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 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
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 * specific language governing permissions and limitations
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package org.elasticsearch.cluster.serialization;

import org.elasticsearch.Version;
import org.elasticsearch.cluster.ClusterModule;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.Diff;
import org.elasticsearch.cluster.ESAllocationTestCase;
import org.elasticsearch.cluster.RestoreInProgress;
import org.elasticsearch.cluster.SnapshotDeletionsInProgress;
import org.elasticsearch.cluster.metadata.IndexMetaData;
import org.elasticsearch.cluster.metadata.MetaData;
import org.elasticsearch.cluster.node.DiscoveryNodes;
import org.elasticsearch.cluster.routing.RoutingTable;
import org.elasticsearch.cluster.routing.allocation.AllocationService;
import org.elasticsearch.common.UUIDs;
import org.elasticsearch.common.collect.ImmutableOpenMap;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.snapshots.Snapshot;
import org.elasticsearch.snapshots.SnapshotId;

import java.util.Collections;

import static org.elasticsearch.test.VersionUtils.randomVersionBetween;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.notNullValue;
import static org.hamcrest.Matchers.nullValue;

public class ClusterSerializationTests extends ESAllocationTestCase {

    public void testClusterStateSerialization() throws Exception {
        MetaData metaData = MetaData.builder()
                .put(IndexMetaData.builder("test").settings(settings(Version.CURRENT)).numberOfShards(10).numberOfReplicas(1))
                .build();

        RoutingTable routingTable = RoutingTable.builder()
                .addAsNew(metaData.index("test"))
                .build();

        DiscoveryNodes nodes = DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")).add(newNode("node3")).localNodeId("node1").masterNodeId("node2").build();

        ClusterState clusterState = ClusterState.builder(new ClusterName("clusterName1")).nodes(nodes).metaData(metaData).routingTable(routingTable).build();

        AllocationService strategy = createAllocationService();
        clusterState = ClusterState.builder(clusterState).routingTable(strategy.reroute(clusterState, "reroute").routingTable()).build();

        ClusterState serializedClusterState = ClusterState.Builder.fromBytes(ClusterState.Builder.toBytes(clusterState), newNode("node1"),
            new NamedWriteableRegistry(ClusterModule.getNamedWriteables()));

        assertThat(serializedClusterState.getClusterName().value(), equalTo(clusterState.getClusterName().value()));

        assertThat(serializedClusterState.routingTable().toString(), equalTo(clusterState.routingTable().toString()));
    }

    public void testRoutingTableSerialization() throws Exception {
        MetaData metaData = MetaData.builder()
                .put(IndexMetaData.builder("test").settings(settings(Version.CURRENT)).numberOfShards(10).numberOfReplicas(1))
                .build();

        RoutingTable routingTable = RoutingTable.builder()
                .addAsNew(metaData.index("test"))
                .build();

        DiscoveryNodes nodes = DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")).add(newNode("node3")).build();

        ClusterState clusterState = ClusterState.builder(ClusterName.CLUSTER_NAME_SETTING.getDefault(Settings.EMPTY)).nodes(nodes)
            .metaData(metaData).routingTable(routingTable).build();

        AllocationService strategy = createAllocationService();
        RoutingTable source = strategy.reroute(clusterState, "reroute").routingTable();

        BytesStreamOutput outStream = new BytesStreamOutput();
        source.writeTo(outStream);
        StreamInput inStream = outStream.bytes().streamInput();
        RoutingTable target = RoutingTable.readFrom(inStream);

        assertThat(target.toString(), equalTo(source.toString()));
    }

    public void testSnapshotDeletionsInProgressSerialization() throws Exception {

        boolean includeRestore = randomBoolean();

        ClusterState.Builder builder = ClusterState.builder(ClusterState.EMPTY_STATE)
            .putCustom(SnapshotDeletionsInProgress.TYPE,
                SnapshotDeletionsInProgress.newInstance(
                    new SnapshotDeletionsInProgress.Entry(
                        new Snapshot("repo1", new SnapshotId("snap1", UUIDs.randomBase64UUID())),
                        randomNonNegativeLong(), randomNonNegativeLong())
                ));
        if (includeRestore) {
            builder.putCustom(RestoreInProgress.TYPE,
                new RestoreInProgress(
                    new RestoreInProgress.Entry(
                        new Snapshot("repo2", new SnapshotId("snap2", UUIDs.randomBase64UUID())),
                        RestoreInProgress.State.STARTED,
                        Collections.singletonList("index_name"),
                        ImmutableOpenMap.of()
                    )
                ));
        }

        ClusterState clusterState = builder.incrementVersion().build();

        Diff<ClusterState> diffs = clusterState.diff(ClusterState.EMPTY_STATE);

        // serialize with current version
        BytesStreamOutput outStream = new BytesStreamOutput();
        diffs.writeTo(outStream);
        StreamInput inStream = outStream.bytes().streamInput();
        inStream = new NamedWriteableAwareStreamInput(inStream, new NamedWriteableRegistry(ClusterModule.getNamedWriteables()));
        Diff<ClusterState> serializedDiffs = ClusterState.readDiffFrom(inStream, clusterState.nodes().getLocalNode());
        ClusterState stateAfterDiffs = serializedDiffs.apply(ClusterState.EMPTY_STATE);
        assertThat(stateAfterDiffs.custom(RestoreInProgress.TYPE), includeRestore ? notNullValue() : nullValue());
        assertThat(stateAfterDiffs.custom(SnapshotDeletionsInProgress.TYPE), notNullValue());

        // serialize with old version
        outStream = new BytesStreamOutput();
        outStream.setVersion(Version.CURRENT.minimumIndexCompatibilityVersion());
        diffs.writeTo(outStream);
        inStream = outStream.bytes().streamInput();
        inStream = new NamedWriteableAwareStreamInput(inStream, new NamedWriteableRegistry(ClusterModule.getNamedWriteables()));
        serializedDiffs = ClusterState.readDiffFrom(inStream, clusterState.nodes().getLocalNode());
        stateAfterDiffs = serializedDiffs.apply(ClusterState.EMPTY_STATE);
        assertThat(stateAfterDiffs.custom(RestoreInProgress.TYPE), includeRestore ? notNullValue() : nullValue());
        assertThat(stateAfterDiffs.custom(SnapshotDeletionsInProgress.TYPE), nullValue());

        // remove the custom and try serializing again with old version
        clusterState = ClusterState.builder(clusterState).removeCustom(SnapshotDeletionsInProgress.TYPE).incrementVersion().build();
        outStream = new BytesStreamOutput();
        diffs.writeTo(outStream);
        inStream = outStream.bytes().streamInput();
        inStream = new NamedWriteableAwareStreamInput(inStream, new NamedWriteableRegistry(ClusterModule.getNamedWriteables()));
        serializedDiffs = ClusterState.readDiffFrom(inStream, clusterState.nodes().getLocalNode());
        stateAfterDiffs = serializedDiffs.apply(stateAfterDiffs);
        assertThat(stateAfterDiffs.custom(RestoreInProgress.TYPE), includeRestore ? notNullValue() : nullValue());
        assertThat(stateAfterDiffs.custom(SnapshotDeletionsInProgress.TYPE), nullValue());
    }

}

@@ -7132,32 +7132,85 @@
 .streamInput();%0A
+        inStream.setVersion(outStream.getVersion());%0A
         inStream

Use correct StreamInput version to deserialize in testSnapshotDeletionsInProgressSerialization