Backport "HBASE-30473 Expose Master switch states as numeric metrics (#8758)" to branch-2.6

hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/master/MetricsMasterSource.java

@@ -67,6 +67,16 @@ public interface MetricsMasterSource extends BaseSource {
 
   String CLUSTER_REQUESTS_NAME = "clusterRequests";
   String OLD_WAL_DIR_SIZE_NAME = "oldWALsDirSize";
+  String BALANCER_ENABLED_NAME = "balancerEnabled";
+  String NORMALIZER_ENABLED_NAME = "normalizerEnabled";
+  String SPLIT_ENABLED_NAME = "splitEnabled";
+  String MERGE_ENABLED_NAME = "mergeEnabled";
+  String CLEANER_CHORE_ENABLED_NAME = "cleanerChoreEnabled";
+  String CATALOG_JANITOR_ENABLED_NAME = "catalogJanitorEnabled";
+  String SNAPSHOT_CLEANUP_ENABLED_NAME = "snapshotCleanupEnabled";
+  String REPLICATION_PEER_MODIFICATION_ENABLED_NAME = "replicationPeerModificationEnabled";
+  String RPC_THROTTLE_ENABLED_NAME = "rpcThrottleEnabled";
+  String SWITCH_STATE_DESC = "Switch state: 1 enabled, 0 disabled";
   String MASTER_ACTIVE_TIME_DESC = "Master Active Time";
   String MASTER_START_TIME_DESC = "Master Start Time";
   String MASTER_FINISHED_INITIALIZATION_TIME_DESC =

hbase-hadoop-compat/src/main/java/org/apache/hadoop/hbase/master/MetricsMasterWrapper.java

@@ -157,4 +157,11 @@ public interface MetricsMasterWrapper {
    * Get the size of old WALs directory in bytes.
    */
   long getOldWALsDirSize();
+
+  /**
+   * Returns known switch states (1 enabled, 0 disabled), or an empty map unless this Master is
+   * active and initialized. Unavailable states are omitted. Implementations must not perform remote
+   * reads.
+   */
+  Map<String, Integer> getSwitchStates();
 }

hbase-hadoop2-compat/src/main/java/org/apache/hadoop/hbase/master/MetricsMasterSourceImpl.java

@@ -109,6 +109,9 @@ public void getMetrics(MetricsCollector metricsCollector, boolean all) {
           String.valueOf(masterWrapper.getIsActiveMaster()))
         .addGauge(Interns.info(OLD_WAL_DIR_SIZE_NAME, OLD_WAL_DIR_SIZE_DESC),
           masterWrapper.getOldWALsDirSize());
+
+      masterWrapper.getSwitchStates().forEach((name, state) -> metricsRecordBuilder
+        .addGauge(Interns.info(name, SWITCH_STATE_DESC), state));
     }
 
     metricsRegistry.snapshot(metricsRecordBuilder, all);

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MetricsMasterWrapperImpl.java

@@ -25,10 +25,13 @@
 import org.apache.commons.lang3.StringUtils;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.MasterSwitchType;
 import org.apache.hadoop.hbase.master.procedure.MasterProcedureEnv;
 import org.apache.hadoop.hbase.procedure2.Procedure;
 import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
+import org.apache.hadoop.hbase.quotas.MasterQuotaManager;
 import org.apache.hadoop.hbase.quotas.QuotaObserverChore;
+import org.apache.hadoop.hbase.quotas.QuotaUtil;
 import org.apache.hadoop.hbase.quotas.SpaceQuotaSnapshot;
 import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
 import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
@@ -238,4 +241,34 @@ public long getOldWALsDirSize() {
     }
     return master.getMasterWalManager().getOldWALsDirSize();
   }
+
+  @Override
+  public Map<String, Integer> getSwitchStates() {
+    if (!master.isActiveMaster() || !master.isInitialized()) {
+      return Collections.emptyMap();
+    }
+    Map<String, Integer> states = new HashMap<>();
+    states.put(MetricsMasterSource.BALANCER_ENABLED_NAME, master.isBalancerOn() ? 1 : 0);
+    states.put(MetricsMasterSource.NORMALIZER_ENABLED_NAME, master.isNormalizerOn() ? 1 : 0);
+    states.put(MetricsMasterSource.SPLIT_ENABLED_NAME,
+      master.isSplitOrMergeEnabled(MasterSwitchType.SPLIT) ? 1 : 0);
+    states.put(MetricsMasterSource.MERGE_ENABLED_NAME,
+      master.isSplitOrMergeEnabled(MasterSwitchType.MERGE) ? 1 : 0);
+    states.put(MetricsMasterSource.CLEANER_CHORE_ENABLED_NAME,
+      master.isCleanerChoreEnabled() ? 1 : 0);
+    states.put(MetricsMasterSource.CATALOG_JANITOR_ENABLED_NAME,
+      master.isCatalogJanitorEnabled() ? 1 : 0);
+    states.put(MetricsMasterSource.SNAPSHOT_CLEANUP_ENABLED_NAME,
+      master.snapshotCleanupStateStore.get() ? 1 : 0);
+    states.put(MetricsMasterSource.REPLICATION_PEER_MODIFICATION_ENABLED_NAME,
+      master.isReplicationPeerModificationEnabled() ? 1 : 0);
+    MasterQuotaManager quotaManager = master.getMasterQuotaManager();
+    if (quotaManager != null) {
+      states.put(MetricsMasterSource.RPC_THROTTLE_ENABLED_NAME,
+        quotaManager.isRpcThrottleEnabled() ? 1 : 0);
+    } else if (!QuotaUtil.isQuotaEnabled(master.getConfiguration())) {
+      states.put(MetricsMasterSource.RPC_THROTTLE_ENABLED_NAME, 0);
+    }
+    return states;
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/quotas/MasterQuotaManager.java

@@ -427,7 +427,7 @@ public IsRpcThrottleEnabledResponse isRpcThrottleEnabled(IsRpcThrottleEnabledReq
     }
   }
 
-  public boolean isRpcThrottleEnabled() throws IOException {
+  public boolean isRpcThrottleEnabled() {
     return initialized && masterServices.getRpcThrottleStateStore().get();
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMasterMetrics.java

@@ -20,6 +20,7 @@
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.util.HashMap;
+import java.util.Map;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CompatibilityFactory;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
@@ -28,6 +29,7 @@
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.StartMiniClusterOption;
 import org.apache.hadoop.hbase.YouAreDeadException;
+import org.apache.hadoop.hbase.client.Admin;
 import org.apache.hadoop.hbase.regionserver.RSRpcServices;
 import org.apache.hadoop.hbase.test.MetricsAssertHelper;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
@@ -121,6 +123,44 @@ public static void after() throws Exception {
     }
   }
 
+  @FunctionalInterface
+  private interface SwitchSetter {
+    void accept(boolean enabled) throws IOException;
+  }
+
+  @Test
+  public void testSwitchMetricsFollowAdminChanges() throws IOException {
+    Admin admin = TEST_UTIL.getAdmin();
+    MetricsMasterSource source = master.getMasterMetrics().getMetricsSource();
+    Map<String, SwitchSetter> switches = new HashMap<>();
+    switches.put(MetricsMasterSource.BALANCER_ENABLED_NAME,
+      enabled -> admin.balancerSwitch(enabled, false));
+    switches.put(MetricsMasterSource.NORMALIZER_ENABLED_NAME, admin::normalizerSwitch);
+    switches.put(MetricsMasterSource.SPLIT_ENABLED_NAME,
+      enabled -> admin.splitSwitch(enabled, false));
+    switches.put(MetricsMasterSource.MERGE_ENABLED_NAME,
+      enabled -> admin.mergeSwitch(enabled, false));
+    switches.put(MetricsMasterSource.CLEANER_CHORE_ENABLED_NAME, admin::cleanerChoreSwitch);
+    switches.put(MetricsMasterSource.CATALOG_JANITOR_ENABLED_NAME, admin::catalogJanitorSwitch);
+    switches.put(MetricsMasterSource.SNAPSHOT_CLEANUP_ENABLED_NAME,
+      enabled -> admin.snapshotCleanupSwitch(enabled, false));
+    switches.put(MetricsMasterSource.REPLICATION_PEER_MODIFICATION_ENABLED_NAME,
+      admin::replicationPeerModificationSwitch);
+    Map<String, Integer> initialStates = new MetricsMasterWrapperImpl(master).getSwitchStates();
+    for (Map.Entry<String, SwitchSetter> entry : switches.entrySet()) {
+      try {
+        for (boolean enabled : new boolean[] { false, true }) {
+          entry.getValue().accept(enabled);
+          metricsHelper.assertGauge(entry.getKey(), enabled ? 1L : 0L, source);
+        }
+      } finally {
+        entry.getValue().accept(initialStates.get(entry.getKey()) == 1);
+      }
+    }
+    // Quota support is disabled by default.
+    metricsHelper.assertGauge(MetricsMasterSource.RPC_THROTTLE_ENABLED_NAME, 0L, source);
+  }
+
   @Test
   public void testClusterRequests() throws Exception {
     // sending fake request to master to see how metric value has changed

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMasterRepairMode.java

@@ -17,15 +17,20 @@
  */
 package org.apache.hadoop.hbase.master;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Arrays;
+import java.util.Map;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.CompatibilityFactory;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.StartMiniClusterOption;
@@ -39,6 +44,8 @@
 import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Table;
+import org.apache.hadoop.hbase.quotas.QuotaUtil;
+import org.apache.hadoop.hbase.test.MetricsAssertHelper;
 import org.apache.hadoop.hbase.testclassification.LargeTests;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -98,6 +105,33 @@ public void testNewCluster() throws Exception {
     }
   }
 
+  @Test
+  public void testSwitchMetricsWithQuotasEnabled() throws Exception {
+    enableMaintenanceMode();
+    TEST_UTIL.getConfiguration().setBoolean(QuotaUtil.QUOTA_CONF_KEY, true);
+    TEST_UTIL.startMiniCluster(
+      StartMiniClusterOption.builder().numRegionServers(0).numDataNodes(1).build());
+
+    HMaster master = TEST_UTIL.getMiniHBaseCluster().getMaster();
+    assertTrue(master.isInMaintenanceMode());
+    assertNull(master.getMasterQuotaManager());
+    MetricsMasterSource source = master.getMasterMetrics().getMetricsSource();
+    MetricsAssertHelper metricsHelper = CompatibilityFactory.getInstance(MetricsAssertHelper.class);
+    Map<String, Integer> states = new MetricsMasterWrapperImpl(master).getSwitchStates();
+    assertEquals(8, states.size());
+    assertFalse(states.containsKey(MetricsMasterSource.RPC_THROTTLE_ENABLED_NAME));
+    assertFalse(
+      metricsHelper.checkGaugeExists(MetricsMasterSource.RPC_THROTTLE_ENABLED_NAME, source));
+    states.forEach((name, state) -> {
+      assertTrue(state == 0 || state == 1);
+      metricsHelper.assertGauge(name, state.longValue(), source);
+    });
+    metricsHelper.assertGauge(MetricsMasterSource.BALANCER_ENABLED_NAME, 0L, source);
+    metricsHelper.assertGauge(MetricsMasterSource.NORMALIZER_ENABLED_NAME, 0L, source);
+    metricsHelper.assertGauge(MetricsMasterSource.SPLIT_ENABLED_NAME, 0L, source);
+    metricsHelper.assertGauge(MetricsMasterSource.MERGE_ENABLED_NAME, 0L, source);
+  }
+
   @Test
   public void testExistingCluster() throws Exception {
     TableName testRepairMode = TableName.valueOf(testMethodName);