maintenance: getLagTimes migrate to StatsFactory

Creates two metrics, one emitting milliseconds for backwards-compatibility and another emitting seconds, aligned with Prometheus' upstream recommendations. Update test. Bug: T359382 Change-Id: Id5a22937b60a209b6ba46633879551d24cf93a45
wikimedia · May 15, 2024 · 06e6bda · 06e6bda
1 parent c38486c
commit 06e6bda
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Showing 2 changed files with 37 additions and 20 deletions.
diff --git a/maintenance/getLagTimes.php b/maintenance/getLagTimes.php
@@ -40,7 +40,7 @@ public function __construct() {
  public function execute() {
  $services = $this->getServiceContainer();
  $lbFactory = $services->getDBLoadBalancerFactory();
- $stats = $services->getStatsdDataFactory();
+ $stats = $services->getStatsFactory();
  $lbsByType = [
  'main' => $lbFactory->getAllMainLBs(),
  'external' => $lbFactory->getAllExternalLBs()
@@ -71,7 +71,20 @@ public function execute() {
 
  if ( $this->hasOption( 'report' ) ) {
  $group = ( $type === 'external' ) ? 'external' : $cluster;
- $stats->gauge( "loadbalancer.lag.$group.$host", (int)( $lag * 1e3 ) );
+
+ // $lag is the lag duration in seconds
+ // emit milliseconds for backwards-compatibility
+ $stats->getGauge( 'loadbalancer_lag_milliseconds' )
+ ->setLabel( 'group', $group )
+ ->setLabel( 'host', $host )
+ ->copyToStatsdAt( "loadbalancer.lag.$group.$host" )
+ ->set( (int)( $lag * 1e3 ) );
+
+ // emit seconds also to align with Prometheus' recommendations
+ $stats->getGauge( 'loadbalancer_lag_seconds' )
+ ->setLabel( 'group', $group )
+ ->setLabel( 'host', $host )
+ ->set( (int)$lag );
  }
  }
  }

diff --git a/tests/phpunit/maintenance/GetLagTimesTest.php b/tests/phpunit/maintenance/GetLagTimesTest.php
@@ -2,9 +2,9 @@
 
 namespace MediaWiki\Tests\Maintenance;
 
-use IBufferingStatsdDataFactory;
 use Wikimedia\Rdbms\ILoadBalancer;
 use Wikimedia\Rdbms\LBFactory;
+use Wikimedia\Stats\StatsFactory;
 
 /**
  * @covers \GetLagTimes
@@ -52,7 +52,7 @@ public function testReportedOutput( $lag, $expected ) {
  $this->expectOutputRegex( $expected );
  }
 
- public function testSendsToStatsd() {
+ public function testStats() {
  $lbFactory = $this->createMock( LBFactory::class );
  $lbFactory->method( 'getAllMainLBs' )
  ->willReturn( [
@@ -65,25 +65,29 @@ public function testSendsToStatsd() {
  ] );
  $this->setService( 'DBLoadBalancerFactory', $lbFactory );
 
- // The Statsd service
- $gaugeArgs = [
- [ 'loadbalancer.lag.cluster1.localhost', 1000 ],
- [ 'loadbalancer.lag.cluster2.localhost', 0 ],
- [ 'loadbalancer.lag.external.localhost', 14000 ],
- ];
- $stats = $this->createMock( IBufferingStatsdDataFactory::class );
- $stats->expects( $this->exactly( 3 ) )
- ->method( 'gauge' )
- ->willReturnCallback( function ( $key, $value ) use ( &$gaugeArgs ): void {
- [ $nextKey, $nextValue ] = array_shift( $gaugeArgs );
- $this->assertSame( $nextKey, $key );
- $this->assertSame( $nextValue, $value );
- } );
-
- $this->setService( 'StatsdDataFactory', $stats );
+ $dummyGauge = StatsFactory::newNull()->getGauge( 'dummy' );
+ $sfmock = $this->createConfiguredMock( StatsFactory::class, [
+ 'getGauge' => $dummyGauge
+ ] );
+ $this->setService( 'StatsFactory', $sfmock );
 
  $this->maintenance->setOption( 'report', true );
  $this->maintenance->execute();
+
+ $expectedSamples = [
+ // milliseconds
+ [ 'cluster1.localhost', 1000.0 ],
+ [ 'cluster2.localhost', 0.0 ],
+ [ 'external.localhost', 14000.0 ],
+ // seconds
+ [ 'cluster1.localhost', 1.0 ],
+ [ 'cluster2.localhost', 0.0 ],
+ [ 'external.localhost', 14.0 ],
+ ];
+ foreach ( $dummyGauge->getSamples() as $sample ) {
+ $namespaced = implode( '.', $sample->getLabelValues() );
+ $this->assertContains( [ $namespaced, $sample->getValue() ], $expectedSamples );
+ }
  }
 
 }