Revert "HBASE-23304: RPCs needed for client meta information lookup (#904) (#1098)"

This reverts commit 71f0354.

Author: ndimiduk

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java

@@ -1,4 +1,4 @@
-/*
+/**
  * 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
@@ -80,7 +80,6 @@
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.RegionLoadStats;
-import org.apache.hadoop.hbase.client.RegionReplicaUtil;
 import org.apache.hadoop.hbase.client.RegionStatesCount;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.Scan;
@@ -94,7 +93,6 @@
 import org.apache.hadoop.hbase.filter.ByteArrayComparable;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.io.TimeRange;
-import org.apache.hadoop.hbase.master.RegionState;
 import org.apache.hadoop.hbase.protobuf.ProtobufMagic;
 import org.apache.hadoop.hbase.protobuf.ProtobufMessageConverter;
 import org.apache.hadoop.hbase.quotas.QuotaScope;
@@ -377,9 +375,7 @@ private static IOException makeIOExceptionOfException(Exception e) {
    * @see #toServerName(org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.ServerName)
    */
   public static HBaseProtos.ServerName toServerName(final ServerName serverName) {
-    if (serverName == null) {
-      return null;
-    }
+    if (serverName == null) return null;
     HBaseProtos.ServerName.Builder builder =
       HBaseProtos.ServerName.newBuilder();
     builder.setHostName(serverName.getHostname());
@@ -3075,44 +3071,6 @@ public static ProcedureDescription buildProcedureDescription(String signature, S
     return builder.build();
   }
 
-  /**
-   * Get the Meta region state from the passed data bytes. Can handle both old and new style
-   * server names.
-   * @param data protobuf serialized data with meta server name.
-   * @param replicaId replica ID for this region
-   * @return RegionState instance corresponding to the serialized data.
-   * @throws DeserializationException if the data is invalid.
-   */
-  public static RegionState parseMetaRegionStateFrom(final byte[] data, int replicaId)
-      throws DeserializationException {
-    RegionState.State state = RegionState.State.OPEN;
-    ServerName serverName;
-    if (data != null && data.length > 0 && ProtobufUtil.isPBMagicPrefix(data)) {
-      try {
-        int prefixLen = ProtobufUtil.lengthOfPBMagic();
-        ZooKeeperProtos.MetaRegionServer rl =
-            ZooKeeperProtos.MetaRegionServer.parser().parseFrom(data, prefixLen,
-                data.length - prefixLen);
-        if (rl.hasState()) {
-          state = RegionState.State.convert(rl.getState());
-        }
-        HBaseProtos.ServerName sn = rl.getServer();
-        serverName = ServerName.valueOf(
-            sn.getHostName(), sn.getPort(), sn.getStartCode());
-      } catch (InvalidProtocolBufferException e) {
-        throw new DeserializationException("Unable to parse meta region location");
-      }
-    } else {
-      // old style of meta region location?
-      serverName = parseServerNameFrom(data);
-    }
-    if (serverName == null) {
-      state = RegionState.State.OFFLINE;
-    }
-    return new RegionState(RegionReplicaUtil.getRegionInfoForReplica(
-        RegionInfoBuilder.FIRST_META_REGIONINFO, replicaId), state, serverName);
-  }
-
   /**
    * Get a ServerName from the passed in data bytes.
    * @param data Data with a serialize server name in it; can handle the old style

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZNodePaths.java

@@ -41,8 +41,7 @@ public class ZNodePaths {
   // TODO: Replace this with ZooKeeper constant when ZOOKEEPER-277 is resolved.
   public static final char ZNODE_PATH_SEPARATOR = '/';
 
-  public static final String META_ZNODE_PREFIX_CONF_KEY = "zookeeper.znode.metaserver";
-  public static final String META_ZNODE_PREFIX = "meta-region-server";
+  private static final String META_ZNODE_PREFIX = "meta-region-server";
   private static final String DEFAULT_SNAPSHOT_CLEANUP_ZNODE = "snapshot-cleanup";
 
   // base znode for this cluster
@@ -105,7 +104,7 @@ public class ZNodePaths {
   public ZNodePaths(Configuration conf) {
     baseZNode = conf.get(ZOOKEEPER_ZNODE_PARENT, DEFAULT_ZOOKEEPER_ZNODE_PARENT);
     ImmutableMap.Builder<Integer, String> builder = ImmutableMap.builder();
-    metaZNodePrefix = conf.get(META_ZNODE_PREFIX_CONF_KEY, META_ZNODE_PREFIX);
+    metaZNodePrefix = conf.get("zookeeper.znode.metaserver", META_ZNODE_PREFIX);
     String defaultMetaReplicaZNode = ZNodePaths.joinZNode(baseZNode, metaZNodePrefix);
     builder.put(DEFAULT_REPLICA_ID, defaultMetaReplicaZNode);
     int numMetaReplicas = conf.getInt(META_REPLICAS_NUM, DEFAULT_META_REPLICA_NUM);
@@ -190,19 +189,7 @@ public String getZNodeForReplica(int replicaId) {
   }
 
   /**
-   * Parses the meta replicaId from the passed path.
-   * @param path the name of the full path which includes baseZNode.
-   * @return replicaId
-   */
-  public int getMetaReplicaIdFromPath(String path) {
-    // Extract the znode from path. The prefix is of the following format.
-    // baseZNode + PATH_SEPARATOR.
-    int prefixLen = baseZNode.length() + 1;
-    return getMetaReplicaIdFromZnode(path.substring(prefixLen));
-  }
-
-  /**
-   * Parse the meta replicaId from the passed znode
+   * Parse the meta replicaId from the passed znode name.
    * @param znode the name of the znode, does not include baseZNode
    * @return replicaId
    */

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

@@ -1196,47 +1196,3 @@ service HbckService {
   rpc FixMeta(FixMetaRequest)
     returns(FixMetaResponse);
 }
-
-/** Request and response to get the clusterID for this cluster */
-message GetClusterIdRequest {
-}
-message GetClusterIdResponse {
-  /** Not set if cluster ID could not be determined. */
-  optional string cluster_id = 1;
-}
-
-/** Request and response to get the currently active master name for this cluster */
-message GetActiveMasterRequest {
-}
-message GetActiveMasterResponse {
-  /** Not set if an active master could not be determined. */
-  optional ServerName server_name = 1;
-}
-
-/** Request and response to get the current list of meta region locations */
-message GetMetaRegionLocationsRequest {
-}
-message GetMetaRegionLocationsResponse {
-  /** Not set if meta region locations could not be determined. */
-  repeated RegionLocation meta_locations = 1;
-}
-
-/**
- * Implements all the RPCs needed by clients to look up cluster meta information needed for connection establishment.
- */
-service ClientMetaService {
-  /**
-   * Get Cluster ID for this cluster.
-   */
-  rpc GetClusterId(GetClusterIdRequest) returns(GetClusterIdResponse);
-
-  /**
-   * Get active master server name for this cluster.
-   */
-  rpc GetActiveMaster(GetActiveMasterRequest) returns(GetActiveMasterResponse);
-
-  /**
-   * Get current meta replicas' region locations.
-   */
-  rpc GetMetaRegionLocations(GetMetaRegionLocationsRequest) returns(GetMetaRegionLocationsResponse);
-}

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

@@ -1,4 +1,4 @@
-/*
+/**
  *
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -17,24 +17,25 @@
  * limitations under the License.
  */
 package org.apache.hadoop.hbase.master;
+
 import java.io.IOException;
-import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
+
+import org.apache.hadoop.hbase.zookeeper.MasterAddressTracker;
+import org.apache.hadoop.hbase.zookeeper.ZKUtil;
+import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
+import org.apache.hadoop.hbase.zookeeper.ZNodePaths;
+import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.ZNodeClearer;
 import org.apache.hadoop.hbase.exceptions.DeserializationException;
 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
-import org.apache.hadoop.hbase.zookeeper.MasterAddressTracker;
+import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.zookeeper.ZKListener;
-import org.apache.hadoop.hbase.zookeeper.ZKUtil;
-import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
-import org.apache.hadoop.hbase.zookeeper.ZNodePaths;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.zookeeper.KeeperException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 
 /**
  * Handles everything on master-side related to master election.
@@ -56,18 +57,12 @@ public class ActiveMasterManager extends ZKListener {
   final AtomicBoolean clusterHasActiveMaster = new AtomicBoolean(false);
   final AtomicBoolean clusterShutDown = new AtomicBoolean(false);
 
-  // This server's information.
   private final ServerName sn;
   private int infoPort;
   private final Server master;
 
-  // Active master's server name. Invalidated anytime active master changes (based on ZK
-  // notifications) and lazily fetched on-demand.
-  // ServerName is immutable, so we don't need heavy synchronization around it.
-  private volatile ServerName activeMasterServerName;
-
   /**
-   * @param watcher ZK watcher
+   * @param watcher
    * @param sn ServerName
    * @param master In an instance of a Master.
    */
@@ -111,30 +106,6 @@ void handle(final String path) {
     }
   }
 
-  /**
-   * Fetches the active master's ServerName from zookeeper.
-   */
-  private void fetchAndSetActiveMasterServerName() {
-    LOG.debug("Attempting to fetch active master sn from zk");
-    try {
-      activeMasterServerName = MasterAddressTracker.getMasterAddress(watcher);
-    } catch (IOException | KeeperException e) {
-      // Log and ignore for now and re-fetch later if needed.
-      LOG.error("Error fetching active master information", e);
-    }
-  }
-
-  public Optional<ServerName> getActiveMasterServerName() {
-    if (!clusterHasActiveMaster.get()) {
-      return Optional.empty();
-    }
-    if (activeMasterServerName == null) {
-      fetchAndSetActiveMasterServerName();
-    }
-    // It could still be null, but return whatever we have.
-    return Optional.ofNullable(activeMasterServerName);
-  }
-
   /**
    * Handle a change in the master node.  Doesn't matter whether this was called
    * from a nodeCreated or nodeDeleted event because there are no guarantees
@@ -163,9 +134,6 @@ private void handleMasterNodeChange() {
           // Notify any thread waiting to become the active master
           clusterHasActiveMaster.notifyAll();
         }
-        // Reset the active master sn. Will be re-fetched later if needed.
-        // We don't want to make a synchronous RPC under a monitor.
-        activeMasterServerName = null;
       }
     } catch (KeeperException ke) {
       master.abort("Received an unexpected KeeperException, aborting", ke);
@@ -183,8 +151,8 @@ private void handleMasterNodeChange() {
    * @param checkInterval the interval to check if the master is stopped
    * @param startupStatus the monitor status to track the progress
    * @return True if no issue becoming active master else false if another
-   *   master was running or if some other problem (zookeeper, stop flag has been
-   *   set on this Master)
+   * master was running or if some other problem (zookeeper, stop flag has been
+   * set on this Master)
    */
   boolean blockUntilBecomingActiveMaster(
       int checkInterval, MonitoredTask startupStatus) {
@@ -210,14 +178,10 @@ boolean blockUntilBecomingActiveMaster(
           // We are the master, return
           startupStatus.setStatus("Successfully registered as active master.");
           this.clusterHasActiveMaster.set(true);
-          activeMasterServerName = sn;
           LOG.info("Registered as active master=" + this.sn);
           return true;
         }
 
-        // Invalidate the active master name so that subsequent requests do not get any stale
-        // master information. Will be re-fetched if needed.
-        activeMasterServerName = null;
         // There is another active master running elsewhere or this is a restart
         // and the master ephemeral node has not expired yet.
         this.clusterHasActiveMaster.set(true);
@@ -244,8 +208,7 @@ boolean blockUntilBecomingActiveMaster(
             ZKUtil.deleteNode(this.watcher, this.watcher.getZNodePaths().masterAddressZNode);
 
             // We may have failed to delete the znode at the previous step, but
-            //  we delete the file anyway: a second attempt to delete the znode is likely to fail
-            //  again.
+            //  we delete the file anyway: a second attempt to delete the znode is likely to fail again.
             ZNodeClearer.deleteMyEphemeralNodeOnDisk();
           } else {
             msg = "Another master is the active master, " + currentMaster +