HDDS-11388. Fix unnecessary call to the DB for ContainerBalancer#getBalancerStatusInfo (apache#7224)

Author: ivandika3

hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/container/balancer/ContainerBalancer.java

@@ -183,17 +183,19 @@ public ContainerBalancerTask.Status getBalancerStatus() {
    * @return balancer status info if balancer started
    */
   public ContainerBalancerStatusInfo getBalancerStatusInfo() throws IOException {
-    if (isBalancerRunning()) {
-      ContainerBalancerConfigurationProto configProto = readConfiguration(ContainerBalancerConfigurationProto.class);
-      return new ContainerBalancerStatusInfo(
-              this.startedAt,
-              configProto,
-              task.getCurrentIterationsStatistic()
-      );
-    } else {
+    lock.lock();
+    try {
+      if (isBalancerRunning()) {
+        return new ContainerBalancerStatusInfo(
+            this.startedAt,
+            config.toProtobufBuilder().setShouldRun(true).build(),
+            task.getCurrentIterationsStatistic()
+        );
+      }
       return null;
+    } finally {
+      lock.unlock();
     }
-
   }
   /**
    * Checks if ContainerBalancer is in valid state to call stop.

hadoop-hdds/server-scm/src/test/java/org/apache/hadoop/hdds/scm/container/balancer/TestContainerBalancer.java

@@ -44,6 +44,7 @@
 import static org.apache.hadoop.hdds.HddsConfigKeys.HDDS_NODE_REPORT_INTERVAL;
 import static org.apache.hadoop.hdds.HddsConfigKeys.HDDS_SCM_WAIT_TIME_AFTER_SAFE_MODE_EXIT;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertThrowsExactly;
 import static org.junit.jupiter.api.Assertions.assertSame;
@@ -257,6 +258,22 @@ public void testDelayedStartOnSCMStatusChange()
     stopBalancer();
   }
 
+  @Test
+  public void testGetBalancerStatusInfo() throws Exception {
+    startBalancer(balancerConfiguration);
+    assertSame(ContainerBalancerTask.Status.RUNNING, containerBalancer.getBalancerStatus());
+
+    // Assert the configuration fields that were explicitly set
+    ContainerBalancerStatusInfo status = containerBalancer.getBalancerStatusInfo();
+    assertEquals(balancerConfiguration.getThreshold(),
+        Double.parseDouble(status.getConfiguration().getUtilizationThreshold()));
+    assertEquals(balancerConfiguration.getIterations(), status.getConfiguration().getIterations());
+    assertEquals(balancerConfiguration.getTriggerDuEnable(), status.getConfiguration().getTriggerDuBeforeMoveEnable());
+
+    stopBalancer();
+    assertSame(ContainerBalancerTask.Status.STOPPED, containerBalancer.getBalancerStatus());
+  }
+
   private void startBalancer(ContainerBalancerConfiguration config)
       throws IllegalContainerBalancerStateException, IOException,
       InvalidContainerBalancerConfigurationException, TimeoutException {

hadoop-ozone/dist/src/main/smoketest/balancer/testBalancer.robot

@@ -67,7 +67,6 @@ Run Container Balancer
 
 Wait Finish Of Balancing
     ${result} =             Execute                         ozone admin containerbalancer status
-                            Should Contain                  ${result}             ContainerBalancer is Running.
                             Wait Until Keyword Succeeds      6min    10sec    ContainerBalancer is Not Running
                             Sleep                   60000ms