diff --git a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollector.java b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollector.java
index 40485ac..68924e9 100644
--- a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollector.java
+++ b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollector.java
@@ -53,7 +53,7 @@
         return filteredVertexMetricNames.entrySet().stream()
                 .collect(
                         Collectors.toMap(
-                                e -> e.getKey(),
+                                Map.Entry::getKey,
                                 e ->
                                         queryAggregatedVertexMetrics(
                                                 flinkService, cr, conf, e.getKey(), e.getValue())));
@@ -94,7 +94,18 @@
                             .get();
 
             return responseBody.getMetrics().stream()
-                    .collect(Collectors.toMap(m -> metrics.get(m.getId()), m -> m));
+                    .collect(
+                            Collectors.toMap(
+                                    m -> metrics.get(m.getId()),
+                                    m -> m,
+                                    (m1, m2) ->
+                                            new AggregatedMetric(
+                                                    m1.getId() + " merged with " + m2.getId(),
+                                                    Math.min(m1.getMin(), m2.getMin()),
+                                                    Math.max(m1.getMax(), m2.getMax()),
+                                                    // Average can't be computed
+                                                    Double.NaN,
+                                                    m1.getSum() + m2.getSum())));
         }
     }
 }
diff --git a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/ScalingMetricCollector.java b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/ScalingMetricCollector.java
index cb094e7..18478a9 100644
--- a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/ScalingMetricCollector.java
+++ b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/ScalingMetricCollector.java
@@ -53,6 +53,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -371,14 +372,13 @@
             // the first record. If this is a fresh topic or no new data has been read since
             // the last checkpoint, the pendingRecords metrics won't be available. Also, legacy
             // sources do not have this metric.
-            Optional<String> pendingRecordsMetric =
-                    FlinkMetric.PENDING_RECORDS.findAny(allMetricNames);
-            pendingRecordsMetric.ifPresentOrElse(
-                    m -> filteredMetrics.put(m, FlinkMetric.PENDING_RECORDS),
-                    () ->
-                            LOG.warn(
-                                    "pendingRecords metric for {} could not be found. Either a legacy source or an idle source. Assuming no pending records.",
-                                    jobVertexID));
+            List<String> pendingRecordsMetric = FlinkMetric.PENDING_RECORDS.findAll(allMetricNames);
+            if (pendingRecordsMetric.isEmpty()) {
+                LOG.warn(
+                        "pendingRecords metric for {} could not be found. Either a legacy source or an idle source. Assuming no pending records.",
+                        jobVertexID);
+            }
+            pendingRecordsMetric.forEach(m -> filteredMetrics.put(m, FlinkMetric.PENDING_RECORDS));
             FlinkMetric.SOURCE_TASK_NUM_RECORDS_OUT_PER_SEC
                     .findAny(allMetricNames)
                     .ifPresent(
diff --git a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/metrics/FlinkMetric.java b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/metrics/FlinkMetric.java
index 76ba7a9..703e4e7 100644
--- a/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/metrics/FlinkMetric.java
+++ b/flink-kubernetes-operator-autoscaler/src/main/java/org/apache/flink/kubernetes/operator/autoscaler/metrics/FlinkMetric.java
@@ -20,8 +20,10 @@
 import org.apache.flink.runtime.rest.messages.job.metrics.AggregatedMetric;
 
 import java.util.Collection;
+import java.util.List;
 import java.util.Optional;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 
 /**
  * Enum representing the collected Flink metrics for autoscaling. The actual metric names depend on
@@ -46,4 +48,11 @@
     public Optional<String> findAny(Collection<AggregatedMetric> metrics) {
         return metrics.stream().map(AggregatedMetric::getId).filter(predicate).findAny();
     }
+
+    public List<String> findAll(Collection<AggregatedMetric> metrics) {
+        return metrics.stream()
+                .map(AggregatedMetric::getId)
+                .filter(predicate)
+                .collect(Collectors.toList());
+    }
 }
diff --git a/flink-kubernetes-operator-autoscaler/src/test/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollectorTest.java b/flink-kubernetes-operator-autoscaler/src/test/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollectorTest.java
new file mode 100644
index 0000000..04d8310
--- /dev/null
+++ b/flink-kubernetes-operator-autoscaler/src/test/java/org/apache/flink/kubernetes/operator/autoscaler/RestApiMetricsCollectorTest.java
@@ -0,0 +1,77 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.flink.kubernetes.operator.autoscaler;
+
+import org.apache.flink.api.common.JobID;
+import org.apache.flink.configuration.Configuration;
+import org.apache.flink.kubernetes.configuration.KubernetesConfigOptions;
+import org.apache.flink.kubernetes.operator.TestingFlinkService;
+import org.apache.flink.kubernetes.operator.api.FlinkDeployment;
+import org.apache.flink.kubernetes.operator.autoscaler.metrics.FlinkMetric;
+import org.apache.flink.runtime.jobgraph.JobVertexID;
+import org.apache.flink.runtime.rest.messages.job.metrics.AggregatedMetric;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Map;
+
+/** Tests for RestApiMetrisCollector. */
+public class RestApiMetricsCollectorTest {
+
+    @Test
+    public void testAggregateMultiplePendingRecordsMetricsPerSource() {
+        var collector = new RestApiMetricsCollector();
+
+        JobVertexID jobVertexID = new JobVertexID();
+        Map<String, FlinkMetric> flinkMetrics =
+                Map.of(
+                        "a.pendingRecords", FlinkMetric.PENDING_RECORDS,
+                        "b.pendingRecords", FlinkMetric.PENDING_RECORDS);
+        Map<JobVertexID, Map<String, FlinkMetric>> metrics = Map.of(jobVertexID, flinkMetrics);
+
+        FlinkDeployment cr = new FlinkDeployment();
+        cr.getStatus().getJobStatus().setJobId(new JobID().toHexString());
+
+        TestingFlinkService flinkService = new TestingFlinkService();
+        flinkService.setAggregatedMetricsResponse(
+                List.of(
+                        new AggregatedMetric(
+                                "a.pendingRecords", Double.NaN, Double.NaN, Double.NaN, 100.),
+                        new AggregatedMetric(
+                                "b.pendingRecords", Double.NaN, Double.NaN, Double.NaN, 100.),
+                        new AggregatedMetric(
+                                "c.unrelated", Double.NaN, Double.NaN, Double.NaN, 100.)));
+
+        Configuration conf = new Configuration();
+        conf.set(KubernetesConfigOptions.CLUSTER_ID, "id");
+
+        Map<JobVertexID, Map<FlinkMetric, AggregatedMetric>> jobVertexIDMapMap =
+                collector.queryAllAggregatedMetrics(cr, flinkService, conf, metrics);
+
+        System.out.println(jobVertexIDMapMap);
+
+        Assertions.assertEquals(1, jobVertexIDMapMap.size());
+        Map<FlinkMetric, AggregatedMetric> vertexMetrics = jobVertexIDMapMap.get(jobVertexID);
+        Assertions.assertNotNull(vertexMetrics);
+        AggregatedMetric pendingRecordsMetric = vertexMetrics.get(FlinkMetric.PENDING_RECORDS);
+        Assertions.assertNotNull(pendingRecordsMetric);
+        Assertions.assertEquals(pendingRecordsMetric.getSum(), 200);
+    }
+}
diff --git a/flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/TestingFlinkService.java b/flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/TestingFlinkService.java
index d6965b0..c0dc3da 100644
--- a/flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/TestingFlinkService.java
+++ b/flink-kubernetes-operator/src/test/java/org/apache/flink/kubernetes/operator/TestingFlinkService.java
@@ -60,6 +60,9 @@
 import org.apache.flink.runtime.rest.messages.DashboardConfiguration;
 import org.apache.flink.runtime.rest.messages.EmptyResponseBody;
 import org.apache.flink.runtime.rest.messages.JobsOverviewHeaders;
+import org.apache.flink.runtime.rest.messages.job.metrics.AggregatedMetric;
+import org.apache.flink.runtime.rest.messages.job.metrics.AggregatedMetricsResponseBody;
+import org.apache.flink.runtime.rest.messages.job.metrics.AggregatedSubtaskMetricsHeaders;
 import org.apache.flink.util.SerializedThrowable;
 
 import io.fabric8.kubernetes.api.model.DeletionPropagation;
@@ -75,6 +78,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -125,6 +129,9 @@
 
     private Map<String, String> metricsValues = new HashMap<>();
 
+    @Setter
+    private Collection<AggregatedMetric> aggregatedMetricsResponse = Collections.emptyList();
+
     public TestingFlinkService() {
         super(null, new FlinkConfigManager(new Configuration()));
     }
@@ -334,6 +341,8 @@
                 (messageHeaders, messageParameters, requestBody) -> {
                     if (messageHeaders instanceof JobsOverviewHeaders) {
                         return CompletableFuture.completedFuture(getMultipleJobsDetails());
+                    } else if (messageHeaders instanceof AggregatedSubtaskMetricsHeaders) {
+                        return CompletableFuture.completedFuture(getSubtaskMetrics());
                     }
                     return CompletableFuture.completedFuture(EmptyResponseBody.getInstance());
                 });
@@ -348,6 +357,10 @@
                         .collect(Collectors.toList()));
     }
 
+    private AggregatedMetricsResponseBody getSubtaskMetrics() {
+        return new AggregatedMetricsResponseBody(aggregatedMetricsResponse);
+    }
+
     private static JobDetails toJobDetails(JobStatusMessage jobStatus) {
         return new JobDetails(
                 jobStatus.getJobId(),