Remove a whole host of references to unsupported transport versions

modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java

@@ -206,11 +206,7 @@ public InternalAutoDateHistogram(StreamInput in) throws IOException {
         format = in.readNamedWriteable(DocValueFormat.class);
         buckets = in.readCollectionAsList(stream -> Bucket.readFrom(stream, format));
         this.targetBuckets = in.readVInt();
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_3_0)) {
-            bucketInnerInterval = in.readVLong();
-        } else {
-            bucketInnerInterval = 1; // Calculated on merge.
-        }
+        bucketInnerInterval = in.readVLong();
         // we changed the order format in 8.13 for partial reduce, therefore we need to order them to perform merge sort
         if (in.getTransportVersion().between(TransportVersions.V_8_13_0, TransportVersions.V_8_14_0)) {
             // list is mutable by #readCollectionAsList contract
@@ -224,9 +220,7 @@ protected void doWriteTo(StreamOutput out) throws IOException {
         out.writeNamedWriteable(format);
         out.writeCollection(buckets);
         out.writeVInt(targetBuckets);
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_3_0)) {
-            out.writeVLong(bucketInnerInterval);
-        }
+        out.writeVLong(bucketInnerInterval);
     }
 
     long getBucketInnerInterval() {

modules/ingest-geoip/src/main/java/org/elasticsearch/ingest/geoip/direct/DatabaseConfiguration.java

@@ -9,7 +9,6 @@
 
 package org.elasticsearch.ingest.geoip.direct;
 
-import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.ActionRequestValidationException;
 import org.elasticsearch.cluster.metadata.MetadataCreateIndexService;
 import org.elasticsearch.common.Strings;
@@ -138,12 +137,7 @@ public DatabaseConfiguration(StreamInput in) throws IOException {
     }
 
     private static Provider readProvider(StreamInput in) throws IOException {
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_16_0)) {
-            return in.readNamedWriteable(Provider.class);
-        } else {
-            // prior to the above version, everything was always a maxmind, so this half of the if is logical
-            return new Maxmind(in.readString());
-        }
+        return in.readNamedWriteable(Provider.class);
     }
 
     public static DatabaseConfiguration parse(XContentParser parser, String id) {
@@ -154,15 +148,7 @@ public static DatabaseConfiguration parse(XContentParser parser, String id) {
     public void writeTo(StreamOutput out) throws IOException {
         out.writeString(id);
         out.writeString(name);
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_16_0)) {
-            out.writeNamedWriteable(provider);
-        } else {
-            if (provider instanceof Maxmind maxmind) {
-                out.writeString(maxmind.accountId);
-            } else {
-                assert false : "non-maxmind DatabaseConfiguration.Provider [" + provider.getWriteableName() + "]";
-            }
-        }
+        out.writeNamedWriteable(provider);
     }
 
     @Override

modules/ingest-geoip/src/main/java/org/elasticsearch/ingest/geoip/stats/GeoIpStatsAction.java

@@ -9,7 +9,6 @@
 
 package org.elasticsearch.ingest.geoip.stats;
 
-import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.ActionType;
 import org.elasticsearch.action.FailedNodeException;
 import org.elasticsearch.action.support.nodes.BaseNodeResponse;
@@ -167,11 +166,7 @@ public static class NodeResponse extends BaseNodeResponse {
         protected NodeResponse(StreamInput in) throws IOException {
             super(in);
             downloaderStats = in.readBoolean() ? new GeoIpDownloaderStats(in) : null;
-            if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_14_0)) {
-                cacheStats = in.readBoolean() ? new CacheStats(in) : null;
-            } else {
-                cacheStats = null;
-            }
+            cacheStats = in.readBoolean() ? new CacheStats(in) : null;
             databases = in.readCollectionAsImmutableSet(StreamInput::readString);
             filesInTemp = in.readCollectionAsImmutableSet(StreamInput::readString);
             configDatabases = in.readCollectionAsImmutableSet(StreamInput::readString);
@@ -216,11 +211,9 @@ public void writeTo(StreamOutput out) throws IOException {
             if (downloaderStats != null) {
                 downloaderStats.writeTo(out);
             }
-            if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_14_0)) {
-                out.writeBoolean(cacheStats != null);
-                if (cacheStats != null) {
-                    cacheStats.writeTo(out);
-                }
+            out.writeBoolean(cacheStats != null);
+            if (cacheStats != null) {
+                cacheStats.writeTo(out);
             }
             out.writeStringCollection(databases);
             out.writeStringCollection(filesInTemp);

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

@@ -220,21 +220,9 @@ public static Build readBuild(StreamInput in) throws IOException {
         final String minWireVersion;
         final String minIndexVersion;
         final String displayString;
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_12_0)) {
-            version = in.readString();
-            qualifier = in.readOptionalString();
-            snapshot = in.readBoolean();
-        } else {
-            snapshot = in.readBoolean();
-            String rawVersion = in.readString();
-            // need to separate out qualifiers from older nodes
-            var versionMatcher = qualfiedVersionRegex.matcher(rawVersion);
-            if (versionMatcher.matches() == false) {
-                throw new IllegalStateException(String.format(Locale.ROOT, "Malformed elasticsearch compile version: %s", rawVersion));
-            }
-            version = versionMatcher.group(1);
-            qualifier = versionMatcher.group(2);
-        }
+        version = in.readString();
+        qualifier = in.readOptionalString();
+        snapshot = in.readBoolean();
         if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_10_X)) {
             minWireVersion = in.readString();
             minIndexVersion = in.readString();
@@ -258,14 +246,9 @@ public static void writeBuild(Build build, StreamOutput out) throws IOException
         out.writeString(build.type().displayName());
         out.writeString(build.hash());
         out.writeString(build.date());
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_12_0)) {
-            out.writeString(build.version());
-            out.writeOptionalString(build.qualifier());
-            out.writeBoolean(build.isSnapshot());
-        } else {
-            out.writeBoolean(build.isSnapshot());
-            out.writeString(build.qualifiedVersion());
-        }
+        out.writeString(build.version());
+        out.writeOptionalString(build.qualifier());
+        out.writeBoolean(build.isSnapshot());
         if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_10_X)) {
             out.writeString(build.minWireCompatVersion());
             out.writeString(build.minIndexCompatVersion());

server/src/main/java/org/elasticsearch/action/admin/cluster/allocation/TransportGetAllocationStatsAction.java

@@ -93,11 +93,6 @@ public TransportGetAllocationStatsAction(
 
     @Override
     protected void doExecute(Task task, Request request, ActionListener<Response> listener) {
-        if (clusterService.state().getMinTransportVersion().before(TransportVersions.V_8_14_0)) {
-            // The action is not available before ALLOCATION_STATS
-            listener.onResponse(new Response(Map.of(), null));
-            return;
-        }
         super.doExecute(task, request, listener);
     }
 
@@ -144,9 +139,7 @@ public Request(StreamInput in) throws IOException {
         public void writeTo(StreamOutput out) throws IOException {
             assert out.getTransportVersion().onOrAfter(TransportVersions.V_8_14_0);
             super.writeTo(out);
-            if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_16_0)) {
-                out.writeEnumSet(metrics);
-            }
+            out.writeEnumSet(metrics);
         }
 
         public EnumSet<Metric> metrics() {
@@ -177,21 +170,13 @@ public Response(Map<String, NodeAllocationStats> nodeAllocationStats, DiskThresh
 
         public Response(StreamInput in) throws IOException {
             this.nodeAllocationStats = in.readImmutableMap(StreamInput::readString, NodeAllocationStats::new);
-            if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_15_0)) {
-                this.diskThresholdSettings = in.readOptionalWriteable(DiskThresholdSettings::readFrom);
-            } else {
-                this.diskThresholdSettings = null;
-            }
+            this.diskThresholdSettings = in.readOptionalWriteable(DiskThresholdSettings::readFrom);
         }
 
         @Override
         public void writeTo(StreamOutput out) throws IOException {
             out.writeMap(nodeAllocationStats, StreamOutput::writeString, StreamOutput::writeWriteable);
-            if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_15_0)) {
-                out.writeOptionalWriteable(diskThresholdSettings);
-            } else {
-                assert diskThresholdSettings == null;
-            }
+            out.writeOptionalWriteable(diskThresholdSettings);
         }
 
         public Map<String, NodeAllocationStats> getNodeAllocationStats() {

server/src/main/java/org/elasticsearch/action/admin/cluster/node/hotthreads/NodeHotThreads.java

@@ -9,10 +9,8 @@
 
 package org.elasticsearch.action.admin.cluster.node.hotthreads;
 
-import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.support.nodes.BaseNodeResponse;
 import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.ReleasableBytesReference;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
@@ -28,11 +26,7 @@ public class NodeHotThreads extends BaseNodeResponse {
 
     NodeHotThreads(StreamInput in) throws IOException {
         super(in);
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_13_0)) {
-            bytes = in.readReleasableBytesReference();
-        } else {
-            bytes = ReleasableBytesReference.wrap(new BytesArray(in.readString().getBytes(StandardCharsets.UTF_8)));
-        }
+        bytes = in.readReleasableBytesReference();
     }
 
     public NodeHotThreads(DiscoveryNode node, ReleasableBytesReference hotThreadsUtf8Bytes) {
@@ -57,11 +51,7 @@ public java.io.Reader getHotThreadsReader() {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_13_0)) {
-            out.writeBytesReference(bytes);
-        } else {
-            out.writeString(bytes.utf8ToString());
-        }
+        out.writeBytesReference(bytes);
     }
 
     @Override

server/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodeInfo.java

@@ -12,7 +12,6 @@
 import org.elasticsearch.Build;
 import org.elasticsearch.TransportVersion;
 import org.elasticsearch.TransportVersions;
-import org.elasticsearch.Version;
 import org.elasticsearch.action.support.nodes.BaseNodeResponse;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.version.CompatibilityVersions;
@@ -64,33 +63,14 @@ public class NodeInfo extends BaseNodeResponse {
 
     public NodeInfo(StreamInput in) throws IOException {
         super(in);
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_12_0)) {
-            version = in.readString();
-            if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_16_1)) {
-                compatibilityVersions = CompatibilityVersions.readVersion(in);
-            } else {
-                compatibilityVersions = new CompatibilityVersions(TransportVersion.readVersion(in), Map.of()); // unknown mappings versions
-            }
-            indexVersion = IndexVersion.readVersion(in);
+        version = in.readString();
+        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_16_1)) {
+            compatibilityVersions = CompatibilityVersions.readVersion(in);
         } else {
-            Version legacyVersion = Version.readVersion(in);
-            version = legacyVersion.toString();
-            if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_8_0)) {
-                compatibilityVersions = new CompatibilityVersions(TransportVersion.readVersion(in), Map.of()); // unknown mappings versions
-            } else {
-                compatibilityVersions = new CompatibilityVersions(TransportVersion.fromId(legacyVersion.id), Map.of());
-            }
-            if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_11_X)) {
-                indexVersion = IndexVersion.readVersion(in);
-            } else {
-                indexVersion = IndexVersion.fromId(legacyVersion.id);
-            }
-        }
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_11_X)) {
-            componentVersions = in.readImmutableMap(StreamInput::readString, StreamInput::readVInt);
-        } else {
-            componentVersions = Map.of();
+            compatibilityVersions = new CompatibilityVersions(TransportVersion.readVersion(in), Map.of()); // unknown mappings versions
         }
+        indexVersion = IndexVersion.readVersion(in);
+        componentVersions = in.readImmutableMap(StreamInput::readString, StreamInput::readVInt);
         build = Build.readBuild(in);
         if (in.readBoolean()) {
             totalIndexingBuffer = ByteSizeValue.ofBytes(in.readLong());
@@ -111,9 +91,7 @@ public NodeInfo(StreamInput in) throws IOException {
         addInfoIfNonNull(PluginsAndModules.class, in.readOptionalWriteable(PluginsAndModules::new));
         addInfoIfNonNull(IngestInfo.class, in.readOptionalWriteable(IngestInfo::new));
         addInfoIfNonNull(AggregationInfo.class, in.readOptionalWriteable(AggregationInfo::new));
-        if (in.getTransportVersion().onOrAfter(TransportVersions.V_8_8_0)) {
-            addInfoIfNonNull(RemoteClusterServerInfo.class, in.readOptionalWriteable(RemoteClusterServerInfo::new));
-        }
+        addInfoIfNonNull(RemoteClusterServerInfo.class, in.readOptionalWriteable(RemoteClusterServerInfo::new));
     }
 
     public NodeInfo(
@@ -246,20 +224,10 @@ private <T extends ReportingService.Info> void addInfoIfNonNull(Class<T> clazz,
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_12_0)) {
-            out.writeString(version);
-        } else {
-            Version.writeVersion(Version.fromString(version), out);
-        }
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_16_1)) {
-            compatibilityVersions.writeTo(out);
-        } else if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_8_0)) {
-            TransportVersion.writeVersion(compatibilityVersions.transportVersion(), out);
-        }
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_11_X)) {
-            IndexVersion.writeVersion(indexVersion, out);
-            out.writeMap(componentVersions, StreamOutput::writeString, StreamOutput::writeVInt);
-        }
+        out.writeString(version);
+        compatibilityVersions.writeTo(out);
+        IndexVersion.writeVersion(indexVersion, out);
+        out.writeMap(componentVersions, StreamOutput::writeString, StreamOutput::writeVInt);
         Build.writeBuild(build, out);
         if (totalIndexingBuffer == null) {
             out.writeBoolean(false);
@@ -282,8 +250,6 @@ public void writeTo(StreamOutput out) throws IOException {
         out.writeOptionalWriteable(getInfo(PluginsAndModules.class));
         out.writeOptionalWriteable(getInfo(IngestInfo.class));
         out.writeOptionalWriteable(getInfo(AggregationInfo.class));
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_8_0)) {
-            out.writeOptionalWriteable(getInfo(RemoteClusterServerInfo.class));
-        }
+        out.writeOptionalWriteable(getInfo(RemoteClusterServerInfo.class));
     }
 }

server/src/main/java/org/elasticsearch/action/admin/cluster/node/info/PluginsAndModules.java

@@ -9,7 +9,6 @@
 
 package org.elasticsearch.action.admin.cluster.node.info;
 
-import org.elasticsearch.TransportVersions;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.node.ReportingService;
@@ -42,11 +41,7 @@ public PluginsAndModules(StreamInput in) throws IOException {
 
     @Override
     public void writeTo(StreamOutput out) throws IOException {
-        if (out.getTransportVersion().onOrAfter(TransportVersions.V_8_3_0)) {
-            out.writeCollection(plugins);
-        } else {
-            out.writeCollection(plugins.stream().map(PluginRuntimeInfo::descriptor).toList());
-        }
+        out.writeCollection(plugins);
         out.writeCollection(modules);
     }
 

server/src/main/java/org/elasticsearch/action/admin/cluster/node/reload/NodesReloadSecureSettingsRequest.java

@@ -9,10 +9,7 @@
 
 package org.elasticsearch.action.admin.cluster.node.reload;
 
-import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.support.nodes.BaseNodesRequest;
-import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.io.stream.StreamInput;
@@ -23,7 +20,6 @@
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.RefCounted;
 import org.elasticsearch.core.Releasables;
-import org.elasticsearch.tasks.TaskId;
 import org.elasticsearch.transport.AbstractTransportRequest;
 import org.elasticsearch.transport.LeakTracker;
 
@@ -92,13 +88,6 @@ public static class NodeRequest extends AbstractTransportRequest {
         NodeRequest(StreamInput in) throws IOException {
             super(in);
 
-            if (in.getTransportVersion().before(TransportVersions.V_8_13_0)) {
-                TaskId.readFromStream(in);
-                in.readStringArray();
-                in.readOptionalArray(DiscoveryNode::new, DiscoveryNode[]::new);
-                in.readOptionalTimeValue();
-            }
-
             final BytesReference bytesRef = in.readOptionalBytesReference();
             if (bytesRef != null) {
                 byte[] bytes = BytesReference.toBytes(bytesRef);
@@ -126,13 +115,6 @@ public void writeTo(StreamOutput out) throws IOException {
             assert hasReferences();
             super.writeTo(out);
 
-            if (out.getTransportVersion().before(TransportVersions.V_8_13_0)) {
-                TaskId.EMPTY_TASK_ID.writeTo(out);
-                out.writeStringArray(Strings.EMPTY_ARRAY);
-                out.writeOptionalArray(StreamOutput::writeWriteable, null);
-                out.writeOptionalTimeValue(null);
-            }
-
             if (this.secureSettingsPassword == null) {
                 out.writeOptionalBytesReference(null);
             } else {

server/src/main/java/org/elasticsearch/action/admin/cluster/node/shutdown/NodesRemovalPrevalidation.java

@@ -156,9 +156,6 @@ public void writeTo(StreamOutput out) throws IOException {
         }
 
         public static Result readFrom(final StreamInput in) throws IOException {
-            if (in.getTransportVersion().before(TransportVersions.V_8_7_0)) {
-                return new Result(in.readBoolean(), null, in.readString());
-            }
             return new Result(in.readBoolean(), Reason.readFrom(in), in.readString());
         }