fixes the cacheConfigRTFCollector UT (opensearch-project#713)

Signed-off-by: Atharva Sharma <[email protected]>

src/test/java/org/opensearch/performanceanalyzer/collectors/telemetry/RTFCacheConfigMetricsCollectorTests.java

@@ -6,13 +6,11 @@
 package org.opensearch.performanceanalyzer.collectors.telemetry;
 
 import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyDouble;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.Mockito.atLeastOnce;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
 import java.io.IOException;
 import org.junit.After;
@@ -24,26 +22,21 @@
 import org.opensearch.performanceanalyzer.commons.config.overrides.ConfigOverridesWrapper;
 import org.opensearch.performanceanalyzer.commons.metrics.MetricsConfiguration;
 import org.opensearch.performanceanalyzer.config.PerformanceAnalyzerController;
-import org.opensearch.telemetry.metrics.Histogram;
 import org.opensearch.telemetry.metrics.MetricsRegistry;
 import org.opensearch.test.OpenSearchSingleNodeTestCase;
 
 public class RTFCacheConfigMetricsCollectorTests extends OpenSearchSingleNodeTestCase {
     private static final String TEST_INDEX = "test";
     private RTFCacheConfigMetricsCollector rtfCacheConfigMetricsCollector;
     private static MetricsRegistry metricsRegistry;
-    private static Histogram testHistogram;
     private long startTimeInMills = 1153721339;
 
     @Before
     public void init() {
         MetricsConfiguration.CONFIG_MAP.put(
                 RTFCacheConfigMetricsCollector.class, MetricsConfiguration.cdefault);
         metricsRegistry = mock(MetricsRegistry.class);
-        testHistogram = mock(Histogram.class);
         OpenSearchResources.INSTANCE.setMetricsRegistry(metricsRegistry);
-        when(metricsRegistry.createHistogram(anyString(), anyString(), anyString()))
-                .thenReturn(testHistogram);
         IndicesService indicesService = getInstanceFromNode(IndicesService.class);
         OpenSearchResources.INSTANCE.setIndicesService(indicesService);
         ConfigOverridesWrapper mockWrapper = mock(ConfigOverridesWrapper.class);
@@ -62,6 +55,7 @@ public void tearDown() throws Exception {
     public void testCollectMetrics() throws IOException {
         createIndex(TEST_INDEX);
         rtfCacheConfigMetricsCollector.collectMetrics(startTimeInMills);
-        verify(testHistogram, atLeastOnce()).record(anyDouble(), any());
+        verify(metricsRegistry, atLeastOnce())
+                .createGauge(anyString(), anyString(), anyString(), any(), any());
     }
 }