[improve][broker] Add topic_load_failed metric

pulsar-broker/src/main/java/org/apache/pulsar/broker/service/BrokerService.java

@@ -1226,6 +1226,10 @@ public void deleteTopicAuthenticationWithRetry(String topic, CompletableFuture<V
 
     private CompletableFuture<Optional<Topic>> createNonPersistentTopic(String topic) {
         CompletableFuture<Optional<Topic>> topicFuture = new CompletableFuture<>();
+        topicFuture.exceptionally(t -> {
+            pulsarStats.recordTopicLoadFailed();
+            return null;
+        });
         if (!pulsar.getConfiguration().isEnableNonPersistentTopics()) {
             if (log.isDebugEnabled()) {
                 log.debug("Broker is unable to load non-persistent topic {}", topic);
@@ -1618,6 +1622,11 @@ private void createPersistentTopic(final String topic, boolean createIfMissing,
         TopicName topicName = TopicName.get(topic);
         final long topicCreateTimeMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime());
 
+        topicFuture.exceptionally(t -> {
+            pulsarStats.recordTopicLoadFailed();
+            return null;
+        });
+
         if (isTransactionInternalName(topicName)) {
             String msg = String.format("Can not create transaction system topic %s", topic);
             log.warn(msg);

pulsar-broker/src/main/java/org/apache/pulsar/broker/service/PulsarStats.java

@@ -265,6 +265,10 @@ public void recordTopicLoadTimeValue(String topic, long topicLoadLatencyMs) {
         }
     }
 
+    public void recordTopicLoadFailed() {
+        brokerOperabilityMetrics.recordTopicLoadFailed();
+    }
+
     public void recordConnectionCreate() {
         brokerOperabilityMetrics.recordConnectionCreate();
     }

pulsar-broker/src/main/java/org/apache/pulsar/broker/stats/BrokerOperabilityMetrics.java

@@ -18,6 +18,7 @@
  */
 package org.apache.pulsar.broker.stats;
 
+import io.prometheus.client.Counter;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -29,6 +30,7 @@
 /**
  */
 public class BrokerOperabilityMetrics {
+    private static final Counter TOPIC_LOAD_FAILED = Counter.build("topic_load_failed", "-").register();
     private final List<Metrics> metricsList;
     private final String localCluster;
     private final DimensionStats topicLoadStats;
@@ -84,7 +86,9 @@ Map<String, String> getDimensionMap(String metricsName) {
     }
 
     Metrics getTopicLoadMetrics() {
-        return getDimensionMetrics("topic_load_times", "topic_load", topicLoadStats);
+        Metrics metrics = getDimensionMetrics("topic_load_times", "topic_load", topicLoadStats);
+        metrics.put("brk_topic_load_failed_count", TOPIC_LOAD_FAILED.get());
+        return metrics;
     }
 
     Metrics getDimensionMetrics(String metricsName, String dimensionName, DimensionStats stats) {
@@ -112,6 +116,10 @@ public void recordTopicLoadTimeValue(long topicLoadLatencyMs) {
         topicLoadStats.recordDimensionTimeValue(topicLoadLatencyMs, TimeUnit.MILLISECONDS);
     }
 
+    public void recordTopicLoadFailed() {
+        this.TOPIC_LOAD_FAILED.inc();
+    }
+
     public void recordConnectionCreate() {
         this.connectionTotalCreatedCount.increment();
         this.connectionActive.increment();

pulsar-broker/src/test/java/org/apache/pulsar/broker/service/BrokerServiceTest.java

@@ -33,6 +33,7 @@
 import com.google.gson.Gson;
 import com.google.gson.JsonArray;
 import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.EventLoopGroup;
 import io.netty.util.concurrent.DefaultThreadFactory;
@@ -107,6 +108,7 @@
 import org.apache.pulsar.common.protocol.Commands;
 import org.apache.pulsar.common.util.netty.EventLoopUtil;
 import org.awaitility.Awaitility;
+import org.mockito.Mockito;
 import org.testng.Assert;
 import org.testng.annotations.AfterClass;
 import org.testng.annotations.BeforeClass;
@@ -1513,4 +1515,82 @@ public void testDynamicConfigurationsForceDeleteTenantAllowed() throws Exception
             assertTrue(conf.isForceDeleteTenantAllowed());
         });
     }
+
+
+    @Test
+    public void testBrokerStatsTopicLoadFailed() throws Exception {
+        admin.namespaces().createNamespace("prop/ns-test");
+
+        String persistentTopic = "persistent://prop/ns-test/topic1_" + UUID.randomUUID();
+        String nonPersistentTopic = "non-persistent://prop/ns-test/topic2_" + UUID.randomUUID();
+
+        BrokerService brokerService = pulsar.getBrokerService();
+        brokerService = Mockito.spy(brokerService);
+        // mock create persistent topic failed
+        Mockito
+                .doAnswer(invocation -> {
+                    CompletableFuture<ManagedLedgerConfig> f = new CompletableFuture<>();
+                    f.completeExceptionally(new RuntimeException("This is an exception"));
+                    return f;
+                })
+                .when(brokerService).getManagedLedgerConfig(Mockito.eq(TopicName.get(persistentTopic)));
+
+        // mock create non-persistent topic failed
+        Mockito
+                .doAnswer(inv -> {
+                    CompletableFuture<Void> f = new CompletableFuture<>();
+                    f.completeExceptionally(new RuntimeException("This is an exception"));
+                    return f;
+                })
+                .when(brokerService).checkTopicNsOwnership(Mockito.eq(nonPersistentTopic));
+
+
+        PulsarService pulsarService = pulsar;
+        Field field = PulsarService.class.getDeclaredField("brokerService");
+        field.setAccessible(true);
+        field.set(pulsarService, brokerService);
+
+        CompletableFuture<Producer<String>> producer = pulsarClient.newProducer(Schema.STRING)
+                .topic(persistentTopic)
+                .createAsync();
+        CompletableFuture<Producer<String>> producer1 = pulsarClient.newProducer(Schema.STRING)
+                .topic(nonPersistentTopic)
+                .createAsync();
+
+        producer.whenComplete((v, t) -> {
+            if (t == null) {
+                try {
+                    v.close();
+                } catch (PulsarClientException e) {
+                    // ignore
+                }
+            }
+        });
+        producer1.whenComplete((v, t) -> {
+            if (t == null) {
+                try {
+                    v.close();
+                } catch (PulsarClientException e) {
+                    // ignore
+                }
+            }
+        });
+
+        Awaitility.waitAtMost(2, TimeUnit.MINUTES).until(() -> {
+            String json = admin.brokerStats().getMetrics();
+            JsonArray metrics = new Gson().fromJson(json, JsonArray.class);
+            AtomicBoolean flag = new AtomicBoolean(false);
+
+            metrics.forEach(ele -> {
+                JsonObject obj = ((JsonObject) ele);
+                JsonObject metrics0 = (JsonObject) obj.get("metrics");
+                JsonPrimitive v = (JsonPrimitive) metrics0.get("brk_topic_load_failed_count");
+                if (null != v && v.getAsDouble() >= 2D) {
+                    flag.set(true);
+                }
+            });
+
+            return flag.get();
+        });
+    }
 }

pulsar-broker/src/test/java/org/apache/pulsar/broker/stats/PrometheusMetricsTest.java

@@ -333,6 +333,10 @@ public void testPerTopicStats() throws Exception {
         assertEquals(cm.size(), 1);
         assertEquals(cm.get(0).tags.get("cluster"), "test");
 
+        cm = (List<Metric>) metrics.get("topic_load_failed_total");
+        assertEquals(cm.size(), 1);
+        assertEquals(cm.get(0).tags.get("cluster"), "test");
+
         cm = (List<Metric>) metrics.get("pulsar_in_bytes_total");
         assertEquals(cm.size(), 2);
         assertEquals(cm.get(0).tags.get("topic"), "persistent://my-property/use/my-ns/my-topic2");