From 7867238bbc034b8096619b50e4c6c32538285362 Mon Sep 17 00:00:00 2001
From: David Turner <david.turner@elastic.co>
Date: Tue, 24 Jun 2025 18:30:11 +0100
Subject: [PATCH] Reverse disordered-version warning message (#129904)

The comment in `TransportHandshaker` indicates (correctly) that we emit
a warning when talking to a chronologically-newer-yet-numerically-older
version, but the wording of the warning message is inverted and says
that the remote is chronologically-older-yet-numerically-newer. This
commit straightens out the message to match the situation it is
describing.

Relates #123397
---
 docs/changelog/129904.yaml                           |  5 +++++
 .../elasticsearch/transport/TransportHandshaker.java |  4 ++--
 .../transport/TransportHandshakerTests.java          | 12 ++++++------
 3 files changed, 13 insertions(+), 8 deletions(-)
 create mode 100644 docs/changelog/129904.yaml

diff --git a/docs/changelog/129904.yaml b/docs/changelog/129904.yaml
new file mode 100644
index 0000000000000..f8945cac1d3c3
--- /dev/null
+++ b/docs/changelog/129904.yaml
@@ -0,0 +1,5 @@
+pr: 129904
+summary: Reverse disordered-version warning message
+area: Infra/Core
+type: bug
+issues: []
diff --git a/server/src/main/java/org/elasticsearch/transport/TransportHandshaker.java b/server/src/main/java/org/elasticsearch/transport/TransportHandshaker.java
index 17393a174aaac..4932390144c17 100644
--- a/server/src/main/java/org/elasticsearch/transport/TransportHandshaker.java
+++ b/server/src/main/java/org/elasticsearch/transport/TransportHandshaker.java
@@ -241,8 +241,8 @@ private static TransportVersion ensureCompatibleVersion(
                     logger.warn(
                         """
                             Negotiating transport handshake with remote node with version [{}/{}] received on [{}] which appears to be \
-                            from a chronologically-older release with a numerically-newer version compared to this node's version [{}/{}]. \
-                            Upgrading to a chronologically-older release may not work reliably and is not recommended. \
+                            from a chronologically-newer release with a numerically-older version compared to this node's version [{}/{}]. \
+                            Upgrading to this version from a chronologically-newer release may not work reliably and is not recommended. \
                             Falling back to transport protocol version [{}].""",
                         releaseVersion,
                         remoteTransportVersion,
diff --git a/server/src/test/java/org/elasticsearch/transport/TransportHandshakerTests.java b/server/src/test/java/org/elasticsearch/transport/TransportHandshakerTests.java
index c7270d077c2d9..8f5b8379a4b9b 100644
--- a/server/src/test/java/org/elasticsearch/transport/TransportHandshakerTests.java
+++ b/server/src/test/java/org/elasticsearch/transport/TransportHandshakerTests.java
@@ -134,9 +134,9 @@ public void testIncompatibleHandshakeRequest() throws Exception {
                     Strings.format(
                         """
                             Negotiating transport handshake with remote node with version [%s/%s] received on [*] which appears to be from \
-                            a chronologically-older release with a numerically-newer version compared to this node's version [%s/%s]. \
-                            Upgrading to a chronologically-older release may not work reliably and is not recommended. Falling back to \
-                            transport protocol version [%s].""",
+                            a chronologically-newer release with a numerically-older version compared to this node's version [%s/%s]. \
+                            Upgrading to this version from a chronologically-newer release may not work reliably and is not recommended. \
+                            Falling back to transport protocol version [%s].""",
                         handshakeRequest.releaseVersion,
                         handshakeRequest.transportVersion,
                         Build.current().version(),
@@ -216,9 +216,9 @@ public void testHandshakeResponseFromOlderNodeWithPatchedProtocol() throws Excep
                     Strings.format(
                         """
                             Negotiating transport handshake with remote node with version [%s/%s] received on [*] which appears to be from \
-                            a chronologically-older release with a numerically-newer version compared to this node's version [%s/%s]. \
-                            Upgrading to a chronologically-older release may not work reliably and is not recommended. Falling back to \
-                            transport protocol version [%s].""",
+                            a chronologically-newer release with a numerically-older version compared to this node's version [%s/%s]. \
+                            Upgrading to this version from a chronologically-newer release may not work reliably and is not recommended. \
+                            Falling back to transport protocol version [%s].""",
                         handshakeResponse.getReleaseVersion(),
                         handshakeResponse.getTransportVersion(),
                         Build.current().version(),