HBASE-21938 Add a new ClusterMetrics.Option SERVERS_NAME to only return the live region servers's name without metrics

Signed-off-by: Guanghao Zhang <zghao@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetrics.java

@@ -139,6 +139,8 @@ public interface ClusterMetrics {
 
   int getMasterInfoPort();
 
+  List<ServerName> getServersName();
+
   /**
    * @return the average cluster load
    */
@@ -193,6 +195,10 @@ public interface ClusterMetrics {
     /**
      * metrics info port
      */
-    MASTER_INFO_PORT
+    MASTER_INFO_PORT,
+    /**
+     * metrics about live region servers name
+     */
+    SERVERS_NAME
   }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterMetricsBuilder.java

@@ -33,6 +33,7 @@ import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
 import org.apache.hbase.thirdparty.com.google.protobuf.UnsafeByteOperations;
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ClusterStatusProtos.Option;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.FSProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;
 
@@ -67,7 +68,9 @@ public final class ClusterMetricsBuilder {
                 .setRegionState(r.convert())
                 .build())
             .collect(Collectors.toList()))
-        .setMasterInfoPort(metrics.getMasterInfoPort());
+        .setMasterInfoPort(metrics.getMasterInfoPort())
+        .addAllServersName(metrics.getServersName().stream().map(ProtobufUtil::toServerName)
+            .collect(Collectors.toList()));
     if (metrics.getMasterName() != null) {
       builder.setMaster(ProtobufUtil.toServerName((metrics.getMasterName())));
     }
@@ -103,6 +106,8 @@ public final class ClusterMetricsBuilder {
             .collect(Collectors.toList()))
         .setMasterCoprocessorNames(proto.getMasterCoprocessorsList().stream()
             .map(HBaseProtos.Coprocessor::getName)
+            .collect(Collectors.toList()))
+        .setServerNames(proto.getServersNameList().stream().map(ProtobufUtil::toServerName)
             .collect(Collectors.toList()));
     if (proto.hasClusterId()) {
       builder.setClusterId(ClusterId.convert(proto.getClusterId()).toString());
@@ -142,6 +147,7 @@ public final class ClusterMetricsBuilder {
       case MASTER: return ClusterMetrics.Option.MASTER;
       case BACKUP_MASTERS: return ClusterMetrics.Option.BACKUP_MASTERS;
       case BALANCER_ON: return ClusterMetrics.Option.BALANCER_ON;
+      case SERVERS_NAME: return ClusterMetrics.Option.SERVERS_NAME;
       case MASTER_INFO_PORT: return ClusterMetrics.Option.MASTER_INFO_PORT;
       // should not reach here
       default: throw new IllegalArgumentException("Invalid option: " + option);
@@ -164,6 +170,7 @@ public final class ClusterMetricsBuilder {
       case MASTER: return ClusterStatusProtos.Option.MASTER;
       case BACKUP_MASTERS: return ClusterStatusProtos.Option.BACKUP_MASTERS;
       case BALANCER_ON: return ClusterStatusProtos.Option.BALANCER_ON;
+      case SERVERS_NAME: return Option.SERVERS_NAME;
       case MASTER_INFO_PORT: return ClusterStatusProtos.Option.MASTER_INFO_PORT;
       // should not reach here
       default: throw new IllegalArgumentException("Invalid option: " + option);
@@ -206,6 +213,7 @@ public final class ClusterMetricsBuilder {
   @Nullable
   private Boolean balancerOn;
   private int masterInfoPort;
+  private List<ServerName> serversName = Collections.emptyList();
 
   private ClusterMetricsBuilder() {
   }
@@ -251,6 +259,10 @@ public final class ClusterMetricsBuilder {
     this.masterInfoPort = value;
     return this;
   }
+  public ClusterMetricsBuilder setServerNames(List<ServerName> serversName) {
+    this.serversName = serversName;
+    return this;
+  }
   public ClusterMetrics build() {
     return new ClusterMetricsImpl(
         hbaseVersion,
@@ -262,7 +274,8 @@ public final class ClusterMetricsBuilder {
         clusterId,
         masterCoprocessorNames,
         balancerOn,
-        masterInfoPort);
+        masterInfoPort,
+        serversName);
   }
   private static class ClusterMetricsImpl implements ClusterMetrics {
     @Nullable
@@ -279,6 +292,7 @@ public final class ClusterMetricsBuilder {
     @Nullable
     private final Boolean balancerOn;
     private final int masterInfoPort;
+    private final List<ServerName> serversName;
 
     ClusterMetricsImpl(String hbaseVersion, List<ServerName> deadServerNames,
         Map<ServerName, ServerMetrics> liveServerMetrics,
@@ -288,7 +302,8 @@ public final class ClusterMetricsBuilder {
         String clusterId,
         List<String> masterCoprocessorNames,
         Boolean balancerOn,
-        int masterInfoPort) {
+        int masterInfoPort,
+        List<ServerName> serversName) {
       this.hbaseVersion = hbaseVersion;
       this.deadServerNames = Preconditions.checkNotNull(deadServerNames);
       this.liveServerMetrics = Preconditions.checkNotNull(liveServerMetrics);
@@ -299,6 +314,7 @@ public final class ClusterMetricsBuilder {
       this.masterCoprocessorNames = Preconditions.checkNotNull(masterCoprocessorNames);
       this.balancerOn = balancerOn;
       this.masterInfoPort = masterInfoPort;
+      this.serversName = serversName;
     }
 
     @Override
@@ -351,6 +367,11 @@ public final class ClusterMetricsBuilder {
       return masterInfoPort;
     }
 
+    @Override
+    public List<ServerName> getServersName() {
+      return Collections.unmodifiableList(serversName);
+    }
+
     @Override
     public String toString() {
       StringBuilder sb = new StringBuilder(1024);
@@ -365,11 +386,17 @@ public final class ClusterMetricsBuilder {
       }
 
       int serversSize = getLiveServerMetrics().size();
-      sb.append("\nNumber of live region servers: " + serversSize);
+      int serversNameSize = getServersName().size();
+      sb.append("\nNumber of live region servers: "
+          + (serversSize > 0 ? serversSize : serversNameSize));
       if (serversSize > 0) {
         for (ServerName serverName : getLiveServerMetrics().keySet()) {
           sb.append("\n  " + serverName.getServerName());
         }
+      } else if (serversNameSize > 0) {
+        for (ServerName serverName : getServersName()) {
+          sb.append("\n  " + serverName.getServerName());
+        }
       }
 
       int deadServerSize = getDeadServerNames().size();

hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterStatus.java

@@ -344,6 +344,11 @@ public class ClusterStatus implements ClusterMetrics {
     return metrics.getMasterInfoPort();
   }
 
+  @Override
+  public List<ServerName> getServersName() {
+    return metrics.getServersName();
+  }
+
   @Override
   public String toString() {
     StringBuilder sb = new StringBuilder(1024);
@@ -358,11 +363,17 @@ public class ClusterStatus implements ClusterMetrics {
     }
 
     int serversSize = getServersSize();
-    sb.append("\nNumber of live region servers: " + serversSize);
+    int serversNameSize = getServersName().size();
+    sb.append("\nNumber of live region servers: "
+        + (serversSize > 0 ? serversSize : serversNameSize));
     if (serversSize > 0) {
       for (ServerName serverName : metrics.getLiveServerMetrics().keySet()) {
         sb.append("\n  " + serverName.getServerName());
       }
+    } else if (serversNameSize > 0) {
+      for (ServerName serverName : getServersName()) {
+        sb.append("\n  " + serverName.getServerName());
+      }
     }
 
     int deadServerSize = metrics.getDeadServerNames().size();

hbase-protocol-shaded/src/main/protobuf/ClusterStatus.proto

@@ -232,6 +232,7 @@ message ClusterStatus {
   repeated ServerName backup_masters = 8;
   optional bool balancer_on = 9;
   optional int32 master_info_port = 10 [default = -1];
+  repeated ServerName servers_name = 11;
 }
 
 enum Option {
@@ -245,4 +246,5 @@ enum Option {
   REGIONS_IN_TRANSITION = 7;
   BALANCER_ON = 8;
   MASTER_INFO_PORT = 9;
+  SERVERS_NAME = 10;
 }

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

@@ -2801,6 +2801,12 @@ public class HMaster extends HRegionServer implements MasterServices {
           }
           break;
         }
+        case SERVERS_NAME: {
+          if (serverManager != null) {
+            builder.setServerNames(serverManager.getOnlineServersList());
+          }
+          break;
+        }
       }
     }
     return builder.build();

hbase-server/src/test/java/org/apache/hadoop/hbase/TestClientClusterMetrics.java

@@ -96,6 +96,7 @@ public class TestClientClusterMetrics {
     Assert.assertEquals(origin.getLiveServerMetrics().size(),
         defaults.getLiveServerMetrics().size());
     Assert.assertEquals(origin.getMasterInfoPort(), defaults.getMasterInfoPort());
+    Assert.assertEquals(origin.getServersName().size(), defaults.getServersName().size());
   }
 
   @Test
@@ -121,6 +122,7 @@ public class TestClientClusterMetrics {
       Assert.assertEquals(origin.getLiveServerMetrics().size(),
         defaults.getLiveServerMetrics().size());
       Assert.assertEquals(origin.getMasterInfoPort(), defaults.getMasterInfoPort());
+      Assert.assertEquals(origin.getServersName().size(), defaults.getServersName().size());
     }
   }
 
@@ -146,7 +148,8 @@ public class TestClientClusterMetrics {
       }
     });
     // Retrieve live servers and dead servers info.
-    EnumSet<Option> options = EnumSet.of(Option.LIVE_SERVERS, Option.DEAD_SERVERS);
+    EnumSet<Option> options =
+        EnumSet.of(Option.LIVE_SERVERS, Option.DEAD_SERVERS, Option.SERVERS_NAME);
     ClusterMetrics metrics = ADMIN.getClusterMetrics(options);
     Assert.assertNotNull(metrics);
     // exclude a dead region server
@@ -160,6 +163,8 @@ public class TestClientClusterMetrics {
     Assert.assertEquals(1, metrics.getDeadServerNames().size());
     ServerName deadServerName = metrics.getDeadServerNames().iterator().next();
     Assert.assertEquals(DEAD.getServerName(), deadServerName);
+    Assert.assertNotNull(metrics.getServersName());
+    Assert.assertEquals(numRs, metrics.getServersName().size());
   }
 
   @Test

hbase-server/src/test/java/org/apache/hadoop/hbase/TestClientClusterStatus.java

@@ -37,7 +37,6 @@ import org.apache.hadoop.hbase.regionserver.HRegionServer;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.util.JVMClusterUtil.MasterThread;
 import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
-import org.apache.hadoop.hbase.util.Threads;
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.BeforeClass;
@@ -99,6 +98,7 @@ public class TestClientClusterStatus {
     Assert.assertTrue(origin.getServersSize() == defaults.getServersSize());
     Assert.assertTrue(origin.getMasterInfoPort() == defaults.getMasterInfoPort());
     Assert.assertTrue(origin.equals(defaults));
+    Assert.assertTrue(origin.getServersName().size() == defaults.getServersName().size());
   }
 
   @Test
@@ -136,7 +136,8 @@ public class TestClientClusterStatus {
       }
     });
     // Retrieve live servers and dead servers info.
-    EnumSet<Option> options = EnumSet.of(Option.LIVE_SERVERS, Option.DEAD_SERVERS);
+    EnumSet<Option> options =
+        EnumSet.of(Option.LIVE_SERVERS, Option.DEAD_SERVERS, Option.SERVERS_NAME);
     ClusterStatus status = new ClusterStatus(ADMIN.getClusterMetrics(options));
     checkPbObjectNotNull(status);
     Assert.assertNotNull(status);
@@ -152,6 +153,8 @@ public class TestClientClusterStatus {
     Assert.assertEquals(1, status.getDeadServersSize());
     ServerName deadServerName = status.getDeadServerNames().iterator().next();
     Assert.assertEquals(DEAD.getServerName(), deadServerName);
+    Assert.assertNotNull(status.getServersName());
+    Assert.assertEquals(numRs, status.getServersName().size());
   }
 
   @Test