From 51810f27ad1cf284813706f18c7eafd11e0c13ac Mon Sep 17 00:00:00 2001
From: Florian Bernd <florian.bernd@elastic.co>
Date: Tue, 19 Aug 2025 10:14:01 +0200
Subject: [PATCH] Fix race condition in `GetOrCreateBoundConfiguration`

---
 src/Elastic.Transport/DistributedTransport.cs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/Elastic.Transport/DistributedTransport.cs b/src/Elastic.Transport/DistributedTransport.cs
index 018ca33..99373b4 100644
--- a/src/Elastic.Transport/DistributedTransport.cs
+++ b/src/Elastic.Transport/DistributedTransport.cs
@@ -305,13 +305,20 @@ BoundConfiguration GetOrCreateBoundConfiguration(RequestConfiguration rc)
 				return boundConfiguration;
 			}
 
+#if NET8_0_OR_GREATER
 			boundConfiguration = new BoundConfiguration(Configuration, rc);
 
-#if NET8_0_OR_GREATER
 			cache.TryAdd(rc, boundConfiguration);
 #else
 			lock (cache)
 			{
+				if (cache.TryGetValue(rc, out boundConfiguration))
+				{
+					return boundConfiguration;
+				}
+
+				boundConfiguration = new BoundConfiguration(Configuration, rc);
+
 				cache.Add(rc, boundConfiguration);
 			}
 #endif