Enable remote segment upload backpressure by default

CHANGELOG.md

@@ -124,6 +124,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Tracing Framework] Add support for SpanKind. ([#10122](https://github.com/opensearch-project/OpenSearch/pull/10122))
 - Pass parent filter to inner query in nested query ([#10246](https://github.com/opensearch-project/OpenSearch/pull/10246))
 - Disable concurrent segment search when terminate_after is used ([#10200](https://github.com/opensearch-project/OpenSearch/pull/10200))
+- Enable remote segment upload backpressure by default ([#10356](https://github.com/opensearch-project/OpenSearch/pull/10356))
 
 ### Deprecated
 
@@ -141,4 +142,4 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Security
 
 [Unreleased 3.0]: https://github.com/opensearch-project/OpenSearch/compare/2.x...HEAD
-[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.11...2.x
+[Unreleased 2.x]: https://github.com/opensearch-project/OpenSearch/compare/2.11...2.x

server/src/main/java/org/opensearch/index/remote/RemoteStorePressureSettings.java

@@ -30,7 +30,7 @@ static class Defaults {
 
     public static final Setting<Boolean> REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED = Setting.boolSetting(
         "remote_store.segment.pressure.enabled",
-        false,
+        true,
         Setting.Property.Dynamic,
         Setting.Property.NodeScope
     );

server/src/test/java/org/opensearch/index/remote/RemoteStorePressureServiceTests.java

@@ -58,7 +58,7 @@ public void tearDown() throws Exception {
     public void testIsSegmentsUploadBackpressureEnabled() {
         remoteStoreStatsTrackerFactory = new RemoteStoreStatsTrackerFactory(clusterService, Settings.EMPTY);
         pressureService = new RemoteStorePressureService(clusterService, Settings.EMPTY, remoteStoreStatsTrackerFactory);
-        assertFalse(pressureService.isSegmentsUploadBackpressureEnabled());
+        assertTrue(pressureService.isSegmentsUploadBackpressureEnabled());
 
         Settings newSettings = Settings.builder()
             .put(RemoteStorePressureSettings.REMOTE_REFRESH_SEGMENT_PRESSURE_ENABLED.getKey(), "true")

server/src/test/java/org/opensearch/index/remote/RemoteStorePressureSettingsTests.java

@@ -48,7 +48,7 @@ public void testGetDefaultSettings() {
         );
 
         // Check remote refresh segment pressure enabled is false
-        assertFalse(pressureSettings.isRemoteRefreshSegmentPressureEnabled());
+        assertTrue(pressureSettings.isRemoteRefreshSegmentPressureEnabled());
 
         // Check bytes lag variance threshold default value
         assertEquals(10.0, pressureSettings.getBytesLagVarianceFactor(), 0.0d);