Include size of snapshot in snapshot metadata #18543, bwc clean up (#30890)

docs/reference/modules/snapshots.asciidoc

@@ -597,12 +597,7 @@ The output looks similar to the following:
           "size_in_bytes": 4704
         },
         "start_time_in_millis": 1526280280355,
-        "time_in_millis": 358,
-
-        "number_of_files": 8,
-        "processed_files": 8,
-        "total_size_in_bytes": 4704,
-        "processed_size_in_bytes": 4704
+        "time_in_millis": 358
       }
     }
   ]
@@ -616,9 +611,6 @@ the `stats` object contains a `total` section for all the files that are referen
 for those files that actually needed to be copied over as part of the incremental snapshotting. In case of a snapshot that's still
 in progress, there's also a `processed` section that contains information about the files that are in the process of being copied.
 
-_Note_: Properties `number_of_files`, `processed_files`, `total_size_in_bytes` and `processed_size_in_bytes` are used for
-backward compatibility reasons with older 5.x and 6.x versions. These fields will be removed in Elasticsearch v7.0.0.
-
 Multiple ids are also supported:
 
 [source,sh]

rest-api-spec/src/main/resources/rest-api-spec/test/snapshot.status/10_basic.yml

@@ -11,9 +11,6 @@ setup:
 
 ---
 "Get snapshot status":
-  - skip:
-      version:     " - 6.99.99"
-      reason:      "backporting in progress: https://github.com/elastic/elasticsearch/pull/29602"
   - do:
       indices.create:
         index: test_index
@@ -39,38 +36,10 @@ setup:
   - gt: { snapshots.0.stats.incremental.file_count: 0 }
   - gt: { snapshots.0.stats.incremental.size_in_bytes: 0 }
   - gt: { snapshots.0.stats.total.file_count: 0 }
+  - gt: { snapshots.0.stats.total.size_in_bytes: 0 }
   - is_true: snapshots.0.stats.start_time_in_millis
   - is_true: snapshots.0.stats.time_in_millis
 
----
-"Get snapshot status with BWC fields":
-  - do:
-      indices.create:
-        index: test_index
-        body:
-          settings:
-            number_of_shards:   1
-            number_of_replicas: 0
-
-  - do:
-      snapshot.create:
-        repository: test_repo_status_1
-        snapshot: test_snapshot_bwc
-        wait_for_completion: true
-
-  - do:
-      snapshot.status:
-        repository: test_repo_status_1
-        snapshot: test_snapshot_bwc
-
-  - is_true: snapshots
-  - match: { snapshots.0.snapshot: test_snapshot_bwc }
-  - match: { snapshots.0.state: SUCCESS }
-  - gt: { snapshots.0.stats.number_of_files: 0 }
-  - gt: { snapshots.0.stats.processed_files: 0 }
-  - gt: { snapshots.0.stats.total_size_in_bytes: 0 }
-  - gt: { snapshots.0.stats.processed_size_in_bytes: 0 }
-
 ---
 "Get missing snapshot status throws an exception":
 

server/src/main/java/org/elasticsearch/action/admin/cluster/snapshots/status/SnapshotStats.java

@@ -132,7 +132,7 @@ public class SnapshotStats implements Streamable, ToXContentFragment {
         out.writeVLong(incrementalSize);
         out.writeVLong(processedSize);
 
-        if (out.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+        if (out.getVersion().onOrAfter(Version.V_6_4_0)) {
             out.writeVInt(totalFileCount);
             out.writeVLong(totalSize);
         }
@@ -149,7 +149,7 @@ public class SnapshotStats implements Streamable, ToXContentFragment {
         incrementalSize = in.readVLong();
         processedSize = in.readVLong();
 
-        if (in.getVersion().onOrAfter(Version.V_7_0_0_alpha1)) {
+        if (in.getVersion().onOrAfter(Version.V_6_4_0)) {
             totalFileCount = in.readVInt();
             totalSize = in.readVLong();
         } else {
@@ -172,15 +172,6 @@ public class SnapshotStats implements Streamable, ToXContentFragment {
         static final String START_TIME_IN_MILLIS = "start_time_in_millis";
         static final String TIME_IN_MILLIS = "time_in_millis";
         static final String TIME = "time";
-
-        // BWC
-        static final String NUMBER_OF_FILES = "number_of_files";
-        static final String PROCESSED_FILES = "processed_files";
-        static final String TOTAL_SIZE = "total_size";
-        static final String TOTAL_SIZE_IN_BYTES = "total_size_in_bytes";
-        static final String PROCESSED_SIZE_IN_BYTES = "processed_size_in_bytes";
-        static final String PROCESSED_SIZE = "processed_size";
-
     }
 
     @Override
@@ -211,13 +202,7 @@ public class SnapshotStats implements Streamable, ToXContentFragment {
        builder.field(Fields.START_TIME_IN_MILLIS, getStartTime())
             .humanReadableField(Fields.TIME_IN_MILLIS, Fields.TIME, new TimeValue(getTime()));
 
-        // BWC part
-        return builder.field(Fields.NUMBER_OF_FILES, getIncrementalFileCount())
-            .field(Fields.PROCESSED_FILES, getProcessedFileCount())
-            .humanReadableField(Fields.TOTAL_SIZE_IN_BYTES, Fields.TOTAL_SIZE, new ByteSizeValue(getIncrementalSize()))
-            .humanReadableField(Fields.PROCESSED_SIZE_IN_BYTES, Fields.PROCESSED_SIZE, new ByteSizeValue(getProcessedSize()))
-            // BWC part ends
-            .endObject();
+        return builder.endObject();
     }
 
     void add(SnapshotStats stats) {

server/src/test/java/org/elasticsearch/action/admin/cluster/snapshots/status/SnapshotStatusTests.java

@@ -100,11 +100,7 @@ public class SnapshotStatusTests extends ESTestCase {
             "      \"size_in_bytes\" : 0\n" +
             "    },\n" +
             "    \"start_time_in_millis\" : 0,\n" +
-            "    \"time_in_millis\" : 0,\n" +
-            "    \"number_of_files\" : 0,\n" +
-            "    \"processed_files\" : 0,\n" +
-            "    \"total_size_in_bytes\" : 0,\n" +
-            "    \"processed_size_in_bytes\" : 0\n" +
+            "    \"time_in_millis\" : 0\n" +
             "  },\n" +
             "  \"indices\" : {\n" +
             "    \"" + indexName + "\" : {\n" +
@@ -126,11 +122,7 @@ public class SnapshotStatusTests extends ESTestCase {
             "          \"size_in_bytes\" : 0\n" +
             "        },\n" +
             "        \"start_time_in_millis\" : 0,\n" +
-            "        \"time_in_millis\" : 0,\n" +
-            "        \"number_of_files\" : 0,\n" +
-            "        \"processed_files\" : 0,\n" +
-            "        \"total_size_in_bytes\" : 0,\n" +
-            "        \"processed_size_in_bytes\" : 0\n" +
+            "        \"time_in_millis\" : 0\n" +
             "      },\n" +
             "      \"shards\" : {\n" +
             "        \"" + shardId + "\" : {\n" +
@@ -145,11 +137,7 @@ public class SnapshotStatusTests extends ESTestCase {
             "              \"size_in_bytes\" : 0\n" +
             "            },\n" +
             "            \"start_time_in_millis\" : 0,\n" +
-            "            \"time_in_millis\" : 0,\n" +
-            "            \"number_of_files\" : 0,\n" +
-            "            \"processed_files\" : 0,\n" +
-            "            \"total_size_in_bytes\" : 0,\n" +
-            "            \"processed_size_in_bytes\" : 0\n" +
+            "            \"time_in_millis\" : 0\n" +
             "          }\n" +
             "        }\n" +
             "      }\n" +