Remove RoutingTable#version (#112800)

This version was not actually being used anywhere.

Author: nielsbauman

server/src/internalClusterTest/java/org/elasticsearch/cluster/ClusterStateDiffIT.java

@@ -152,7 +152,6 @@ public void testClusterStateDiffSerialization() throws Exception {
                 }
 
                 // Check routing table
-                assertThat(clusterStateFromDiffs.routingTable().version(), equalTo(clusterState.routingTable().version()));
                 assertThat(clusterStateFromDiffs.routingTable().indicesRouting(), equalTo(clusterState.routingTable().indicesRouting()));
 
                 // Check cluster blocks

server/src/main/java/org/elasticsearch/TransportVersions.java

@@ -208,6 +208,7 @@ static TransportVersion def(int id) {
     public static final TransportVersion ESQL_AGGREGATE_EXEC_TRACKS_INTERMEDIATE_ATTRS = def(8_738_00_0);
     public static final TransportVersion CCS_TELEMETRY_STATS = def(8_739_00_0);
     public static final TransportVersion GLOBAL_RETENTION_TELEMETRY = def(8_740_00_0);
+    public static final TransportVersion ROUTING_TABLE_VERSION_REMOVED = def(8_741_00_0);
 
     /*
      * STOP! READ THIS FIRST! No, really,

server/src/main/java/org/elasticsearch/cluster/routing/RoutingTable.java

@@ -8,6 +8,7 @@
 
 package org.elasticsearch.cluster.routing;
 
+import org.elasticsearch.TransportVersions;
 import org.elasticsearch.cluster.Diff;
 import org.elasticsearch.cluster.Diffable;
 import org.elasticsearch.cluster.DiffableUtils;
@@ -45,22 +46,15 @@
  */
 public class RoutingTable implements Iterable<IndexRoutingTable>, Diffable<RoutingTable> {
 
-    public static final RoutingTable EMPTY_ROUTING_TABLE = new RoutingTable(0, ImmutableOpenMap.of());
-
-    private final long version;
+    public static final RoutingTable EMPTY_ROUTING_TABLE = new RoutingTable(ImmutableOpenMap.of());
 
     // index to IndexRoutingTable map
     private final ImmutableOpenMap<String, IndexRoutingTable> indicesRouting;
 
-    private RoutingTable(long version, ImmutableOpenMap<String, IndexRoutingTable> indicesRouting) {
-        this.version = version;
+    private RoutingTable(ImmutableOpenMap<String, IndexRoutingTable> indicesRouting) {
         this.indicesRouting = indicesRouting;
     }
 
-    public RoutingTable withIncrementedVersion() {
-        return new RoutingTable(version + 1, indicesRouting);
-    }
-
     /**
      * Get's the {@link IndexShardRoutingTable} for the given shard id from the given {@link IndexRoutingTable}
      * or throws a {@link ShardNotFoundException} if no shard by the given id is found in the IndexRoutingTable.
@@ -77,15 +71,6 @@ public static IndexShardRoutingTable shardRoutingTable(IndexRoutingTable indexRo
         return indexShard;
     }
 
-    /**
-     * Returns the version of the {@link RoutingTable}.
-     *
-     * @return version of the {@link RoutingTable}
-     */
-    public long version() {
-        return this.version;
-    }
-
     @Override
     public Iterator<IndexRoutingTable> iterator() {
         return indicesRouting.values().iterator();
@@ -331,7 +316,9 @@ public static Diff<RoutingTable> readDiffFrom(StreamInput in) throws IOException
 
     public static RoutingTable readFrom(StreamInput in) throws IOException {
         Builder builder = new Builder();
-        builder.version = in.readLong();
+        if (in.getTransportVersion().before(TransportVersions.ROUTING_TABLE_VERSION_REMOVED)) {
+            in.readLong(); // previously 'version', unused in all applicable versions so any number will do
+        }
         int size = in.readVInt();
         for (int i = 0; i < size; i++) {
             IndexRoutingTable index = IndexRoutingTable.readFrom(in);
@@ -343,46 +330,49 @@ public static RoutingTable readFrom(StreamInput in) throws IOException {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        out.writeLong(version);
+        if (out.getTransportVersion().before(TransportVersions.ROUTING_TABLE_VERSION_REMOVED)) {
+            out.writeLong(0); // previously 'version', unused in all applicable versions so any number will do
+        }
         out.writeCollection(indicesRouting.values());
     }
 
     private static class RoutingTableDiff implements Diff<RoutingTable> {
 
-        private final long version;
-
         private final Diff<ImmutableOpenMap<String, IndexRoutingTable>> indicesRouting;
 
         RoutingTableDiff(RoutingTable before, RoutingTable after) {
-            version = after.version;
             indicesRouting = DiffableUtils.diff(before.indicesRouting, after.indicesRouting, DiffableUtils.getStringKeySerializer());
         }
 
         private static final DiffableUtils.DiffableValueReader<String, IndexRoutingTable> DIFF_VALUE_READER =
             new DiffableUtils.DiffableValueReader<>(IndexRoutingTable::readFrom, IndexRoutingTable::readDiffFrom);
 
         RoutingTableDiff(StreamInput in) throws IOException {
-            version = in.readLong();
+            if (in.getTransportVersion().before(TransportVersions.ROUTING_TABLE_VERSION_REMOVED)) {
+                in.readLong(); // previously 'version', unused in all applicable versions so any number will do
+            }
             indicesRouting = DiffableUtils.readImmutableOpenMapDiff(in, DiffableUtils.getStringKeySerializer(), DIFF_VALUE_READER);
         }
 
         @Override
         public RoutingTable apply(RoutingTable part) {
             final ImmutableOpenMap<String, IndexRoutingTable> updatedRouting = indicesRouting.apply(part.indicesRouting);
-            if (part.version == version && updatedRouting == part.indicesRouting) {
+            if (updatedRouting == part.indicesRouting) {
                 return part;
             }
-            return new RoutingTable(version, updatedRouting);
+            return new RoutingTable(updatedRouting);
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
-            out.writeLong(version);
+            if (out.getTransportVersion().before(TransportVersions.ROUTING_TABLE_VERSION_REMOVED)) {
+                out.writeLong(0); // previously 'version', unused in all applicable versions so any number will do
+            }
             indicesRouting.writeTo(out);
         }
     }
 
-    public static RoutingTable of(long version, RoutingNodes routingNodes) {
+    public static RoutingTable of(RoutingNodes routingNodes) {
         Map<String, IndexRoutingTable.Builder> indexRoutingTableBuilders = new HashMap<>();
         for (RoutingNode routingNode : routingNodes) {
             for (ShardRouting shardRoutingEntry : routingNode) {
@@ -404,7 +394,7 @@ public static RoutingTable of(long version, RoutingNodes routingNodes) {
             IndexRoutingTable indexRoutingTable = indexBuilder.build();
             indicesRouting.put(indexRoutingTable.getIndex().getName(), indexRoutingTable);
         }
-        return new RoutingTable(version, indicesRouting.build());
+        return new RoutingTable(indicesRouting.build());
     }
 
     public static Builder builder() {
@@ -429,7 +419,6 @@ public static Builder builder(ShardRoutingRoleStrategy shardRoutingRoleStrategy,
     public static class Builder {
 
         private final ShardRoutingRoleStrategy shardRoutingRoleStrategy;
-        private long version;
         private ImmutableOpenMap.Builder<String, IndexRoutingTable> indicesRouting;
 
         public Builder() {
@@ -447,7 +436,6 @@ public Builder(ShardRoutingRoleStrategy shardRoutingRoleStrategy) {
 
         public Builder(ShardRoutingRoleStrategy shardRoutingRoleStrategy, RoutingTable routingTable) {
             this.shardRoutingRoleStrategy = shardRoutingRoleStrategy;
-            this.version = routingTable.version;
             this.indicesRouting = ImmutableOpenMap.builder(routingTable.indicesRouting);
         }
 
@@ -591,16 +579,6 @@ public Builder remove(String index) {
             return this;
         }
 
-        public Builder version(long version) {
-            this.version = version;
-            return this;
-        }
-
-        public Builder incrementVersion() {
-            this.version++;
-            return this;
-        }
-
         /**
          * Builds the routing table. Note that once this is called the builder
          * must be thrown away. If you need to build a new RoutingTable as a
@@ -610,15 +588,15 @@ public RoutingTable build() {
             if (indicesRouting == null) {
                 throw new IllegalStateException("once build is called the builder cannot be reused");
             }
-            RoutingTable table = new RoutingTable(version, indicesRouting.build());
+            RoutingTable table = new RoutingTable(indicesRouting.build());
             indicesRouting = null;
             return table;
         }
     }
 
     @Override
     public String toString() {
-        StringBuilder sb = new StringBuilder("routing_table (version ").append(version).append("):\n");
+        StringBuilder sb = new StringBuilder("routing_table:\n");
         for (IndexRoutingTable entry : indicesRouting.values()) {
             sb.append(entry.prettyPrint()).append('\n');
         }

server/src/main/java/org/elasticsearch/cluster/routing/allocation/AllocationService.java

@@ -159,7 +159,7 @@ public ClusterState applyStartedShards(ClusterState clusterState, List<ShardRout
     private static ClusterState buildResultAndLogHealthChange(ClusterState oldState, RoutingAllocation allocation, String reason) {
         final RoutingTable oldRoutingTable = oldState.routingTable();
         final RoutingNodes newRoutingNodes = allocation.routingNodes();
-        final RoutingTable newRoutingTable = RoutingTable.of(oldRoutingTable.version(), newRoutingNodes);
+        final RoutingTable newRoutingTable = RoutingTable.of(newRoutingNodes);
         final Metadata newMetadata = allocation.updateMetadataWithRoutingChanges(newRoutingTable);
         assert newRoutingTable.validate(newMetadata); // validates the routing table is coherent with the cluster state metadata
 

server/src/main/java/org/elasticsearch/cluster/routing/allocation/RoutingAllocation.java

@@ -429,11 +429,7 @@ public void setSimulatedClusterInfo(ClusterInfo clusterInfo) {
     public RoutingAllocation immutableClone() {
         return new RoutingAllocation(
             deciders,
-            routingNodesChanged()
-                ? ClusterState.builder(clusterState)
-                    .routingTable(RoutingTable.of(clusterState.routingTable().version(), routingNodes))
-                    .build()
-                : clusterState,
+            routingNodesChanged() ? ClusterState.builder(clusterState).routingTable(RoutingTable.of(routingNodes)).build() : clusterState,
             clusterInfo,
             shardSizeInfo,
             currentNanoTime

server/src/main/java/org/elasticsearch/cluster/service/MasterService.java

@@ -505,9 +505,6 @@ private ClusterState patchVersions(ClusterState previousClusterState, ClusterSta
         if (previousClusterState != newClusterState) {
             // only the master controls the version numbers
             Builder builder = incrementVersion(newClusterState);
-            if (previousClusterState.routingTable() != newClusterState.routingTable()) {
-                builder.routingTable(newClusterState.routingTable().withIncrementedVersion());
-            }
             if (previousClusterState.metadata() != newClusterState.metadata()) {
                 builder.metadata(newClusterState.metadata().withIncrementedVersion());
             }
@@ -535,10 +532,6 @@ private static boolean versionNumbersPreserved(ClusterState oldState, ClusterSta
         if (oldState.metadata().version() != newState.metadata().version()) {
             return false;
         }
-        if (oldState.routingTable().version() != newState.routingTable().version()) {
-            // GatewayService is special and for odd legacy reasons gets to do this:
-            return oldState.clusterRecovered() == false && newState.clusterRecovered() && newState.routingTable().version() == 0;
-        }
         return true;
     }
 

server/src/main/java/org/elasticsearch/gateway/ClusterStateUpdaters.java

@@ -98,8 +98,6 @@ static ClusterState updateRoutingTable(final ClusterState state, ShardRoutingRol
         for (final IndexMetadata indexMetadata : state.metadata().indices().values()) {
             routingTableBuilder.addAsRecovery(indexMetadata);
         }
-        // start with 0 based versions for routing table
-        routingTableBuilder.version(0);
         return ClusterState.builder(state).routingTable(routingTableBuilder.build()).build();
     }
 

server/src/test/java/org/elasticsearch/cluster/ClusterChangedEventTests.java

@@ -343,7 +343,7 @@ private static ClusterState createState(final int numNodes, final boolean isLoca
         return ClusterState.builder(TEST_CLUSTER_NAME)
             .nodes(createDiscoveryNodes(numNodes, isLocalMaster))
             .metadata(metadata)
-            .routingTable(createRoutingTable(1, metadata))
+            .routingTable(createRoutingTable(metadata))
             .build();
     }
 
@@ -498,8 +498,8 @@ private static IndexMetadata createIndexMetadata(final Index index, final long v
     }
 
     // Create the routing table for a cluster state.
-    private static RoutingTable createRoutingTable(final long version, final Metadata metadata) {
-        final RoutingTable.Builder builder = RoutingTable.builder(TestShardRoutingRoleStrategies.DEFAULT_ROLE_ONLY).version(version);
+    private static RoutingTable createRoutingTable(final Metadata metadata) {
+        final RoutingTable.Builder builder = RoutingTable.builder(TestShardRoutingRoleStrategies.DEFAULT_ROLE_ONLY);
         for (IndexMetadata indexMetadata : metadata.indices().values()) {
             builder.addAsNew(indexMetadata);
         }

server/src/test/java/org/elasticsearch/cluster/routing/PrimaryTermsTests.java

@@ -119,9 +119,7 @@ private void applyRerouteResult(ClusterState newClusterState) {
         ClusterState previousClusterState = this.clusterState;
         ClusterState.Builder builder = ClusterState.builder(newClusterState).incrementVersion();
         if (previousClusterState.routingTable() != newClusterState.routingTable()) {
-            builder.routingTable(
-                RoutingTable.builder(newClusterState.routingTable()).version(newClusterState.routingTable().version() + 1).build()
-            );
+            builder.routingTable(RoutingTable.builder(newClusterState.routingTable()).build());
         }
         if (previousClusterState.metadata() != newClusterState.metadata()) {
             builder.metadata(Metadata.builder(newClusterState.metadata()).version(newClusterState.metadata().version() + 1));

server/src/test/java/org/elasticsearch/cluster/routing/RoutingTableTests.java

@@ -497,7 +497,7 @@ public void testRemoveReplicasInRightOrder() {
     public void testRoutingNodesRoundtrip() {
         final RoutingTable originalTable = clusterState.getRoutingTable();
         final RoutingNodes routingNodes = clusterState.getRoutingNodes();
-        final RoutingTable fromNodes = RoutingTable.of(originalTable.version(), routingNodes);
+        final RoutingTable fromNodes = RoutingTable.of(routingNodes);
         // we don't have an equals implementation for the routing table so we assert equality by checking for a noop diff
         final Diff<RoutingTable> routingTableDiff = fromNodes.diff(originalTable);
         assertSame(originalTable, routingTableDiff.apply(originalTable));