From 4230d72c2205dc9db43497e5ccfab6a0e7d3464c Mon Sep 17 00:00:00 2001
From: Nhat Nguyen <nhat.nguyen@elastic.co>
Date: Wed, 4 Dec 2024 08:42:34 -0800
Subject: [PATCH] Acquire stats searcher for data stream stats (#117953)
 (#118006)

Here, we only need to extract the minimum and maximum values of the
timestamp field; therefore, using a stats searcher should suffice. This
is important for frozen indices.
---
 docs/changelog/117953.yaml                                   | 5 +++++
 .../datastreams/action/DataStreamsStatsTransportAction.java  | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 docs/changelog/117953.yaml

diff --git a/docs/changelog/117953.yaml b/docs/changelog/117953.yaml
new file mode 100644
index 0000000000000..62f0218b1cdc7
--- /dev/null
+++ b/docs/changelog/117953.yaml
@@ -0,0 +1,5 @@
+pr: 117953
+summary: Acquire stats searcher for data stream stats
+area: Data streams
+type: bug
+issues: []
diff --git a/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/DataStreamsStatsTransportAction.java b/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/DataStreamsStatsTransportAction.java
index 1b0b0aa6abebe..1d3b1b676282a 100644
--- a/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/DataStreamsStatsTransportAction.java
+++ b/modules/data-streams/src/main/java/org/elasticsearch/datastreams/action/DataStreamsStatsTransportAction.java
@@ -31,6 +31,7 @@
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.engine.Engine;
+import org.elasticsearch.index.engine.ReadOnlyEngine;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.store.StoreStats;
 import org.elasticsearch.indices.IndicesService;
@@ -130,7 +131,7 @@ protected void shardOperation(
             DataStream dataStream = indexAbstraction.getParentDataStream();
             assert dataStream != null;
             long maxTimestamp = 0L;
-            try (Engine.Searcher searcher = indexShard.acquireSearcher("data_stream_stats")) {
+            try (Engine.Searcher searcher = indexShard.acquireSearcher(ReadOnlyEngine.FIELD_RANGE_SEARCH_SOURCE)) {
                 IndexReader indexReader = searcher.getIndexReader();
                 byte[] maxPackedValue = PointValues.getMaxPackedValue(indexReader, DataStream.TIMESTAMP_FIELD_NAME);
                 if (maxPackedValue != null) {