SERVER-53394 Make ShardingTaskExecutorPoolReplicaSetMatching default to disabled for mongod

(cherry picked from commit ac99b5cf6202e2941220a1f5f56b8223af1841e9)

12 files changed, 106 insertions, 2 deletions

diff --git a/buildscripts/resmokeconfig/suites/sharding_last_stable_mongos_and_mixed_shards.yml b/buildscripts/resmokeconfig/suites/sharding_last_stable_mongos_and_mixed_shards.yml
index 2cd6843cb66..020cac625db 100644
--- a/buildscripts/resmokeconfig/suites/sharding_last_stable_mongos_and_mixed_shards.yml
+++ b/buildscripts/resmokeconfig/suites/sharding_last_stable_mongos_and_mixed_shards.yml
@@ -173,6 +173,8 @@ selector:
   - jstests/sharding/ismaster.js
   # Uses the enableShardedIndexConsistencyCheck parameter which does not exist on 4.0.
   - jstests/sharding/kill_pinned_cursor.js
+  # Uses the ShardingTaskExecutorPoolReplicaSetMatching parameter which does not exist on 4.0.
+  - jstests/sharding/sharding_task_executor_pool_matching_policy.js
 executor:
   config:
     shell_options:
diff --git a/buildscripts/resmokeconfig/suites/sharding_rs_matching_disabled.yml b/buildscripts/resmokeconfig/suites/sharding_rs_matching_disabled.yml
index f159ca35e52..e687680e55b 100644
--- a/buildscripts/resmokeconfig/suites/sharding_rs_matching_disabled.yml
+++ b/buildscripts/resmokeconfig/suites/sharding_rs_matching_disabled.yml
@@ -3,6 +3,9 @@ test_kind: js_test
 selector:
   roots:
   - jstests/sharding/*.js
+  exclude_files:
+  # Skip tests that set the matching policy internally.
+  - jstests/sharding/sharding_task_executor_pool_matching_policy.js
 
 executor:
   config:
diff --git a/buildscripts/resmokeconfig/suites/sharding_rs_matching_match_busiest_node.yml b/buildscripts/resmokeconfig/suites/sharding_rs_matching_match_busiest_node.yml
index 5aefdbbe4ec..68ad82ff1d8 100644
--- a/buildscripts/resmokeconfig/suites/sharding_rs_matching_match_busiest_node.yml
+++ b/buildscripts/resmokeconfig/suites/sharding_rs_matching_match_busiest_node.yml
@@ -3,6 +3,9 @@ test_kind: js_test
 selector:
   roots:
   - jstests/sharding/*.js
+  exclude_files:
+  # Skip tests that set the matching policy internally.
+  - jstests/sharding/sharding_task_executor_pool_matching_policy.js
 
 executor:
   config:
diff --git a/etc/backports_required_for_multiversion_tests.yml b/etc/backports_required_for_multiversion_tests.yml
index be5c138cf31..d752f7a2f73 100644
--- a/etc/backports_required_for_multiversion_tests.yml
+++ b/etc/backports_required_for_multiversion_tests.yml
@@ -92,6 +92,8 @@ all:
     test_file: jstests/sharding/change_stream_empty_apply_ops.js
   - ticket: SERVER-43904
     test_file: jstests/replsets/election_handoff_skips_unelectable_nodes.js
+  - ticket: SERVER-53394
+    test_file: jstests/sharding/sharding_task_executor_pool_matching_policy.js
 
 # Tests that should only be excluded from particular suites should be listed under that suite.
 suites:
diff --git a/jstests/sharding/sharding_task_executor_pool_matching_policy.js b/jstests/sharding/sharding_task_executor_pool_matching_policy.js
new file mode 100644
index 00000000000..bb7341825af
--- /dev/null
+++ b/jstests/sharding/sharding_task_executor_pool_matching_policy.js
@@ -0,0 +1,55 @@
+// Tests that the ShardingTaskExecutorPoolReplicaSetMatchingPolicy is correctly set when the default
+// "automatic" value is used for the ShardingTaskExecutorPoolReplicaSetMatching parameter (on
+// mongos, "matchPrimaryNode" should be set; on mongod, the policy should be "disabled").
+
+(function() {
+"use strict";
+
+// Helper function to check the matching policy of a node, given the output of the connPoolStats
+// command run against the node and the expected policy.
+function checkSTEPReplicaSetMatchingPolicy(connPoolStats, expectedPolicy) {
+    assert("replicaSetMatchingStrategy" in connPoolStats);
+    let nodePolicy = connPoolStats["replicaSetMatchingStrategy"];
+    assert.eq(nodePolicy, expectedPolicy);
+}
+
+// Helper function that checks, given a connection to a mongo{s, d}, that the output value returned
+// by the "getParameter" command for the parameter "ShardingTaskExecutorPoolReplicaSetMatching"
+// is "automatic".
+function checkGetParameterOutputIsAuto(dbConn) {
+    const getParameterCommand = {getParameter: 1};
+    getParameterCommand["ShardingTaskExecutorPoolReplicaSetMatching"] = 1;
+    const result = assert.commandWorked(dbConn.adminCommand(getParameterCommand));
+    const value = result["ShardingTaskExecutorPoolReplicaSetMatching"];
+    assert.eq(value, "automatic");
+}
+
+// Setup test fixture; get connection to mongos and each mongod.
+let paramsDoc = {
+    mongosOptions: {setParameter: {ShardingTaskExecutorPoolReplicaSetMatching: "automatic"}},
+    shardOptions: {setParameter: {ShardingTaskExecutorPoolReplicaSetMatching: "automatic"}}
+};
+let st = new ShardingTest({shards: 2, mongos: 1, other: paramsDoc});
+let mongos = st.s;
+let mongod = st.shard0;
+let otherMongod = st.shard1;
+
+// Check that each connection currently has policy value "automatic"
+checkGetParameterOutputIsAuto(mongos);
+checkGetParameterOutputIsAuto(mongod);
+checkGetParameterOutputIsAuto(otherMongod);
+
+// Build connPoolStats command for each mongod and mongos; ensure they run without error.
+let mongosStats = mongos.adminCommand({connPoolStats: 1});
+let mongodStats = mongod.adminCommand({connPoolStats: 1});
+let otherMongodStats = otherMongod.adminCommand({connPoolStats: 1});
+assert.commandWorked(mongosStats);
+assert.commandWorked(mongodStats);
+assert.commandWorked(otherMongodStats);
+
+// Ensure the CPS contain the correct output (described in header comment for this test).
+checkSTEPReplicaSetMatchingPolicy(mongosStats, "matchPrimaryNode");
+checkSTEPReplicaSetMatchingPolicy(mongodStats, "disabled");
+checkSTEPReplicaSetMatchingPolicy(otherMongodStats, "disabled");
+st.stop();
+})();
diff --git a/src/mongo/executor/connection_pool.cpp b/src/mongo/executor/connection_pool.cpp
index 4b04c42a3ea..f812c8abc98 100644
--- a/src/mongo/executor/connection_pool.cpp
+++ b/src/mongo/executor/connection_pool.cpp
@@ -186,6 +186,8 @@ public:
         return "LimitController"_sd;
     }
 
+    void updateConnectionPoolStats(ConnectionPoolStats* cps) const override {}
+
 protected:
     struct PoolData {
         HostAndPort host;
@@ -557,6 +559,7 @@ SemiFuture<ConnectionPool::ConnectionHandle> ConnectionPool::get(const HostAndPo
 void ConnectionPool::appendConnectionStats(ConnectionPoolStats* stats) const {
     stdx::lock_guard lk(_mutex);
 
+    _controller->updateConnectionPoolStats(stats);
     for (const auto& kv : _pools) {
         HostAndPort host = kv.first;
 
diff --git a/src/mongo/executor/connection_pool.h b/src/mongo/executor/connection_pool.h
index d2f009d6859..750f045b2c0 100644
--- a/src/mongo/executor/connection_pool.h
+++ b/src/mongo/executor/connection_pool.h
@@ -472,6 +472,8 @@ public:
         return _pool;
     }
 
+    virtual void updateConnectionPoolStats([[maybe_unused]] ConnectionPoolStats* cps) const = 0;
+
 protected:
     ConnectionPool* _pool = nullptr;
 };
diff --git a/src/mongo/executor/connection_pool_stats.cpp b/src/mongo/executor/connection_pool_stats.cpp
index 31da4d38f96..5664d06ffd0 100644
--- a/src/mongo/executor/connection_pool_stats.cpp
+++ b/src/mongo/executor/connection_pool_stats.cpp
@@ -99,6 +99,10 @@ void ConnectionPoolStats::appendToBSON(mongo::BSONObjBuilder& result, bool forFT
     }
 
     {
+        if (strategy) {
+            result.append("replicaSetMatchingStrategy", matchingStrategyToString(*strategy));
+        }
+
         BSONObjBuilder poolBuilder(result.subobjStart("pools"));
         for (const auto& pool : statsByPool) {
             BSONObjBuilder poolInfo(poolBuilder.subobjStart(pool.first));
diff --git a/src/mongo/executor/connection_pool_stats.h b/src/mongo/executor/connection_pool_stats.h
index bfa9a771ac2..3f9235040eb 100644
--- a/src/mongo/executor/connection_pool_stats.h
+++ b/src/mongo/executor/connection_pool_stats.h
@@ -29,6 +29,7 @@
 
 #pragma once
 
+#include "mongo/s/sharding_task_executor_pool_controller.h"
 #include "mongo/stdx/unordered_map.h"
 #include "mongo/util/net/hostandport.h"
 
@@ -66,6 +67,7 @@ struct ConnectionPoolStats {
     size_t totalAvailable = 0u;
     size_t totalCreated = 0u;
     size_t totalRefreshing = 0u;
+    boost::optional<ShardingTaskExecutorPoolController::MatchingStrategy> strategy;
 
     using StatsByHost = std::map<HostAndPort, ConnectionStatsPer>;
 
diff --git a/src/mongo/s/sharding_task_executor_pool.idl b/src/mongo/s/sharding_task_executor_pool.idl
index 4a036162971..361ad6606ff 100644
--- a/src/mongo/s/sharding_task_executor_pool.idl
+++ b/src/mongo/s/sharding_task_executor_pool.idl
@@ -90,4 +90,4 @@ server_parameters:
     set_at: [ startup, runtime ]
     cpp_varname: "ShardingTaskExecutorPoolController::gParameters.matchingStrategyString"
     on_update: "ShardingTaskExecutorPoolController::onUpdateMatchingStrategy"
-    default: "matchPrimaryNode"
+    default: "automatic" # matchPrimaryNode on mongos; disabled on mongod
diff --git a/src/mongo/s/sharding_task_executor_pool_controller.cpp b/src/mongo/s/sharding_task_executor_pool_controller.cpp
index cc7b2197f48..8853f87b7df 100644
--- a/src/mongo/s/sharding_task_executor_pool_controller.cpp
+++ b/src/mongo/s/sharding_task_executor_pool_controller.cpp
@@ -32,6 +32,8 @@
 #include "mongo/platform/basic.h"
 
 #include "mongo/client/replica_set_monitor.h"
+#include "mongo/executor/connection_pool_stats.h"
+#include "mongo/s/is_mongos.h"
 #include "mongo/s/sharding_task_executor_pool_controller.h"
 #include "mongo/util/log.h"
 
@@ -83,7 +85,13 @@ Status ShardingTaskExecutorPoolController::validatePendingTimeout(const int& pen
 
 Status ShardingTaskExecutorPoolController::onUpdateMatchingStrategy(const std::string& str) {
     // TODO Fix up after SERVER-40224
-    if (str == "disabled") {
+    if (str == "automatic") {
+        if (isMongos()) {
+            gParameters.matchingStrategy.store(MatchingStrategy::kMatchPrimaryNode);
+        } else {
+            gParameters.matchingStrategy.store(MatchingStrategy::kDisabled);
+        }
+    } else if (str == "disabled") {
         gParameters.matchingStrategy.store(MatchingStrategy::kDisabled);
     } else if (str == "matchPrimaryNode") {
         gParameters.matchingStrategy.store(MatchingStrategy::kMatchPrimaryNode);
@@ -312,4 +320,9 @@ Milliseconds ShardingTaskExecutorPoolController::toRefreshTimeout() const {
     return Milliseconds{gParameters.toRefreshTimeoutMS.load()};
 }
 
+void ShardingTaskExecutorPoolController::updateConnectionPoolStats(
+    executor::ConnectionPoolStats* cps) const {
+    cps->strategy = gParameters.matchingStrategy.load();
+}
+
 }  // namespace mongo
diff --git a/src/mongo/s/sharding_task_executor_pool_controller.h b/src/mongo/s/sharding_task_executor_pool_controller.h
index 718c2b0cd0a..4cee10bd9f6 100644
--- a/src/mongo/s/sharding_task_executor_pool_controller.h
+++ b/src/mongo/s/sharding_task_executor_pool_controller.h
@@ -77,6 +77,19 @@ public:
         kMatchBusiestNode,
     };
 
+    friend StringData matchingStrategyToString(MatchingStrategy strategy) {
+        switch (strategy) {
+            case ShardingTaskExecutorPoolController::MatchingStrategy::kMatchPrimaryNode:
+                return "matchPrimaryNode"_sd;
+            case ShardingTaskExecutorPoolController::MatchingStrategy::kMatchBusiestNode:
+                return "matchBusiestNode"_sd;
+            case ShardingTaskExecutorPoolController::MatchingStrategy::kDisabled:
+                return "disabled"_sd;
+            default:
+                MONGO_UNREACHABLE;
+        }
+    }
+
     class Parameters {
     public:
         AtomicWord<int> minConnections;
@@ -129,6 +142,8 @@ public:
         return "ShardingTaskExecutorPoolController"_sd;
     }
 
+    void updateConnectionPoolStats(executor::ConnectionPoolStats* cps) const override;
+
 private:
     void _addGroup(WithLock, const ReplicaSetChangeNotifier::State& state);
     void _removeGroup(WithLock, const std::string& key);