Create tserver.group, add group to location information

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientContext.java

@@ -498,7 +498,7 @@ public String getRootTabletLocation() {
       return null;
     }
 
-    return loc.getHostPort();
+    return loc.getServerInstance().getHostPort();
   }
 
   /**

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCache.java

@@ -43,9 +43,9 @@
 import org.apache.accumulo.core.metadata.MetadataCachedTabletObtainer;
 import org.apache.accumulo.core.metadata.MetadataTable;
 import org.apache.accumulo.core.metadata.RootTable;
+import org.apache.accumulo.core.metadata.TServerInstance;
 import org.apache.accumulo.core.singletons.SingletonManager;
 import org.apache.accumulo.core.singletons.SingletonService;
-import org.apache.accumulo.core.util.Interner;
 import org.apache.accumulo.core.util.UtilWaitThread;
 import org.apache.hadoop.io.Text;
 
@@ -270,43 +270,37 @@ public List<CachedTablet> getCachedTablets() {
   }
 
   public static class CachedTablet {
-    private static final Interner<String> interner = new Interner<>();
 
     private final KeyExtent tablet_extent;
-    private final String tserverLocation;
-    private final String tserverSession;
+    private final TServerInstance tsi;
     private final TabletHostingGoal goal;
     private final boolean hostingRequested;
 
     private final Long creationTime = System.nanoTime();
 
-    public CachedTablet(KeyExtent tablet_extent, String tablet_location, String session,
-        TabletHostingGoal goal, boolean hostingRequested) {
+    public CachedTablet(KeyExtent tablet_extent, TServerInstance instance, TabletHostingGoal goal,
+        boolean hostingRequested) {
       checkArgument(tablet_extent != null, "tablet_extent is null");
-      checkArgument(tablet_location != null, "tablet_location is null");
-      checkArgument(session != null, "session is null");
+      checkArgument(instance != null, "tablet_location is null");
       this.tablet_extent = tablet_extent;
-      this.tserverLocation = interner.intern(tablet_location);
-      this.tserverSession = interner.intern(session);
+      this.tsi = instance;
       this.goal = Objects.requireNonNull(goal);
       this.hostingRequested = hostingRequested;
     }
 
-    public CachedTablet(KeyExtent tablet_extent, Optional<String> tablet_location,
-        Optional<String> session, TabletHostingGoal goal, boolean hostingRequested) {
+    public CachedTablet(KeyExtent tablet_extent, Optional<TServerInstance> tablet_location,
+        TabletHostingGoal goal, boolean hostingRequested) {
       checkArgument(tablet_extent != null, "tablet_extent is null");
       this.tablet_extent = tablet_extent;
-      this.tserverLocation = tablet_location.map(interner::intern).orElse(null);
-      this.tserverSession = session.map(interner::intern).orElse(null);
+      this.tsi = tablet_location.orElse(null);
       this.goal = Objects.requireNonNull(goal);
       this.hostingRequested = hostingRequested;
     }
 
     public CachedTablet(KeyExtent tablet_extent, TabletHostingGoal goal, boolean hostingRequested) {
       checkArgument(tablet_extent != null, "tablet_extent is null");
       this.tablet_extent = tablet_extent;
-      this.tserverLocation = null;
-      this.tserverSession = null;
+      this.tsi = null;
       this.goal = Objects.requireNonNull(goal);
       this.hostingRequested = hostingRequested;
     }
@@ -325,25 +319,33 @@ && getTserverSession().equals(otl.getTserverSession()) && getGoal() == otl.getGo
 
     @Override
     public int hashCode() {
-      return Objects.hash(getExtent(), tserverLocation, tserverSession, goal, hostingRequested);
+      return Objects.hash(getExtent(), tsi, goal, hostingRequested);
     }
 
     @Override
     public String toString() {
       return "(" + getExtent() + "," + getTserverLocation() + "," + getTserverSession() + ","
-          + getGoal() + ")";
+          + getResourceGroup() + "," + getGoal() + ")";
     }
 
     public KeyExtent getExtent() {
       return tablet_extent;
     }
 
     public Optional<String> getTserverLocation() {
-      return Optional.ofNullable(tserverLocation);
+      return Optional.ofNullable(tsi == null ? null : tsi.getHostPort());
     }
 
     public Optional<String> getTserverSession() {
-      return Optional.ofNullable(tserverSession);
+      return Optional.ofNullable(tsi == null ? null : tsi.getSession());
+    }
+
+    public Optional<String> getResourceGroup() {
+      return Optional.ofNullable(tsi == null ? null : tsi.getGroup());
+    }
+
+    public Optional<TServerInstance> getServer() {
+      return Optional.ofNullable(tsi == null ? null : tsi);
     }
 
     /**

core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCacheImpl.java

@@ -541,8 +541,8 @@ public CachedTablet findTablet(ClientContext context, Text row, boolean skipRow,
     OpTimer timer = null;
 
     if (log.isTraceEnabled()) {
-      log.trace("tid={} Locating tablet  table={} row={} skipRow={}",
-          Thread.currentThread().getId(), tableId, TextUtil.truncate(row), skipRow);
+      log.trace("tid={} Locating tablet table={} row={} skipRow={}", Thread.currentThread().getId(),
+          tableId, TextUtil.truncate(row), skipRow);
       timer = new OpTimer().start();
     }
 
@@ -686,17 +686,19 @@ private void lookupTablet(ClientContext context, Text row, boolean retry,
         if ((lastEndRow != null) && (ke.prevEndRow() != null)
             && ke.prevEndRow().equals(lastEndRow)) {
           locToCache = new CachedTablet(new KeyExtent(ke.tableId(), ke.endRow(), lastEndRow),
-              cachedTablet.getTserverLocation(), cachedTablet.getTserverSession(),
-              cachedTablet.getGoal(), cachedTablet.wasHostingRequested());
+              cachedTablet.getServer(), cachedTablet.getGoal(), cachedTablet.wasHostingRequested());
         } else {
           locToCache = cachedTablet;
         }
 
         // save endRow for next iteration
         lastEndRow = locToCache.getExtent().endRow();
 
+        log.trace("Caching tablet location: {}", locToCache);
         updateCache(locToCache, lcSession);
       }
+    } else {
+      log.warn("Metadata tablet not found for row: {}", metadataRow);
     }
 
   }

core/src/main/java/org/apache/accumulo/core/clientImpl/RootClientTabletCache.java

@@ -123,18 +123,17 @@ protected CachedTablet getRootTabletLocation(ClientContext context) {
     }
 
     if (loc == null || loc.getType() != LocationType.CURRENT) {
-      return new CachedTablet(RootTable.EXTENT, Optional.empty(), Optional.empty(),
-          TabletHostingGoal.ALWAYS, false);
+      return new CachedTablet(RootTable.EXTENT, Optional.empty(), TabletHostingGoal.ALWAYS, false);
     }
 
-    String server = loc.getHostPort();
+    String server = loc.getServerInstance().getHostPort();
+    String session = loc.getServerInstance().getSession();
 
-    if (lockChecker.isLockHeld(server, loc.getSession())) {
-      return new CachedTablet(RootTable.EXTENT, server, loc.getSession(), TabletHostingGoal.ALWAYS,
+    if (lockChecker.isLockHeld(server, session)) {
+      return new CachedTablet(RootTable.EXTENT, loc.getServerInstance(), TabletHostingGoal.ALWAYS,
           false);
     } else {
-      return new CachedTablet(RootTable.EXTENT, Optional.empty(), Optional.empty(),
-          TabletHostingGoal.ALWAYS, false);
+      return new CachedTablet(RootTable.EXTENT, Optional.empty(), TabletHostingGoal.ALWAYS, false);
     }
   }
 

core/src/main/java/org/apache/accumulo/core/clientImpl/TableOperationsImpl.java

@@ -1308,7 +1308,7 @@ private void waitForTableStateTransition(TableId tableId, TableState expectedSta
           lastRow = tablet.getExtent().toMetaRow();
 
           if (loc != null) {
-            serverCounts.increment(loc.getHostPortSession(), 1);
+            serverCounts.increment(loc.getServerInstance().getHostPortSessionGroup(), 1);
           }
         }
 

core/src/main/java/org/apache/accumulo/core/conf/Property.java

@@ -30,6 +30,7 @@
 import org.apache.accumulo.core.file.rfile.RFile;
 import org.apache.accumulo.core.iterators.IteratorUtil.IteratorScope;
 import org.apache.accumulo.core.iteratorsImpl.system.DeletingIterator;
+import org.apache.accumulo.core.lock.ServiceLockData.ServiceDescriptor;
 import org.apache.accumulo.core.metadata.MetadataTable;
 import org.apache.accumulo.core.spi.compaction.DefaultCompactionPlanner;
 import org.apache.accumulo.core.spi.compaction.SimpleCompactionDispatcher;
@@ -724,6 +725,11 @@ public enum Property {
       PropertyType.TIMEDURATION,
       "The interval at which the TabletServer will check if on-demand tablets can be unloaded",
       "4.0.0"),
+  TSERV_GROUP_NAME("tserver.group", ServiceDescriptor.DEFAULT_GROUP_NAME, PropertyType.STRING,
+      "Optional group name that will be made available to the "
+          + "TablerServer plugins. Groups can be used to dedicate resources "
+          + " to specific tables (e.g. balancing tablets for table(s) within a group)",
+      "4.0.0"),
 
   // accumulo garbage collector properties
   GC_PREFIX("gc.", null, PropertyType.PREFIX,
@@ -808,6 +814,11 @@ public enum Property {
           + " global setting to take effect. However, you must use the API or the shell"
           + " to change properties in zookeeper that are set on a table.",
       "1.3.5"),
+  TABLE_ASSIGNMENT_GROUP("table.assignment.group", ServiceDescriptor.DEFAULT_GROUP_NAME,
+      PropertyType.STRING,
+      "Tablets for this table will be assigned to TabletServers that have a corresponding"
+          + " tserver.group property value.",
+      "4.0.0"),
   TABLE_ARBITRARY_PROP_PREFIX("table.custom.", null, PropertyType.PREFIX,
       "Prefix to be used for user defined arbitrary properties.", "1.7.0"),
   TABLE_MINC_OUTPUT_DROP_CACHE("table.compaction.minor.output.drop.cache", "false",
@@ -1095,7 +1106,8 @@ public enum Property {
   COMPACTOR_MAX_MESSAGE_SIZE("compactor.message.size.max", "10M", PropertyType.BYTES,
       "The maximum size of a message that can be sent to a tablet server.", "2.1.0"),
   @Experimental
-  COMPACTOR_QUEUE_NAME("compactor.queue", "", PropertyType.STRING,
+  // ELASTICITY_TODO: rename to compactor.group
+  COMPACTOR_QUEUE_NAME("compactor.queue", ServiceDescriptor.DEFAULT_GROUP_NAME, PropertyType.STRING,
       "The queue for which this Compactor will perform compactions", "3.0.0"),
   // CompactionCoordinator properties
   @Experimental

core/src/main/java/org/apache/accumulo/core/lock/ServiceLockData.java

@@ -70,10 +70,6 @@ public static class ServiceDescriptor {
     private final String address;
     private final String group;
 
-    public ServiceDescriptor(UUID uuid, ThriftService service, String address) {
-      this(uuid, service, address, DEFAULT_GROUP_NAME);
-    }
-
     public ServiceDescriptor(UUID uuid, ThriftService service, String address, String group) {
       this.uuid = requireNonNull(uuid);
       this.service = requireNonNull(service);
@@ -159,11 +155,6 @@ public ServiceLockData(UUID uuid, String address, ThriftService service, String
         Collections.singleton(new ServiceDescriptor(uuid, service, address, group)))));
   }
 
-  public ServiceLockData(UUID uuid, String address, ThriftService service) {
-    this(new ServiceDescriptors(
-        new HashSet<>(Collections.singleton(new ServiceDescriptor(uuid, service, address)))));
-  }
-
   public String getAddressString(ThriftService service) {
     ServiceDescriptor sd = services.get(service);
     if (sd == null) {

core/src/main/java/org/apache/accumulo/core/manager/balancer/TabletServerIdImpl.java

@@ -35,9 +35,9 @@ public static TabletServerIdImpl fromThrift(TServerInstance tsi) {
     return (tsi == null) ? null : new TabletServerIdImpl(tsi);
   }
 
-  public TabletServerIdImpl(String host, int port, String session) {
+  public TabletServerIdImpl(String host, int port, String session, String group) {
     requireNonNull(host);
-    this.tServerInstance = new TServerInstance(HostAndPort.fromParts(host, port), session);
+    this.tServerInstance = new TServerInstance(HostAndPort.fromParts(host, port), session, group);
   }
 
   public TabletServerIdImpl(TServerInstance tServerInstance) {
@@ -59,6 +59,11 @@ public String getSession() {
     return tServerInstance.getSession();
   }
 
+  @Override
+  public String getGroup() {
+    return tServerInstance.getGroup();
+  }
+
   @Override
   public int compareTo(TabletServerId o) {
     return tServerInstance.compareTo(((TabletServerIdImpl) o).tServerInstance);
@@ -96,7 +101,7 @@ public static TServerInstance toThrift(TabletServerId tabletServerId) {
     } else {
       return new TServerInstance(
           HostAndPort.fromParts(tabletServerId.getHost(), tabletServerId.getPort()),
-          tabletServerId.getSession());
+          tabletServerId.getSession(), tabletServerId.getGroup());
     }
   }
 }

core/src/main/java/org/apache/accumulo/core/metadata/MetadataCachedTabletObtainer.java

@@ -220,8 +220,7 @@ public List<CachedTablet> lookupTablets(ClientContext context, String tserver,
   }
 
   public static CachedTablets getMetadataLocationEntries(SortedMap<Key,Value> entries) {
-    Text location = null;
-    Text session = null;
+    TServerInstance tsi = null;
     TabletHostingGoal goal = null;
     boolean hostingRequested = false;
 
@@ -238,8 +237,7 @@ public static CachedTablets getMetadataLocationEntries(SortedMap<Key,Value> entr
       Value val = entry.getValue();
 
       if (key.compareRow(lastRowFromKey) != 0) {
-        location = null;
-        session = null;
+        tsi = null;
         goal = null;
         hostingRequested = false;
         key.getRow(lastRowFromKey);
@@ -251,11 +249,10 @@ public static CachedTablets getMetadataLocationEntries(SortedMap<Key,Value> entr
       // interpret the row id as a key extent
       if (colf.equals(CurrentLocationColumnFamily.NAME)
           || colf.equals(FutureLocationColumnFamily.NAME)) {
-        if (location != null) {
+        if (tsi != null) {
           throw new IllegalStateException("Tablet has multiple locations : " + lastRowFromKey);
         }
-        location = new Text(val.toString());
-        session = new Text(colq);
+        tsi = TServerInstance.fromString(val.toString());
       } else if (HostingColumnFamily.GOAL_COLUMN.equals(colf, colq)) {
         goal = TabletHostingGoalUtil.fromValue(val);
       } else if (HostingColumnFamily.REQUESTED_COLUMN.equals(colf, colq)) {
@@ -265,13 +262,12 @@ public static CachedTablets getMetadataLocationEntries(SortedMap<Key,Value> entr
         if (ke.isMeta()) {
           goal = TabletHostingGoal.ALWAYS;
         }
-        if (location != null) {
-          results.add(new CachedTablet(ke, location.toString(), session.toString(), goal,
-              hostingRequested));
+        if (tsi != null) {
+          results.add(new CachedTablet(ke, tsi, goal, hostingRequested));
         } else {
           results.add(new CachedTablet(ke, goal, hostingRequested));
         }
-        location = null;
+        tsi = null;
       }
     }