Garbage collection time window for URL Metrics posts could be increased and made customizable

[westonruter]

When considering that a URL Metric can have an indefinite freshness TTL (#1940), where freshness then depends exclusively on the ETag, I think we should consider increasing the garbage collection time window to be greater than 1 month for od_url_metrics posts that haven't been updated:

performance/plugins/optimization-detective/storage/class-od-url-metrics-post-type.php

Lines 295 to 319 in 69b7a14

	/**
	* Deletes posts that have not been modified in the past month.
	*
	* @since 0.1.0
	*/
	public static function delete_stale_posts(): void {
	$one_month_ago = gmdate( 'Y-m-d H:i:s', strtotime( '-1 month' ) );
	$query = new WP_Query(
	array(
	'post_type' => self::SLUG,
	'posts_per_page' => 100,
	'date_query' => array(
	'column' => 'post_modified_gmt',
	'before' => $one_month_ago,
	),
	)
	);
	foreach ( $query->posts as $post ) {
	if ( $post instanceof WP_Post && self::SLUG === $post->post_type ) { // Sanity check.
	wp_delete_post( $post->ID, true );
	}
	}
	}

Consider sites that get very little traffic. Just because a page doesn't get visited once a month shouldn't result in the URL Metrics being purged. Maybe something like 3 months or 6 months would be more reasonable for the long tail of sites without much traffic.

The garbage collection TTL should probably have a filter to allow it to be customized (or disabled).

Note that if someone deletes a post there is no logic to attempt to delete any corresponding od_url_metrics posts, since there is no connection between the two. I don't think this is necessarily needed.

Docs will also need to be updated here:

performance/plugins/optimization-detective/docs/introduction.md

Line 189 in 69b7a14

When an `od_url_metrics` post has not been updated in a month then it is garbage-collected, since it is likely the original URL has gone away.

[hbhalodia]

Hi @westonruter, I would like to pick this issue.

Just wanted some clarification, as suggested should we add the filter or provide some settings in the plugin, where we can set the time in months and just use that settings would be more customizable?

[westonruter]

@hbhalodia The filter can be for the number of seconds, so it can default to something like 6 * MONTH_IN_SECONDS. ANd yes, it would be a filter, no settings UI.