Remove the failures field from snapshot responses

Failure handling for snapshots was made stricter in #107191 (8.15),
so this field is always empty since then. Clients don't need to check it
anymore for failure handling, we can remove it from API responses in 9.0

Author: arteam

server/src/internalClusterTest/java/org/elasticsearch/snapshots/SnapshotStatusApisIT.java

@@ -316,7 +316,6 @@ public void testGetSnapshotsNoRepos() {
             .get();
 
         assertTrue(getSnapshotsResponse.getSnapshots().isEmpty());
-        assertTrue(getSnapshotsResponse.getFailures().isEmpty());
     }
 
     public void testGetSnapshotsMultipleRepos() throws Exception {

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/get/GetSnapshotsResponse.java

@@ -17,12 +17,10 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ChunkedToXContentObject;
 import org.elasticsearch.core.Nullable;
-import org.elasticsearch.core.UpdateForV9;
 import org.elasticsearch.snapshots.SnapshotInfo;
 import org.elasticsearch.xcontent.ToXContent;
 
 import java.io.IOException;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -35,9 +33,6 @@ public class GetSnapshotsResponse extends ActionResponse implements ChunkedToXCo
 
     private final List<SnapshotInfo> snapshots;
 
-    @UpdateForV9(owner = UpdateForV9.Owner.DISTRIBUTED_COORDINATION) // always empty, can be dropped
-    private final Map<String, ElasticsearchException> failures;
-
     @Nullable
     private final String next;
 
@@ -53,15 +48,15 @@ public GetSnapshotsResponse(
         final int remaining
     ) {
         this.snapshots = List.copyOf(snapshots);
-        this.failures = failures == null ? Map.of() : Map.copyOf(failures);
         this.next = next;
         this.total = total;
         this.remaining = remaining;
     }
 
     public GetSnapshotsResponse(StreamInput in) throws IOException {
         this.snapshots = in.readCollectionAsImmutableList(SnapshotInfo::readFrom);
-        this.failures = Collections.unmodifiableMap(in.readMap(StreamInput::readException));
+        // TODO Skip when we have V9 in TransportVersions
+        in.readMap(StreamInput::readException);
         this.next = in.readOptionalString();
         this.total = in.readVInt();
         this.remaining = in.readVInt();
@@ -76,25 +71,11 @@ public List<SnapshotInfo> getSnapshots() {
         return snapshots;
     }
 
-    /**
-     * Returns a map of repository name to {@link ElasticsearchException} for each unsuccessful response.
-     */
-    public Map<String, ElasticsearchException> getFailures() {
-        return failures;
-    }
-
     @Nullable
     public String next() {
         return next;
     }
 
-    /**
-     * Returns true if there is at least one failed response.
-     */
-    public boolean isFailed() {
-        return failures.isEmpty() == false;
-    }
-
     public int totalCount() {
         return total;
     }
@@ -106,7 +87,8 @@ public int remaining() {
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeCollection(snapshots);
-        out.writeMap(failures, StreamOutput::writeException);
+        // TODO Skip when we have V9 in TransportVersions
+        out.writeMap(Map.of(), StreamOutput::writeException);
         out.writeOptionalString(next);
         out.writeVInt(total);
         out.writeVInt(remaining);
@@ -120,18 +102,6 @@ public Iterator<ToXContent> toXContentChunked(ToXContent.Params params) {
             return b;
         }), Iterators.map(getSnapshots().iterator(), snapshotInfo -> snapshotInfo::toXContentExternal), Iterators.single((b, p) -> {
             b.endArray();
-            if (failures.isEmpty() == false) {
-                b.startObject("failures");
-                for (Map.Entry<String, ElasticsearchException> error : failures.entrySet()) {
-                    b.field(error.getKey(), (bb, pa) -> {
-                        bb.startObject();
-                        error.getValue().toXContent(bb, pa);
-                        bb.endObject();
-                        return bb;
-                    });
-                }
-                b.endObject();
-            }
             if (next != null) {
                 b.field("next", next);
             }
@@ -151,12 +121,12 @@ public boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         GetSnapshotsResponse that = (GetSnapshotsResponse) o;
-        return Objects.equals(snapshots, that.snapshots) && Objects.equals(failures, that.failures) && Objects.equals(next, that.next);
+        return Objects.equals(snapshots, that.snapshots) && Objects.equals(next, that.next);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(snapshots, failures, next);
+        return Objects.hash(snapshots, next);
     }
 
     @Override

server/src/main/java/org/elasticsearch/rest/action/cat/RestSnapshotAction.java

@@ -9,11 +9,9 @@
 
 package org.elasticsearch.rest.action.cat;
 
-import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.snapshots.get.GetSnapshotsRequest;
 import org.elasticsearch.action.admin.cluster.snapshots.get.GetSnapshotsResponse;
 import org.elasticsearch.client.internal.node.NodeClient;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.Table;
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.core.TimeValue;
@@ -99,24 +97,6 @@ protected Table getTableWithHeader(RestRequest request) {
     private Table buildTable(RestRequest req, GetSnapshotsResponse getSnapshotsResponse) {
         Table table = getTableWithHeader(req);
 
-        if (getSnapshotsResponse.isFailed()) {
-            ElasticsearchException causes = null;
-
-            for (ElasticsearchException e : getSnapshotsResponse.getFailures().values()) {
-                if (causes == null) {
-                    causes = e;
-                } else {
-                    causes.addSuppressed(e);
-                }
-            }
-            throw new ElasticsearchException(
-                "Repositories ["
-                    + Strings.collectionToCommaDelimitedString(getSnapshotsResponse.getFailures().keySet())
-                    + "] failed to retrieve snapshots",
-                causes
-            );
-        }
-
         for (SnapshotInfo snapshotStatus : getSnapshotsResponse.getSnapshots()) {
             table.startRow();
 

server/src/test/java/org/elasticsearch/action/admin/cluster/snapshots/get/GetSnapshotsResponseTests.java

@@ -37,8 +37,6 @@
 import java.util.Map;
 import java.util.Set;
 
-import static org.hamcrest.CoreMatchers.containsString;
-
 public class GetSnapshotsResponseTests extends ESTestCase {
     // We can not subclass AbstractSerializingTestCase because it
     // can only be used for instances with equals and hashCode
@@ -60,12 +58,6 @@ private GetSnapshotsResponse copyInstance(GetSnapshotsResponse instance) throws
     private void assertEqualInstances(GetSnapshotsResponse expectedInstance, GetSnapshotsResponse newInstance) {
         assertEquals(expectedInstance.getSnapshots(), newInstance.getSnapshots());
         assertEquals(expectedInstance.next(), newInstance.next());
-        assertEquals(expectedInstance.getFailures().keySet(), newInstance.getFailures().keySet());
-        for (Map.Entry<String, ElasticsearchException> expectedEntry : expectedInstance.getFailures().entrySet()) {
-            ElasticsearchException expectedException = expectedEntry.getValue();
-            ElasticsearchException newException = newInstance.getFailures().get(expectedEntry.getKey());
-            assertThat(newException.getMessage(), containsString(expectedException.getMessage()));
-        }
     }
 
     private List<SnapshotInfo> createSnapshotInfos(String repoName) {