Track metrics related to dblist generation

extension.json

@@ -416,6 +416,10 @@
 			"description": "String. The main part of subdomains, e.g. wiki.example.org, example.org is the main part.",
 			"value": ""
 		},
+		"CreateWikiTrackDatabaseListMetrics": {
+			"description": "Boolean. Whether to track metrics related to the (re)generation of database lists.",
+			"value": false
+		},
 		"CreateWikiUseClosedWikis": {
 			"description": "Boolean. Whether to implement front end logic for closing wikis.",
 			"value": false

includes/ConfigNames.php

@@ -35,6 +35,8 @@ class ConfigNames {
 
 	public const EmailNotifications = 'CreateWikiEmailNotifications';
 
+	public const TrackDatabaseListMetrics = 'CreateWikiTrackDatabaseListMetrics';
+
 	public const EnableManageInactiveWikis = 'CreateWikiEnableManageInactiveWikis';
 
 	public const EnableRESTAPI = 'CreateWikiEnableRESTAPI';

includes/Helpers/RemoteWiki.php

@@ -470,7 +470,7 @@ public function commit(): void {
 			}
 
 			if ( $this->resetDatabaseLists ) {
-				$this->dataStore->resetDatabaseLists( isNewChanges: true );
+				$this->dataStore->resetDatabaseLists( isNewChanges: true, caller: __METHOD__ );
 			}
 
 			$this->hookRunner->onCreateWikiRemoteWikiCommit( $this->dbname );

includes/ServiceWiring.php

@@ -34,6 +34,7 @@
 	'CreateWikiDataStore' => static function ( MediaWikiServices $services ): CreateWikiDataStore {
 		return new CreateWikiDataStore(
 			$services->getObjectCacheFactory(),
+			$services->getStatsFactory(),
 			$services->get( 'CreateWikiDatabaseUtils' ),
 			$services->get( 'CreateWikiHookRunner' ),
 			new ServiceOptions(

includes/Services/CreateWikiDataStore.php

@@ -12,6 +12,7 @@
 use Wikimedia\ObjectCache\BagOStuff;
 use Wikimedia\Rdbms\IReadableDatabase;
 use Wikimedia\StaticArrayWriter;
+use Wikimedia\Stats\StatsFactory;
 use function array_keys;
 use function file_put_contents;
 use function function_exists;
@@ -28,6 +29,7 @@ class CreateWikiDataStore {
 	public const CONSTRUCTOR_OPTIONS = [
 		ConfigNames::CacheDirectory,
 		ConfigNames::CacheType,
+		ConfigNames::TrackDatabaseListMetrics,
 		MainConfigNames::CacheDirectory,
 		MainConfigNames::LocalDatabases,
 	];
@@ -41,9 +43,11 @@ class CreateWikiDataStore {
 	private readonly string $cacheDir;
 	private int $timestamp;
 	private int $localServerTimestamp;
+	private readonly bool $trackDatabaseListMetrics;
 
 	public function __construct(
 		ObjectCacheFactory $objectCacheFactory,
+		private readonly StatsFactory $statsFactory,
 		private readonly CreateWikiDatabaseUtils $databaseUtils,
 		private readonly CreateWikiHookRunner $hookRunner,
 		private readonly ServiceOptions $options
@@ -64,6 +68,8 @@ public function __construct(
 		$this->localServerTimestamp = (int)$this->localServerCache->get(
 			$this->localServerCache->makeGlobalKey( self::CACHE_KEY, 'databases-local' )
 		);
+
+		$this->trackDatabaseListMetrics = $this->options->get( ConfigNames::TrackDatabaseListMetrics );
 	}
 
 	/**
@@ -73,7 +79,7 @@ public function __construct(
 	 */
 	public function syncCache(): void {
 		if ( !$this->timestamp ) {
-			$this->resetDatabaseLists( isNewChanges: true );
+			$this->resetDatabaseLists( isNewChanges: true, caller: __METHOD__ );
 			return;
 		}
 
@@ -86,7 +92,7 @@ public function syncCache(): void {
 		// Only regenerate if localServerTimestamp is smaller than timestamp so multiple processes on the
 		// same server don't try regenerating the dblists at the same time.
 		if ( ( $mtime === 0 || $mtime < $this->timestamp ) && $this->localServerTimestamp < $this->timestamp ) {
-			$this->resetDatabaseLists( isNewChanges: false );
+			$this->resetDatabaseLists( isNewChanges: false, caller: __METHOD__ );
 		}
 	}
 
@@ -105,7 +111,20 @@ public function getAllDatabases(): array {
 	 * the updated list to a PHP file within the cache directory. It also updates the
 	 * modification time (mtime) and stores it in the cache for future reference.
 	 */
-	public function resetDatabaseLists( bool $isNewChanges ): void {
+	// @phan-suppress-next-line PhanDisallowedOptionalMethodParameter
+	public function resetDatabaseLists( bool $isNewChanges, ?string $caller = null ): void {
+		$timer = null;
+		if ( $this->trackDatabaseListMetrics ) {
+			/** @phan-suppress-next-line PhanPossiblyUndeclaredMethod */
+			$this->statsFactory->getCounter( 'createwiki_dblist_generation_total' )
+				->setLabel( 'cause', $caller ?? 'unknown' )
+				->setLabel( 'new_changes', $isNewChanges ? 'Yes' : 'No' )
+				->increment();
+
+			$timer = $this->statsFactory->getTiming( 'createwiki_dblist_generation_seconds' )
+				->start();
+		}
+
 		$mtime = time();
 		$this->localServerCache->set(
 			$this->localServerCache->makeGlobalKey( self::CACHE_KEY, 'databases-local' ),
@@ -132,6 +151,7 @@ public function resetDatabaseLists( bool $isNewChanges ): void {
 				$this->writeToFile( $name, $list );
 			}
 
+			$timer?->stop();
 			return;
 		}
 
@@ -171,6 +191,7 @@ public function resetDatabaseLists( bool $isNewChanges ): void {
 		];
 
 		$this->writeToFile( 'databases', $list );
+		$timer?->stop();
 	}
 
 	/**

includes/Services/WikiManagerFactory.php

@@ -266,9 +266,10 @@ private function doAfterCreate(
 
 		$this->hookRunner->onCreateWikiCreation( $this->dbname, $private );
 
+		$method = __METHOD__;
 		DeferredUpdates::addCallableUpdate(
-			function () use ( $requester, $extra ) {
-				$this->dataStore->resetDatabaseLists( isNewChanges: true );
+			function () use ( $requester, $extra, $method ) {
+				$this->dataStore->resetDatabaseLists( isNewChanges: true, caller: $method );
 				$limits = [ 'memory' => 0, 'filesize' => 0, 'time' => 0, 'walltime' => 0 ];
 
 				Shell::makeScriptCommand(
@@ -383,7 +384,7 @@ public function delete( bool $force ): ?string {
 				->execute();
 		}
 
-		$this->dataStore->resetDatabaseLists( isNewChanges: true );
+		$this->dataStore->resetDatabaseLists( isNewChanges: true, caller: __METHOD__ );
 		$this->hookRunner->onCreateWikiDeletion( $this->cwdb, $this->dbname );
 
 		return null;
@@ -417,7 +418,7 @@ public function rename( string $newDatabaseName ): ?string {
 				->execute();
 		}
 
-		$this->dataStore->resetDatabaseLists( isNewChanges: true );
+		$this->dataStore->resetDatabaseLists( isNewChanges: true, caller: __METHOD__ );
 		$this->hookRunner->onCreateWikiRename( $this->cwdb, $this->dbname, $newDatabaseName );
 
 		return null;

maintenance/ManageInactiveWikis.php

@@ -77,7 +77,7 @@ public function execute(): void {
 			}
 		}
 
-		$this->dataStore->resetDatabaseLists( isNewChanges: true );
+		$this->dataStore->resetDatabaseLists( isNewChanges: true, caller: __METHOD__ );
 	}
 
 	private function checkLastActivity(