Backport #51934 to 23.4: Fix async connect to hosts with multiple ips

src/Client/Connection.cpp

@@ -105,6 +105,8 @@ void Connection::connect(const ConnectionTimeouts & timeouts)
 
         for (auto it = addresses.begin(); it != addresses.end();)
         {
+            have_more_addresses_to_connect = it != std::prev(addresses.end());
+
             if (connected)
                 disconnect();
 

src/Client/Connection.h

@@ -159,6 +159,8 @@ class Connection : public IServerConnection
             out->setAsyncCallback(async_callback);
     }
 
+    bool haveMoreAddressesToConnect() const { return have_more_addresses_to_connect; }
+
 private:
     String host;
     UInt16 port;
@@ -227,6 +229,8 @@ class Connection : public IServerConnection
     std::shared_ptr<WriteBuffer> maybe_compressed_out;
     std::unique_ptr<NativeWriter> block_out;
 
+    bool have_more_addresses_to_connect = false;
+
     /// Logger is created lazily, for avoid to run DNS request in constructor.
     class LoggerWrapper
     {

src/Client/ConnectionEstablisher.cpp

@@ -174,7 +174,7 @@ bool ConnectionEstablisherAsync::checkTimeout()
             is_timeout_alarmed = true;
     }
 
-    if (is_timeout_alarmed && !is_socket_ready)
+    if (is_timeout_alarmed && !is_socket_ready && !haveMoreAddressesToConnect())
     {
         /// In not async case timeout exception would be thrown and caught in ConnectionEstablisher::run,
         /// but in async case we process timeout outside and cannot throw exception. So, we just save fail message.
@@ -220,6 +220,11 @@ void ConnectionEstablisherAsync::resetResult()
     }
 }
 
+bool ConnectionEstablisherAsync::haveMoreAddressesToConnect()
+{
+    return !result.entry.isNull() && result.entry->haveMoreAddressesToConnect();
+}
+
 #endif
 
 }

src/Client/ConnectionEstablisher.h

@@ -104,6 +104,8 @@ class ConnectionEstablisherAsync : public AsyncTaskExecutor
 
     void resetResult();
 
+    bool haveMoreAddressesToConnect();
+
     ConnectionEstablisher connection_establisher;
     TryResult result;
     std::string fail_message;

tests/integration/test_async_connect_to_multiple_ips/configs/enable_hedged.xml

@@ -0,0 +1,7 @@
+<clickhouse>
+    <profiles>
+        <default>
+            <use_hedged_requests>1</use_hedged_requests>
+        </default>
+    </profiles>
+</clickhouse>

tests/integration/test_async_connect_to_multiple_ips/configs/listen_host.xml

@@ -0,0 +1,4 @@
+<clickhouse>
+    <listen_host>::</listen_host>
+</clickhouse>
+

tests/integration/test_async_connect_to_multiple_ips/test.py

@@ -0,0 +1,72 @@
+import pytest
+from helpers.cluster import ClickHouseCluster
+
+
+cluster = ClickHouseCluster(__file__)
+
+
+@pytest.fixture(scope="module")
+def cluster_without_dns_cache_update():
+    try:
+        cluster.start()
+
+        yield cluster
+
+    except Exception as ex:
+        print(ex)
+
+    finally:
+        cluster.shutdown()
+        pass
+
+
+node1 = cluster.add_instance(
+    "node1",
+    main_configs=["configs/listen_host.xml"],
+    user_configs=["configs/enable_hedged.xml"],
+    with_zookeeper=True,
+    ipv4_address="10.5.95.11",
+)
+
+node2 = cluster.add_instance(
+    "node2",
+    main_configs=["configs/listen_host.xml"],
+    user_configs=["configs/enable_hedged.xml"],
+    with_zookeeper=True,
+    ipv4_address="10.5.95.12",
+)
+
+
+# node1 - source with table, have invalid ipv6
+# node2 - destination, doing remote query
+def test(cluster_without_dns_cache_update):
+    node1.query(
+        "CREATE TABLE test(t Date, label UInt8) ENGINE = MergeTree PARTITION BY t ORDER BY label;"
+    )
+    node1.query("INSERT INTO test SELECT toDate('2022-12-28'), 1;")
+    assert node1.query("SELECT count(*) FROM test") == "1\n"
+
+    wrong_ip = "2001:3984:3989::1:1118"
+
+    node2.exec_in_container(
+        (["bash", "-c", "echo '{} {}' >> /etc/hosts".format(wrong_ip, node1.name)])
+    )
+    node2.exec_in_container(
+        (
+            [
+                "bash",
+                "-c",
+                "echo '{} {}' >> /etc/hosts".format(node1.ipv4_address, node1.name),
+            ]
+        )
+    )
+
+    assert node1.query("SELECT count(*) from test") == "1\n"
+    node2.query("SYSTEM DROP DNS CACHE")
+    node1.query("SYSTEM DROP DNS CACHE")
+    assert (
+        node2.query(
+            f"SELECT count(*) FROM remote('{node1.name}', default.test) limit 1;"
+        )
+        == "1\n"
+    )