Total data set size in stats (#70625) (#71057)

With shared cache searchable snapshots we have shards that have a size
in S3 that differs from the locally occupied disk space. This commit
introduces `store.total_data_set_size` to node and indices stats, allowing to
differ between the two.

Relates #69820

docs/reference/cluster/nodes-stats.asciidoc

@@ -256,6 +256,16 @@ Total size of all shards assigned to the node.
 (integer)
 Total size, in bytes, of all shards assigned to the node.
 
+`total_data_set_size`::
+(<<byte-units,byte value>>)
+Total data set size of all shards assigned to the node.
+This includes the size of shards not stored fully on the node (shared cache searchable snapshots).
+
+`total_data_set_size_in_bytes`::
+(integer)
+Total data set size, in bytes, of all shards assigned to the node.
+This includes the size of shards not stored fully on the node (shared cache searchable snapshots).
+
 `reserved`::
 (<<byte-units,byte value>>)
 A prediction of how much larger the shard stores on this node will eventually

docs/reference/cluster/stats.asciidoc

@@ -240,6 +240,16 @@ Total size of all shards assigned to selected nodes.
 (integer)
 Total size, in bytes, of all shards assigned to selected nodes.
 
+`total_data_set_size`::
+(<<byte-units, byte units>>)
+Total data set size of all shards assigned to selected nodes.
+This includes the size of shards not stored fully on the nodes (shared cache searchable snapshots).
+
+`total_data_set_size_in_bytes`::
+(integer)
+Total data set size, in bytes, of all shards assigned to selected nodes.
+This includes the size of shards not stored fully on the nodes (shared cache searchable snapshots).
+
 `reserved`::
 (<<byte-units,byte value>>)
 A prediction of how much larger the shard stores will eventually grow due to
@@ -1238,6 +1248,8 @@ The API returns the following response:
       "store": {
          "size": "16.2kb",
          "size_in_bytes": 16684,
+         "total_data_set_size": "16.2kb",
+         "total_data_set_size_in_bytes": 16684,
          "reserved": "0b",
          "reserved_in_bytes": 0
       },

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/nodes.stats/40_store_stats.yml

@@ -1,9 +1,35 @@
 ---
 "Store stats":
   - skip:
-      version: " - 7.99.99"
-      reason: "reserved_in_bytes field is not returned in prior versions"
       features: [arbitrary_key]
+      version: " - 7.12.99"
+      reason:  "total_data_set_size added in 7.13"
+
+  - do:
+      nodes.info:
+        node_id: _master
+  - set:
+      nodes._arbitrary_key_: master
+
+  - do:
+      nodes.stats:
+        metric: [ indices ]
+        index_metric: [ store ]
+
+  - is_false: nodes.$master.discovery
+  - is_true:  nodes.$master.indices.store
+  - gte: { nodes.$master.indices.store.size_in_bytes: 0 }
+  - gte: { nodes.$master.indices.store.reserved_in_bytes: -1 }
+  - set:
+      nodes.$master.indices.store.size_in_bytes: size_in_bytes
+  - match: { nodes.$master.indices.store.total_data_set_size_in_bytes: $size_in_bytes }
+
+---
+"Store stats bwc":
+  - skip:
+      features: [arbitrary_key]
+      version: " - 7.8.99"
+      reason: "reserved_in_bytes field is not returned in prior versions"
 
   - do:
       nodes.info:

server/src/main/java/org/elasticsearch/index/IndexService.java

@@ -92,6 +92,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.LongSupplier;
+import java.util.function.LongUnaryOperator;
 import java.util.function.Supplier;
 
 import static java.util.Collections.emptyMap;
@@ -373,7 +374,7 @@ private long getAvgShardSizeInBytes() throws IOException {
         long sum = 0;
         int count = 0;
         for (IndexShard indexShard : this) {
-            sum += indexShard.store().stats(0L).sizeInBytes();
+            sum += indexShard.store().stats(0L, LongUnaryOperator.identity()).sizeInBytes();
             count++;
         }
         if (count == 0) {

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -180,6 +180,7 @@
 import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.LongSupplier;
+import java.util.function.LongUnaryOperator;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
@@ -1089,15 +1090,16 @@ public GetStats getStats() {
     }
 
     public StoreStats storeStats() {
-        if (DiskThresholdDecider.SETTING_IGNORE_DISK_WATERMARKS.get(indexSettings.getSettings())) {
-            // if this shard has no disk footprint then its size is reported as 0
-            return new StoreStats(0, 0);
-        }
         try {
             final RecoveryState recoveryState = this.recoveryState;
-            final long bytesStillToRecover = recoveryState == null ? -1L : recoveryState.getIndex().bytesStillToRecover();
-            final long reservedBytes = bytesStillToRecover == -1 ? StoreStats.UNKNOWN_RESERVED_BYTES : bytesStillToRecover;
-            return store.stats(reservedBytes);
+            if (DiskThresholdDecider.SETTING_IGNORE_DISK_WATERMARKS.get(indexSettings.getSettings())) {
+                // if this shard has no disk footprint then its local size is reported as 0
+                return store.stats(0, size -> 0);
+            } else {
+                final long bytesStillToRecover = recoveryState == null ? -1L : recoveryState.getIndex().bytesStillToRecover();
+                final long reservedBytes = bytesStillToRecover == -1 ? StoreStats.UNKNOWN_RESERVED_BYTES : bytesStillToRecover;
+                return store.stats(reservedBytes, LongUnaryOperator.identity());
+            }
         } catch (IOException e) {
             failShard("Failing shard because of exception during storeStats", e);
             throw new ElasticsearchException("io exception while building 'store stats'", e);

server/src/main/java/org/elasticsearch/index/store/Store.java

@@ -91,6 +91,7 @@
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.function.Consumer;
+import java.util.function.LongUnaryOperator;
 import java.util.zip.CRC32;
 import java.util.zip.Checksum;
 
@@ -346,10 +347,12 @@ public CheckIndex.Status checkIndex(PrintStream out) throws IOException {
 
     /**
      * @param reservedBytes a prediction of how much larger the store is expected to grow, or {@link StoreStats#UNKNOWN_RESERVED_BYTES}.
+     * @param localSizeFunction to calculate the local size of the shard based on the shard size.
      */
-    public StoreStats stats(long reservedBytes) throws IOException {
+    public StoreStats stats(long reservedBytes, LongUnaryOperator localSizeFunction) throws IOException {
         ensureOpen();
-        return new StoreStats(directory.estimateSize(), reservedBytes);
+        long sizeInBytes = directory.estimateSize();
+        return new StoreStats(localSizeFunction.applyAsLong(sizeInBytes), sizeInBytes, reservedBytes);
     }
 
     /**

server/src/main/java/org/elasticsearch/index/store/StoreStats.java

@@ -27,8 +27,10 @@ public class StoreStats implements Writeable, ToXContentFragment {
     public static final long UNKNOWN_RESERVED_BYTES = -1L;
 
     public static final Version RESERVED_BYTES_VERSION = Version.V_7_9_0;
+    public static final Version TOTAL_DATA_SET_SIZE_SIZE_VERSION = Version.V_7_13_0;
 
     private long sizeInBytes;
+    private long totalDataSetSizeInBytes;
     private long reservedSize;
 
     public StoreStats() {
@@ -40,6 +42,11 @@ public StoreStats(StreamInput in) throws IOException {
         if (in.getVersion().before(Version.V_6_0_0_alpha1)) {
             in.readVLong(); // throttleTimeInNanos
         }
+        if (in.getVersion().onOrAfter(TOTAL_DATA_SET_SIZE_SIZE_VERSION)) {
+            totalDataSetSizeInBytes = in.readVLong();
+        } else {
+            totalDataSetSizeInBytes = sizeInBytes;
+        }
         if (in.getVersion().onOrAfter(RESERVED_BYTES_VERSION)) {
             reservedSize = in.readZLong();
         } else {
@@ -49,19 +56,22 @@ public StoreStats(StreamInput in) throws IOException {
 
     /**
      * @param sizeInBytes the size of the store in bytes
+     * @param totalDataSetSizeInBytes the size of the total data set in bytes, can differ from sizeInBytes for shards using shared cache
+     *                                storage
      * @param reservedSize a prediction of how much larger the store is expected to grow, or {@link StoreStats#UNKNOWN_RESERVED_BYTES}.
      */
-    public StoreStats(long sizeInBytes, long reservedSize) {
+    public StoreStats(long sizeInBytes, long totalDataSetSizeInBytes, long reservedSize) {
         assert reservedSize == UNKNOWN_RESERVED_BYTES || reservedSize >= 0 : reservedSize;
         this.sizeInBytes = sizeInBytes;
+        this.totalDataSetSizeInBytes = totalDataSetSizeInBytes;
         this.reservedSize = reservedSize;
     }
-
     public void add(StoreStats stats) {
         if (stats == null) {
             return;
         }
         sizeInBytes += stats.sizeInBytes;
+        totalDataSetSizeInBytes += stats.totalDataSetSizeInBytes;
         reservedSize = ignoreIfUnknown(reservedSize) + ignoreIfUnknown(stats.reservedSize);
     }
 
@@ -85,6 +95,14 @@ public ByteSizeValue getSize() {
         return size();
     }
 
+    public ByteSizeValue totalDataSetSize() {
+        return new ByteSizeValue(totalDataSetSizeInBytes);
+    }
+
+    public ByteSizeValue getTotalDataSetSize() {
+        return totalDataSetSize();
+    }
+
     /**
      * A prediction of how much larger this store will eventually grow. For instance, if we are currently doing a peer recovery or restoring
      * a snapshot into this store then we can account for the rest of the recovery using this field. A value of {@code -1B} indicates that
@@ -100,6 +118,9 @@ public void writeTo(StreamOutput out) throws IOException {
         if (out.getVersion().before(Version.V_6_0_0_alpha1)) {
             out.writeVLong(0L); // throttleTimeInNanos
         }
+        if (out.getVersion().onOrAfter(TOTAL_DATA_SET_SIZE_SIZE_VERSION)) {
+            out.writeVLong(totalDataSetSizeInBytes);
+        }
         if (out.getVersion().onOrAfter(RESERVED_BYTES_VERSION)) {
             out.writeZLong(reservedSize);
         }
@@ -109,6 +130,7 @@ public void writeTo(StreamOutput out) throws IOException {
     public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
         builder.startObject(Fields.STORE);
         builder.humanReadableField(Fields.SIZE_IN_BYTES, Fields.SIZE, size());
+        builder.humanReadableField(Fields.TOTAL_DATA_SET_SIZE_IN_BYTES, Fields.TOTAL_DATA_SET_SIZE, totalDataSetSize());
         builder.humanReadableField(Fields.RESERVED_IN_BYTES, Fields.RESERVED, getReservedSize());
         builder.endObject();
         return builder;
@@ -118,6 +140,8 @@ static final class Fields {
         static final String STORE = "store";
         static final String SIZE = "size";
         static final String SIZE_IN_BYTES = "size_in_bytes";
+        static final String TOTAL_DATA_SET_SIZE = "total_data_set_size";
+        static final String TOTAL_DATA_SET_SIZE_IN_BYTES = "total_data_set_size_in_bytes";
         static final String RESERVED = "reserved";
         static final String RESERVED_IN_BYTES = "reserved_in_bytes";
     }

server/src/test/java/org/elasticsearch/action/admin/cluster/stats/VersionStatsTests.java

@@ -99,7 +99,7 @@ public void testCreation() {
         Path path = createTempDir().resolve("indices").resolve(shardRouting.shardId().getIndex().getUUID())
             .resolve(String.valueOf(shardRouting.shardId().id()));
         IndexShard indexShard = mock(IndexShard.class);
-        StoreStats storeStats = new StoreStats(100, 200);
+        StoreStats storeStats = new StoreStats(100, 150, 200);
         when(indexShard.storeStats()).thenReturn(storeStats);
         ShardStats shardStats = new ShardStats(shardRouting, new ShardPath(false, path, path, shardRouting.shardId()),
             new CommonStats(null, indexShard, new CommonStatsFlags(CommonStatsFlags.Flag.Store)),

server/src/test/java/org/elasticsearch/action/admin/indices/shrink/TransportResizeActionTests.java

@@ -70,7 +70,8 @@ public void testErrorCondition() {
         assertTrue(
             expectThrows(IllegalStateException.class, () ->
                 TransportResizeAction.prepareCreateIndexRequest(new ResizeRequest("target", "source"), state,
-                    new StoreStats(between(1, 100), between(1, 100)), (i) -> new DocsStats(Integer.MAX_VALUE, between(1, 1000),
+                    new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
+                    (i) -> new DocsStats(Integer.MAX_VALUE, between(1, 1000),
                         between(1, 100)), "target")
         ).getMessage().startsWith("Can't merge index with more than [2147483519] docs - too many documents in shards "));
 
@@ -82,7 +83,7 @@ public void testErrorCondition() {
                     TransportResizeAction.prepareCreateIndexRequest(req,
                             createClusterState("source", 8, 1,
                                     Settings.builder().put("index.blocks.write", true).build()).metadata().index("source"),
-                        new StoreStats(between(1, 100), between(1, 100)),
+                        new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
                         (i) -> i == 2 || i == 3 ? new DocsStats(Integer.MAX_VALUE / 2, between(1, 1000), between(1, 10000)) : null
                         , "target");
                 }
@@ -96,7 +97,7 @@ public void testErrorCondition() {
                     createClusterState("source", 8, 1,
                             Settings.builder().put("index.blocks.write", true).put("index.soft_deletes.enabled", true).build())
                             .metadata().index("source"),
-                new StoreStats(between(1, 100), between(1, 100)),
+                new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
                 (i) -> new DocsStats(between(10, 1000), between(1, 10), between(1, 10000)), "target");
         });
         assertThat(softDeletesError.getMessage(), equalTo("Can't disable [index.soft_deletes.enabled] setting on resize"));
@@ -117,7 +118,7 @@ public void testErrorCondition() {
         clusterState = ClusterState.builder(clusterState).routingTable(routingTable).build();
 
         TransportResizeAction.prepareCreateIndexRequest(new ResizeRequest("target", "source"), clusterState.metadata().index("source"),
-            new StoreStats(between(1, 100), between(1, 100)),
+            new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
             (i) -> new DocsStats(between(1, 1000), between(1, 1000), between(0, 10000)), "target");
     }
 
@@ -141,15 +142,17 @@ public void testPassNumRoutingShards() {
         resizeRequest.getTargetIndexRequest()
             .settings(Settings.builder().put("index.number_of_shards", 2).build());
         IndexMetadata indexMetadata = clusterState.metadata().index("source");
-        TransportResizeAction.prepareCreateIndexRequest(resizeRequest, indexMetadata, new StoreStats(between(1, 100), between(1, 100)),
+        TransportResizeAction.prepareCreateIndexRequest(resizeRequest, indexMetadata,
+            new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
             null, "target");
 
         resizeRequest.getTargetIndexRequest()
             .settings(Settings.builder()
                 .put("index.number_of_routing_shards", randomIntBetween(2, 10))
                 .put("index.number_of_shards", 2)
                 .build());
-        TransportResizeAction.prepareCreateIndexRequest(resizeRequest, indexMetadata, new StoreStats(between(1, 100), between(1, 100)),
+        TransportResizeAction.prepareCreateIndexRequest(resizeRequest, indexMetadata,
+            new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
             null, "target");
     }
 
@@ -174,7 +177,7 @@ public void testPassNumRoutingShardsAndFail() {
         resizeRequest.getTargetIndexRequest()
             .settings(Settings.builder().put("index.number_of_shards", numShards * 2).build());
         TransportResizeAction.prepareCreateIndexRequest(resizeRequest, clusterState.metadata().index("source"),
-            new StoreStats(between(1, 100), between(1, 100)), null, "target");
+            new StoreStats(between(1, 100), between(0, 100), between(1, 100)), null, "target");
 
         resizeRequest.getTargetIndexRequest()
             .settings(Settings.builder()
@@ -183,7 +186,7 @@ public void testPassNumRoutingShardsAndFail() {
         ClusterState finalState = clusterState;
         IllegalArgumentException iae = expectThrows(IllegalArgumentException.class,
             () -> TransportResizeAction.prepareCreateIndexRequest(resizeRequest, finalState.metadata().index("source"),
-                new StoreStats(between(1, 100), between(1, 100)), null, "target"));
+                new StoreStats(between(1, 100), between(0, 100), between(1, 100)), null, "target"));
         assertEquals("cannot provide index.number_of_routing_shards on resize", iae.getMessage());
     }
 
@@ -211,7 +214,8 @@ public void testShrinkIndexSettings() {
         final ActiveShardCount activeShardCount = randomBoolean() ? ActiveShardCount.ALL : ActiveShardCount.ONE;
         target.setWaitForActiveShards(activeShardCount);
         CreateIndexClusterStateUpdateRequest request = TransportResizeAction.prepareCreateIndexRequest(
-            target, clusterState.metadata().index(indexName), new StoreStats(between(1, 100), between(1, 100)), (i) -> stats, "target");
+            target, clusterState.metadata().index(indexName),
+            new StoreStats(between(1, 100), between(0, 100), between(1, 100)), (i) -> stats, "target");
         assertNotNull(request.recoverFrom());
         assertEquals(indexName, request.recoverFrom().getName());
         assertEquals("1", request.settings().get("index.number_of_shards"));
@@ -242,7 +246,8 @@ public void testShrinkWithMaxPrimaryShardSize() {
             .settings(Settings.builder().put("index.number_of_shards", 2).build());
         assertTrue(
             expectThrows(IllegalArgumentException.class, () ->
-                TransportResizeAction.prepareCreateIndexRequest(resizeRequest, state, new StoreStats(between(1, 100), between(1, 100)),
+                TransportResizeAction.prepareCreateIndexRequest(resizeRequest, state,
+                    new StoreStats(between(1, 100), between(0, 100), between(1, 100)),
                     (i) -> new DocsStats(Integer.MAX_VALUE, between(1, 1000), between(1, 100)), "target")
             ).getMessage().startsWith("Cannot set both index.number_of_shards and max_primary_shard_size for the target index"));
 
@@ -268,7 +273,7 @@ public void testShrinkWithMaxPrimaryShardSize() {
         // each shard's storage will not be greater than the `max_primary_shard_size`
         ResizeRequest target1 = new ResizeRequest("target", "source");
         target1.setMaxPrimaryShardSize(new ByteSizeValue(2));
-        StoreStats storeStats = new StoreStats(10, between(1, 100));
+        StoreStats storeStats = new StoreStats(10, between(0, 100), between(1, 100));
         final int targetIndexShardsNum1 = 5;
         final ActiveShardCount activeShardCount1 = ActiveShardCount.from(targetIndexShardsNum1);
         target1.setWaitForActiveShards(targetIndexShardsNum1);
@@ -285,7 +290,7 @@ public void testShrinkWithMaxPrimaryShardSize() {
         // the shards number of the target index will be equal to the source index's shards number
         ResizeRequest target2 = new ResizeRequest("target2", "source");
         target2.setMaxPrimaryShardSize(new ByteSizeValue(1));
-        StoreStats storeStats2 = new StoreStats(100, between(1, 100));
+        StoreStats storeStats2 = new StoreStats(100, between(0, 100), between(1, 100));
         final int targetIndexShardsNum2 = 10;
         final ActiveShardCount activeShardCount2 = ActiveShardCount.from(targetIndexShardsNum2);
         target2.setWaitForActiveShards(activeShardCount2);