From d645e2088c3464320cb3b2d031a4a6ea07c58632 Mon Sep 17 00:00:00 2001
From: "github-actions[bot]" <github-actions[bot]@users.noreply.github.com>
Date: Tue, 16 Apr 2024 13:18:10 +0000
Subject: [PATCH] Add warn logs for remote backpressure rejection (#13218)

Signed-off-by: Gaurav Bafna <gbbafna@amazon.com>
(cherry picked from commit 8bd0ad94cbffac82c8fd4fb98ed5715830d78064)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
---
 .../opensearch/index/remote/RemoteStorePressureService.java   | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
index 33cd40f802d43..52f83096dc08d 100644
--- a/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
+++ b/server/src/main/java/org/opensearch/index/remote/RemoteStorePressureService.java
@@ -78,7 +78,9 @@ public void validateSegmentsUploadLag(ShardId shardId) {
         for (LagValidator lagValidator : lagValidators) {
             if (lagValidator.validate(remoteSegmentTransferTracker, shardId) == false) {
                 remoteSegmentTransferTracker.incrementRejectionCount(lagValidator.name());
-                throw new OpenSearchRejectedExecutionException(lagValidator.rejectionMessage(remoteSegmentTransferTracker, shardId));
+                String rejectionMessage = lagValidator.rejectionMessage(remoteSegmentTransferTracker, shardId);
+                logger.warn("Rejecting write requests for shard due to remote backpressure:  {}", rejectionMessage);
+                throw new OpenSearchRejectedExecutionException(rejectionMessage);
             }
         }
     }