[wp-trac] [WordPress Trac] #47292: Heartbeat API cause Apache/PHP to exhaust memory

[WordPress Trac]

#47292: Heartbeat API cause Apache/PHP to exhaust memory
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 Reporter:  mailandguardian  |      Owner:  (none)
     Type:  defect (bug)     |     Status:  new
 Priority:  normal           |  Milestone:  Awaiting Review
Component:  General          |    Version:  5.2
 Severity:  critical         |   Keywords:  needs-patch
  Focuses:                   |
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 WordPress 5.2
 Apache/2.4 MPM Prefork (Debian9)
 PHP 7.0  Also tried upgrading to PHP 7.2

 What you expected to happen:
 Apache memory footprint should remain stable.

 Steps to reproduce:
 Install click-to-deploy-images-wordpress-ha from Google Marketplace.
 Upgrade to WordPress 5.2
 Import and edit some posts in WordPress Admin
 Observe Client side: Examine headers in Chrome Console specifically /wp-
 admin/admin-ajax.php
 Observe Server side on Admin VM : Monitor apache memory with: free -m or
 htop

 Tried:
 Upgrading to PHP 7.2.
 Tweaks in wp-config.php
 define( 'AUTOSAVE_INTERVAL', 600 );
 define( 'WP_POST_REVISIONS', false );
 define( 'MEDIA_TRASH', true );
 define( 'DISABLE_WP_CRON', true );
 define( 'WP_MEMORY_LIMIT', '256M' );

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Ticket URL: <https://core.trac.wordpress.org/ticket/47292>
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