**Build scan:**
https://gradle-enterprise.elastic.co/s/4jzcubi7fi7fk/tests/:server:test/org.elasticsearch.transport.ProxyConnectionStrategyTests/testProxyStrategyWillResolveAddressesEachConnect

**Reproduction line:**
```
./gradlew ':server:test' --tests "org.elasticsearch.transport.ProxyConnectionStrategyTests.testProxyStrategyWillResolveAddressesEachConnect" -Dtests.seed=EA553A058C9E39DA -Dtests.locale=de-AT -Dtests.timezone=America/Maceio -Druntime.java=20
```

**Applicable branches:**
main

**Reproduces locally?:**
No

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.transport.ProxyConnectionStrategyTests&tests.test=testProxyStrategyWillResolveAddressesEachConnect

**Failure excerpt:**
```
com.carrotsearch.randomizedtesting.UncaughtExceptionError: Captured an uncaught exception in thread: Thread[id=2052, name=elasticsearch[org.elasticsearch.transport.ProxyConnectionStrategyTests][management][T#1], state=RUNNABLE, group=TGRP-ProxyConnectionStrategyTests]

  at __randomizedtesting.SeedInfo.seed([EA553A058C9E39DA:2A656647652A147E]:0)

  Caused by: java.lang.AssertionError: should not happen since onFailure should catch it and report with underlying cause

    at __randomizedtesting.SeedInfo.seed([EA553A058C9E39DA]:0)
    at org.elasticsearch.transport.ProxyConnectionStrategy.openConnections(ProxyConnectionStrategy.java:320)
    at org.elasticsearch.transport.ProxyConnectionStrategy$1.onFailure(ProxyConnectionStrategy.java:282)
    at org.elasticsearch.transport.ProxyConnectionStrategy.lambda$openConnections$10(ProxyConnectionStrategy.java:314)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.acceptException(ActionListenerImplementations.java:186)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.onFailure(ActionListenerImplementations.java:191)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.support.ContextPreservingActionListener.onFailure(ContextPreservingActionListener.java:39)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNodeOrRetry(ClusterConnectionManager.java:140)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNode(ClusterConnectionManager.java:111)
    at org.elasticsearch.transport.RemoteConnectionManager.connectToRemoteClusterNode(RemoteConnectionManager.java:73)
    at org.elasticsearch.transport.ProxyConnectionStrategy.openConnections(ProxyConnectionStrategy.java:309)
    at org.elasticsearch.transport.ProxyConnectionStrategy$1.onFailure(ProxyConnectionStrategy.java:282)
    at org.elasticsearch.transport.ProxyConnectionStrategy.lambda$openConnections$10(ProxyConnectionStrategy.java:314)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.acceptException(ActionListenerImplementations.java:186)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.onFailure(ActionListenerImplementations.java:191)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.support.ContextPreservingActionListener.onFailure(ContextPreservingActionListener.java:39)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNodeOrRetry(ClusterConnectionManager.java:140)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNode(ClusterConnectionManager.java:111)
    at org.elasticsearch.transport.RemoteConnectionManager.connectToRemoteClusterNode(RemoteConnectionManager.java:73)
    at org.elasticsearch.transport.ProxyConnectionStrategy.openConnections(ProxyConnectionStrategy.java:309)
    at org.elasticsearch.transport.ProxyConnectionStrategy$1.onFailure(ProxyConnectionStrategy.java:282)
    at org.elasticsearch.transport.ProxyConnectionStrategy.lambda$openConnections$10(ProxyConnectionStrategy.java:314)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.acceptException(ActionListenerImplementations.java:186)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingResponseActionListener.onFailure(ActionListenerImplementations.java:191)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.ActionListenerImplementations.safeAcceptException(ActionListenerImplementations.java:62)
    at org.elasticsearch.action.ActionListenerImplementations.safeOnFailure(ActionListenerImplementations.java:73)
    at org.elasticsearch.action.DelegatingActionListener.onFailure(DelegatingActionListener.java:27)
    at org.elasticsearch.action.support.ContextPreservingActionListener.onFailure(ContextPreservingActionListener.java:39)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNodeOrRetry(ClusterConnectionManager.java:140)
    at org.elasticsearch.transport.ClusterConnectionManager.connectToNode(ClusterConnectionManager.java:111)
    at org.elasticsearch.transport.RemoteConnectionManager.connectToRemoteClusterNode(RemoteConnectionManager.java:73)
    at org.elasticsearch.transport.ProxyConnectionStrategy.openConnections(ProxyConnectionStrategy.java:309)
    at org.elasticsearch.transport.ProxyConnectionStrategy.performProxyConnectionProcess(ProxyConnectionStrategy.java:241)
    at org.elasticsearch.transport.ProxyConnectionStrategy.connectImpl(ProxyConnectionStrategy.java:232)
    at org.elasticsearch.transport.RemoteConnectionStrategy$1.doRun(RemoteConnectionStrategy.java:296)
    at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:26)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:577)
    at java.util.concurrent.FutureTask.run(FutureTask.java:317)
    at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:916)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
    at java.lang.Thread.run(Thread.java:1623)

```
server/src/main/java/org/elasticsearch/transport/ProxyConnectionStrategy.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */
package org.elasticsearch.transport;
import org.elasticsearch.TransportVersions;
import org.elasticsearch.Version;
import org.elasticsearch.action.ActionListener;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.node.DiscoveryNodeRole;
import org.elasticsearch.cluster.node.VersionInformation;
import org.elasticsearch.common.Strings;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;