path, all its sub-paths and their status are shown.

Data Analysis

Consistent data is essential for a great search.The data analysis tool generates a report with the number of records that have data consistency issues.For example, if some of your records miss an attribute used for ranking, or use a different data type for this attribute, these records rank lower or won’t even appear in the search results.

Find and fix bugs with the Data Analysis tool

When you have data inconsistencies, it can be difficult to track down what’s going on.The Data Analysis tool helps you find and fix the following kinds of issues:

• Missing attributes
• Empty arrays
• Attributes with different types across records
• Arrays with elements of different types, even within a single record
• Suspicious objects that could be of another type, like a string used as an object

For example, on a news website, you want to extract two fields:

• Article publication date so the most recent articles appear first.
• Recently updated status so you can promote articles with fresh information.

Start by editing the configuration to identify which selector to use to extract the publish and modified dates:

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new Crawler({ ... sitemaps: ["https://my-example-blog.com/sitemap.xml"], actions: [ { indexName: "blog", pathsToMatch: ["https://my-example-blog.com/*"], recordExtractor: function({ url, $ }) { const SEVEN_DAYS = 7 * 24 * 3600 * 1000; const title = $("h1").text(); const publishedAt = $('meta[property="article:published_time"]').attr( "content" ); const modifiedAt = $('meta[property="article:modified_time"]').attr( "content" ); let recentlyModified; if (publishedAt !== modifiedAt) { recentlyModified = new Date() - new Date(modifiedAt) < SEVEN_DAYS; } return [ { objectID: url.href, title, publishedAt, modifiedAt, recentlyModified } ]; } } ]});

Once you’ve crawled the site, use the Data Analysis tool to check for issues.In this example, you see warnings for both the date and subtitle attributes:

You have 11 records with missing data in the recentlyModified attribute.This suggests that there’s an issue with the code used to extract this piece of data.Click View URLs to investigate the warning further.

By clicking a couple of links, you notice that the publish date is always the same as the modified date.

This issue occurs when the two dates are identical.Click Test this URL to open the URL Tester.

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let recentlyModified;if (publishedAt !== modifiedAt) { recentlyModified = new Date() - new Date(modifiedAt) < SEVEN_DAYS;}

The code doesn’t set a value for the recentlyModified attribute when publishedAt is equal to modifiedAt.In this situation, it should befalse, because the article wasn’t modified.

You can update the code and immediately test the changes on the problematic URL by clicking Run Test.

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let recentlyModified = false; // set default value to `false`if (publishedAt !== modifiedAt) { recentlyModified = new Date() - new Date(modifiedAt) < SEVEN_DAYS;}

The recentlyModified attribute is now present even when an article wasn’t modified.You can now save the configuration and start a new crawl.

Once the crawl is complete, you can run another analysis to validate that the configuration is correct: it shows no warnings.