Changeset 8897

Timestamp:

05/30/2019 07:04:41 AM (6 years ago)

Author:

dd32

Message:

Plugin Directory: Search: Include some debug info in the search stampede code to isolate some cache bugs.

File:

• sites/trunk/wordpress.org/public_html/wp-content/plugins/plugin-directory/libs/site-search/jetpack-search.php (modified) (3 diffs)

sites/trunk/wordpress.org/public_html/wp-content/plugins/plugin-directory/libs/site-search/jetpack-search.php

@@ -226 +226 @@
         $cache_key    = md5( $json_es_args );
         $lock_key     = 'lock-' . $cache_key;
+        $count_key    = 'count-' . $cache_key;
 
         $response = wp_cache_get( $cache_key, self::CACHE_GROUP );
@@ -232 +233 @@
         // Other processes will use the stale cached value if it's present, even for a while after the expiration time if a fresh value is still being fetched.
         if ( wp_cache_add( $lock_key, 1, self::CACHE_GROUP, 15 ) ) {
+            // Keep track of the number of concurrent requests for this key
+            wp_cache_set( $count_key, 1, self::CACHE_GROUP, 60 );
 
             // If the error volume is high, there's a proportionally lower chance that we'll actually attempt to hit the API.
@@ -297 +300 @@
             // Stampede protection has kicked in, AND we have no stale cached value to display. That's bad - possibly indicates cache exhaustion
             if ( false === $response ) {
-                trigger_error( 'Plugin directory search: no cached results available during stampede.', E_USER_WARNING );
+                // Keep a track of how many cache stampede's happen per minute.
+                wp_cache_incr( 'search-stampede-failures', 1, self::CACHE_GROUP ) || wp_cache_set( 'search-stampede-failures', 1, self::CACHE_GROUP, 60 );
+
+                // Include the number of times this branch has been hit
+                $request_count = wp_cache_incr( $count_key, 1, self::CACHE_GROUP );
+                trigger_error( 'Plugin directory search: no cached results available during stampede. Requests: ' . $request_count, E_USER_WARNING );
             }
         }