Refactor ShardStats, WarmerStats and IndexingPressureStats with Builder pattern (#19966)

Author: pado0

CHANGELOG.md

@@ -68,6 +68,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Refactor the HttpStats, ScriptStats, AdaptiveSelectionStats and OsStats class to use the Builder pattern instead of constructors ([#20014](https://github.com/opensearch-project/OpenSearch/pull/20014))
 - Bump opensearch-protobufs dependency to 0.24.0 and update transport-grpc module compatibility ([#20059](https://github.com/opensearch-project/OpenSearch/pull/20059))
 
+- Refactor the ShardStats, WarmerStats and IndexingPressureStats class to use the Builder pattern instead of constructors ([#19966](https://github.com/opensearch-project/OpenSearch/pull/19966))
 
 ### Fixed
 - Fix Allocation and Rebalance Constraints of WeightFunction are incorrectly reset ([#19012](https://github.com/opensearch-project/OpenSearch/pull/19012))
@@ -142,6 +143,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Deprecated existing constructors in IndexPressutreStats, DeviceStats and TransportStats in favor of the new Builder ([#19991](https://github.com/opensearch-project/OpenSearch/pull/19991))
 - Deprecated existing constructors in Cache.CacheStats in favor of the new Builder ([#20015](https://github.com/opensearch-project/OpenSearch/pull/20015))
 - Deprecated existing constructors in HttpStats, ScriptStats, AdaptiveSelectionStats and OsStats in favor of the new Builder ([#20014](https://github.com/opensearch-project/OpenSearch/pull/20014))
+- Deprecated existing constructors in ShardStats, WarmerStats and IndexingPressureStats in favor of the new Builder ([#19966](https://github.com/opensearch-project/OpenSearch/pull/19966))
 
 ### Removed
 

server/src/main/java/org/opensearch/action/admin/cluster/stats/TransportClusterStatsAction.java

@@ -225,15 +225,14 @@ protected ClusterStatsNodeResponse nodeOperation(ClusterStatsNodeRequest nodeReq
                             pollingIngestStats = null;
                         }
                         shardsStats.add(
-                            new ShardStats(
-                                indexShard.routingEntry(),
-                                indexShard.shardPath(),
-                                new CommonStats(indicesService.getIndicesQueryCache(), indexShard, commonStatsFlags),
-                                commitStats,
-                                seqNoStats,
-                                retentionLeaseStats,
-                                pollingIngestStats
-                            )
+                            new ShardStats.Builder().shardRouting(indexShard.routingEntry())
+                                .shardPath(indexShard.shardPath())
+                                .commonStats(new CommonStats(indicesService.getIndicesQueryCache(), indexShard, commonStatsFlags))
+                                .commitStats(commitStats)
+                                .seqNoStats(seqNoStats)
+                                .retentionLeaseStats(retentionLeaseStats)
+                                .pollingIngestStats(pollingIngestStats)
+                                .build()
                         );
                     }
                 }
@@ -257,6 +256,7 @@ protected ClusterStatsNodeResponse nodeOperation(ClusterStatsNodeRequest nodeReq
 
     /**
      * A metric is required when: all cluster stats are required (OR) if the metric is requested
+     *
      * @param metric
      * @param clusterStatsRequest
      * @return

server/src/main/java/org/opensearch/action/admin/indices/stats/ShardStats.java

@@ -83,6 +83,23 @@ public RetentionLeaseStats getRetentionLeaseStats() {
     private String statePath;
     private boolean isCustomDataPath;
 
+    /**
+     * Private constructor that takes a builder.
+     * This is the sole entry point for creating a new ShardStats object.
+     * @param builder The builder instance containing all the values.
+     */
+    private ShardStats(Builder builder) {
+        this.shardRouting = builder.shardRouting;
+        this.dataPath = builder.shardPath.getRootDataPath().toString();
+        this.statePath = builder.shardPath.getRootStatePath().toString();
+        this.isCustomDataPath = builder.shardPath.isCustomDataPath();
+        this.commitStats = builder.commitStats;
+        this.commonStats = builder.commonStats;
+        this.seqNoStats = builder.seqNoStats;
+        this.retentionLeaseStats = builder.retentionLeaseStats;
+        this.pollingIngestStats = builder.pollingIngestStats;
+    }
+
     public ShardStats(StreamInput in) throws IOException {
         shardRouting = new ShardRouting(in);
         commonStats = new CommonStats(in);
@@ -97,6 +114,11 @@ public ShardStats(StreamInput in) throws IOException {
         }
     }
 
+    /**
+     * This constructor will be deprecated starting in version 3.4.0.
+     * Use {@link Builder} instead.
+     */
+    @Deprecated
     public ShardStats(
         final ShardRouting routing,
         final ShardPath shardPath,
@@ -155,6 +177,65 @@ public boolean isCustomDataPath() {
         return isCustomDataPath;
     }
 
+    /**
+     * Builder for the {@link ShardStats} class.
+     * Provides a fluent API for constructing a ShardStats object.
+     */
+    public static class Builder {
+        private ShardRouting shardRouting = null;
+        private ShardPath shardPath = null;
+        private CommonStats commonStats = null;
+        private CommitStats commitStats = null;
+        private SeqNoStats seqNoStats = null;
+        private RetentionLeaseStats retentionLeaseStats = null;
+        private PollingIngestStats pollingIngestStats = null;
+
+        public Builder() {}
+
+        public Builder shardRouting(ShardRouting shardRouting) {
+            this.shardRouting = shardRouting;
+            return this;
+        }
+
+        public Builder shardPath(ShardPath shardPath) {
+            this.shardPath = shardPath;
+            return this;
+        }
+
+        public Builder commonStats(CommonStats commonStats) {
+            this.commonStats = commonStats;
+            return this;
+        }
+
+        public Builder commitStats(CommitStats commitStats) {
+            this.commitStats = commitStats;
+            return this;
+        }
+
+        public Builder seqNoStats(SeqNoStats seqNoStats) {
+            this.seqNoStats = seqNoStats;
+            return this;
+        }
+
+        public Builder retentionLeaseStats(RetentionLeaseStats retentionLeaseStats) {
+            this.retentionLeaseStats = retentionLeaseStats;
+            return this;
+        }
+
+        public Builder pollingIngestStats(PollingIngestStats pollingIngestStats) {
+            this.pollingIngestStats = pollingIngestStats;
+            return this;
+        }
+
+        /**
+         * Creates a {@link ShardStats} object from the builder's current state.
+         * @return A new ShardStats instance.
+         */
+        public ShardStats build() {
+            return new ShardStats(this);
+        }
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         shardRouting.writeTo(out);

server/src/main/java/org/opensearch/action/admin/indices/stats/TransportIndicesStatsAction.java

@@ -155,14 +155,14 @@ protected ShardStats shardOperation(IndicesStatsRequest request, ShardRouting sh
             retentionLeaseStats = null;
             pollingIngestStats = null;
         }
-        return new ShardStats(
-            indexShard.routingEntry(),
-            indexShard.shardPath(),
-            commonStats,
-            commitStats,
-            seqNoStats,
-            retentionLeaseStats,
-            pollingIngestStats
-        );
+        return new ShardStats.Builder().shardRouting(indexShard.routingEntry())
+            .shardPath(indexShard.shardPath())
+            .commonStats(commonStats)
+            .commitStats(commitStats)
+            .seqNoStats(seqNoStats)
+            .retentionLeaseStats(retentionLeaseStats)
+            .pollingIngestStats(pollingIngestStats)
+            .build();
+
     }
 }

server/src/main/java/org/opensearch/index/IndexingPressure.java

@@ -218,19 +218,18 @@ public long getCurrentReplicaBytes() {
     }
 
     public IndexingPressureStats stats() {
-        return new IndexingPressureStats(
-            totalCombinedCoordinatingAndPrimaryBytes.get(),
-            totalCoordinatingBytes.get(),
-            totalPrimaryBytes.get(),
-            totalReplicaBytes.get(),
-            currentCombinedCoordinatingAndPrimaryBytes.get(),
-            currentCoordinatingBytes.get(),
-            currentPrimaryBytes.get(),
-            currentReplicaBytes.get(),
-            coordinatingRejections.get(),
-            primaryRejections.get(),
-            replicaRejections.get(),
-            primaryAndCoordinatingLimits
-        );
+        return new IndexingPressureStats.Builder().totalCombinedCoordinatingAndPrimaryBytes(totalCombinedCoordinatingAndPrimaryBytes.get())
+            .totalCoordinatingBytes(totalCoordinatingBytes.get())
+            .totalPrimaryBytes(totalPrimaryBytes.get())
+            .totalReplicaBytes(totalReplicaBytes.get())
+            .currentCombinedCoordinatingAndPrimaryBytes(currentCombinedCoordinatingAndPrimaryBytes.get())
+            .currentCoordinatingBytes(currentCoordinatingBytes.get())
+            .currentPrimaryBytes(currentPrimaryBytes.get())
+            .currentReplicaBytes(currentReplicaBytes.get())
+            .coordinatingRejections(coordinatingRejections.get())
+            .primaryRejections(primaryRejections.get())
+            .replicaRejections(replicaRejections.get())
+            .memoryLimit(primaryAndCoordinatingLimits)
+            .build();
     }
 }

server/src/main/java/org/opensearch/index/stats/IndexingPressureStats.java

@@ -64,6 +64,26 @@ public class IndexingPressureStats implements Writeable, ToXContentFragment {
     private final long replicaRejections;
     private final long memoryLimit;
 
+    /**
+     * Private constructor that takes a builder.
+     * This is the sole entry point for creating a new IndexingPressureStats object.
+     * @param builder The builder instance containing all the values.
+     */
+    private IndexingPressureStats(Builder builder) {
+        this.totalCombinedCoordinatingAndPrimaryBytes = builder.totalCombinedCoordinatingAndPrimaryBytes;
+        this.totalCoordinatingBytes = builder.totalCoordinatingBytes;
+        this.totalPrimaryBytes = builder.totalPrimaryBytes;
+        this.totalReplicaBytes = builder.totalReplicaBytes;
+        this.currentCombinedCoordinatingAndPrimaryBytes = builder.currentCombinedCoordinatingAndPrimaryBytes;
+        this.currentCoordinatingBytes = builder.currentCoordinatingBytes;
+        this.currentPrimaryBytes = builder.currentPrimaryBytes;
+        this.currentReplicaBytes = builder.currentReplicaBytes;
+        this.coordinatingRejections = builder.coordinatingRejections;
+        this.primaryRejections = builder.primaryRejections;
+        this.replicaRejections = builder.replicaRejections;
+        this.memoryLimit = builder.memoryLimit;
+    }
+
     public IndexingPressureStats(StreamInput in) throws IOException {
         totalCombinedCoordinatingAndPrimaryBytes = in.readVLong();
         totalCoordinatingBytes = in.readVLong();
@@ -81,6 +101,11 @@ public IndexingPressureStats(StreamInput in) throws IOException {
         memoryLimit = in.readVLong();
     }
 
+    /**
+     * This constructor will be deprecated starting in version 3.4.0.
+     * Use {@link Builder} instead.
+     */
+    @Deprecated
     public IndexingPressureStats(
         long totalCombinedCoordinatingAndPrimaryBytes,
         long totalCoordinatingBytes,
@@ -109,6 +134,95 @@ public IndexingPressureStats(
         this.memoryLimit = memoryLimit;
     }
 
+    /**
+     * Builder for the {@link IndexingPressureStats} class.
+     * Provides a fluent API for constructing a IndexingPressureStats object.
+     */
+    public static class Builder {
+        private long totalCombinedCoordinatingAndPrimaryBytes = 0;
+        private long totalCoordinatingBytes = 0;
+        private long totalPrimaryBytes = 0;
+        private long totalReplicaBytes = 0;
+        private long currentCombinedCoordinatingAndPrimaryBytes = 0;
+        private long currentCoordinatingBytes = 0;
+        private long currentPrimaryBytes = 0;
+        private long currentReplicaBytes = 0;
+        private long coordinatingRejections = 0;
+        private long primaryRejections = 0;
+        private long replicaRejections = 0;
+        private long memoryLimit = 0;
+
+        public Builder() {}
+
+        public Builder totalCombinedCoordinatingAndPrimaryBytes(long bytes) {
+            this.totalCombinedCoordinatingAndPrimaryBytes = bytes;
+            return this;
+        }
+
+        public Builder totalCoordinatingBytes(long bytes) {
+            this.totalCoordinatingBytes = bytes;
+            return this;
+        }
+
+        public Builder totalPrimaryBytes(long bytes) {
+            this.totalPrimaryBytes = bytes;
+            return this;
+        }
+
+        public Builder totalReplicaBytes(long bytes) {
+            this.totalReplicaBytes = bytes;
+            return this;
+        }
+
+        public Builder currentCombinedCoordinatingAndPrimaryBytes(long bytes) {
+            this.currentCombinedCoordinatingAndPrimaryBytes = bytes;
+            return this;
+        }
+
+        public Builder currentCoordinatingBytes(long bytes) {
+            this.currentCoordinatingBytes = bytes;
+            return this;
+        }
+
+        public Builder currentPrimaryBytes(long bytes) {
+            this.currentPrimaryBytes = bytes;
+            return this;
+        }
+
+        public Builder currentReplicaBytes(long bytes) {
+            this.currentReplicaBytes = bytes;
+            return this;
+        }
+
+        public Builder coordinatingRejections(long rejections) {
+            this.coordinatingRejections = rejections;
+            return this;
+        }
+
+        public Builder primaryRejections(long rejections) {
+            this.primaryRejections = rejections;
+            return this;
+        }
+
+        public Builder replicaRejections(long rejections) {
+            this.replicaRejections = rejections;
+            return this;
+        }
+
+        public Builder memoryLimit(long limit) {
+            this.memoryLimit = limit;
+            return this;
+        }
+
+        /**
+         * Creates a {@link IndexingPressureStats} object from the builder's current state.
+         * @return A new IndexingPressureStats instance.
+         */
+        public IndexingPressureStats build() {
+            return new IndexingPressureStats(this);
+        }
+    }
+
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         out.writeVLong(totalCombinedCoordinatingAndPrimaryBytes);

server/src/main/java/org/opensearch/index/warmer/ShardIndexWarmerService.java

@@ -71,6 +71,9 @@ public void onPostWarm(long tookInNanos) {
     }
 
     public WarmerStats stats() {
-        return new WarmerStats(current.count(), warmerMetric.count(), TimeUnit.NANOSECONDS.toMillis(warmerMetric.sum()));
+        return new WarmerStats.Builder().current(current.count())
+            .total(warmerMetric.count())
+            .totalTimeInMillis(TimeUnit.NANOSECONDS.toMillis(warmerMetric.sum()))
+            .build();
     }
 }