SERVER-58207 Enable featureFlagLoadBalancer by default

(cherry picked from commit 2b8743e84908d82dc4c5d69f636e853eda4bdadb)

7 files changed, 11 insertions, 19 deletions

diff --git a/jstests/sharding/load_balancer_support/disconnect_aborts_txns.js b/jstests/sharding/load_balancer_support/disconnect_aborts_txns.js
index 4758fede24f..151fc4b704c 100644
--- a/jstests/sharding/load_balancer_support/disconnect_aborts_txns.js
+++ b/jstests/sharding/load_balancer_support/disconnect_aborts_txns.js
@@ -1,6 +1,6 @@
 /**
- * @tags: [featureFlagLoadBalancer, uses_transactions, uses_multi_shard_transaction,
- * requires_sharding, requires_fcv_51]
+ * @tags: [uses_transactions, uses_multi_shard_transaction,
+ * requires_sharding, requires_fcv_53]
  *
  * Tests that when a load-balanced client disconnects, its in-progress transactions are aborted
  */
diff --git a/jstests/sharding/load_balancer_support/disconnect_kills_cursors.js b/jstests/sharding/load_balancer_support/disconnect_kills_cursors.js
index 270fedcccb1..3018eab76d6 100644
--- a/jstests/sharding/load_balancer_support/disconnect_kills_cursors.js
+++ b/jstests/sharding/load_balancer_support/disconnect_kills_cursors.js
@@ -1,5 +1,5 @@
 /**
- * @tags: [requires_fcv_51, featureFlagLoadBalancer]
+ * @tags: [requires_fcv_53]
  *
  * Tests that when a load-balanced client disconnects, its cursors are killed.
  */
diff --git a/jstests/sharding/load_balancer_support/load_balanced_server_status_metrics.js b/jstests/sharding/load_balancer_support/load_balanced_server_status_metrics.js
index 878eb60f448..3e19436a975 100644
--- a/jstests/sharding/load_balancer_support/load_balanced_server_status_metrics.js
+++ b/jstests/sharding/load_balancer_support/load_balanced_server_status_metrics.js
@@ -1,5 +1,5 @@
 /**
- * @tags: [requires_fcv_51, featureFlagLoadBalancer]
+ * @tags: [requires_fcv_53]
  *
  * Tests that load-balanced connections are reported correctly in server status metrics.
  */
diff --git a/jstests/sharding/load_balancer_support/load_balancer_hello.js b/jstests/sharding/load_balancer_support/load_balancer_hello.js
index 53aaffc2ecd..555911958b6 100644
--- a/jstests/sharding/load_balancer_support/load_balancer_hello.js
+++ b/jstests/sharding/load_balancer_support/load_balancer_hello.js
@@ -1,5 +1,5 @@
 /**
- * @tags: [requires_fcv_51, featureFlagLoadBalancer]
+ * @tags: [requires_fcv_53]
  *
  * Test the extension to the mongos `hello` command by which clients
  * that have arrived through a load balancer affirm that they are
diff --git a/jstests/sharding/proxy_protocol_connect.js b/jstests/sharding/proxy_protocol_connect.js
index 9afbed08dff..8e1f4033c9f 100644
--- a/jstests/sharding/proxy_protocol_connect.js
+++ b/jstests/sharding/proxy_protocol_connect.js
@@ -18,12 +18,8 @@ function testProxyProtocolConnect(ingressPort, egressPort, version) {
     let proxy_server = new ProxyProtocolServer(ingressPort, egressPort, version);
     proxy_server.start();
 
-    let st = new ShardingTest({
-        shards: 1,
-        mongos: 1,
-        mongosOptions:
-            {setParameter: {"featureFlagLoadBalancer": true, "loadBalancerPort": egressPort}}
-    });
+    let st = new ShardingTest(
+        {shards: 1, mongos: 1, mongosOptions: {setParameter: {"loadBalancerPort": egressPort}}});
 
     const uri = `mongodb://127.0.0.1:${ingressPort}/?loadBalanced=true`;
     const conn = new Mongo(uri);
@@ -37,11 +33,8 @@ function testProxyProtocolConnect(ingressPort, egressPort, version) {
 function testProxyProtocolConnectFailure(lbPort, sendLoadBalanced) {
     'use strict';
 
-    let st = new ShardingTest({
-        shards: 1,
-        mongos: 1,
-        mongosOptions: {setParameter: {"featureFlagLoadBalancer": true, "loadBalancerPort": lbPort}}
-    });
+    let st = new ShardingTest(
+        {shards: 1, mongos: 1, mongosOptions: {setParameter: {"loadBalancerPort": lbPort}}});
 
     const hostName = st.s.host.substring(0, st.s.host.indexOf(":"));
     const uri = `mongodb://${hostName}:${lbPort}/?loadBalanced=${sendLoadBalanced}`;
diff --git a/src/mongo/s/load_balancer_feature_flag.idl b/src/mongo/s/load_balancer_feature_flag.idl
index 1e99e15101b..d7f3c972ac0 100644
--- a/src/mongo/s/load_balancer_feature_flag.idl
+++ b/src/mongo/s/load_balancer_feature_flag.idl
@@ -38,4 +38,5 @@ feature_flags:
     featureFlagLoadBalancer:
         description: Feature flag for enabling L4 load balancer support.
         cpp_varname: gFeatureFlagLoadBalancer
-        default: false
+        default: true
+        version: 5.3 
diff --git a/src/mongo/s/load_balancer_support_test.cpp b/src/mongo/s/load_balancer_support_test.cpp
index f04bc28ff69..a5813346671 100644
--- a/src/mongo/s/load_balancer_support_test.cpp
+++ b/src/mongo/s/load_balancer_support_test.cpp
@@ -76,8 +76,6 @@ public:
     FailPointEnableBlock simulateLoadBalancerConnection() const {
         return FailPointEnableBlock("clientIsFromLoadBalancer");
     }
-
-    RAIIServerParameterControllerForTest featureEnabler{"featureFlagLoadBalancer", true};
 };
 
 TEST_F(LoadBalancerSupportTest, HelloNormalClientNoOption) {