SERVER-41825 Remove FCV checks related to mutable shard key fields

2 files changed, 5 insertions, 291 deletions

diff --git a/jstests/multiVersion/update_shard_key_disallowed_fcv40.js b/jstests/multiVersion/update_shard_key_disallowed_fcv40.js
deleted file mode 100644
index ee7648679ab..00000000000
--- a/jstests/multiVersion/update_shard_key_disallowed_fcv40.js
+++ /dev/null
@@ -1,273 +0,0 @@
-// Test that shard key fields cannot be updated when one or more shards is in FCV 4.0.
-// @tags: [uses_transactions, uses_multi_shard_transaction]
-
-(function() {
-    "use strict";
-
-    load("jstests/libs/feature_compatibility_version.js");
-    load("jstests/sharding/libs/update_shard_key_helpers.js");
-
-    let st = new ShardingTest({
-        shards: {rs0: {nodes: 3, binVersion: "latest"}, rs1: {nodes: 3, binVersion: "latest"}},
-        mongos: 1,
-        other: {mongosOptions: {binVersion: "latest"}, configOptions: {binVersion: "latest"}}
-    });
-    let mongos = st.s0;
-    let kDbName = "test";
-    let collName = "foo";
-    let ns = kDbName + "." + collName;
-
-    assert.commandWorked(mongos.adminCommand({enableSharding: kDbName}));
-    st.ensurePrimaryShard(kDbName, st.shard0.shardName);
-
-    function shardCollectionAndMoveChunks(docsToInsert, shardKey, splitDoc, moveDoc) {
-        for (let i = 0; i < docsToInsert.length; i++) {
-            assert.commandWorked(mongos.getDB(kDbName).foo.insert(docsToInsert[i]));
-        }
-
-        assert.commandWorked(mongos.getDB(kDbName).foo.createIndex(shardKey));
-        assert.commandWorked(mongos.adminCommand({shardCollection: ns, key: shardKey}));
-        assert.commandWorked(mongos.adminCommand({split: ns, find: splitDoc}));
-        assert.commandWorked(
-            mongos.adminCommand({moveChunk: ns, find: moveDoc, to: st.shard1.shardName}));
-
-        assert.commandWorked(mongos.adminCommand({flushRouterConfig: 1}));
-        st.rs0.getPrimary().adminCommand({_flushRoutingTableCacheUpdates: ns});
-        st.rs1.getPrimary().adminCommand({_flushRoutingTableCacheUpdates: ns});
-        st.rs0.getPrimary().adminCommand({_flushDatabaseCacheUpdates: kDbName});
-        st.rs1.getPrimary().adminCommand({_flushDatabaseCacheUpdates: kDbName});
-    }
-
-    function assertCannotUpdateShardKey(isMixedCluster) {
-        // ------------------------------------------------
-        // Test changes to shard key run as retryable write
-        // ------------------------------------------------
-        let session = st.s.startSession({retryWrites: true});
-        let sessionDB = session.getDatabase(kDbName);
-
-        // Updates to full shard key
-        shardCollectionMoveChunks(
-            st, kDbName, ns, {x: 1}, [{x: 30}, {x: 50}, {x: 80}], {x: 50}, {x: 80});
-        cleanupOrphanedDocs(st, ns);
-
-        // Assert that updating the shard key when the doc would remain on the same shard fails for
-        // both modify and replacement updates
-        assert.writeError(sessionDB.foo.update({x: 80}, {$set: {x: 100}}));
-        assert.writeError(sessionDB.foo.update({x: 80}, {x: 100}));
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {$set: {x: 100}}});
-        });
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {x: 100}});
-        });
-
-        // Assert that updating the shard key when the doc would move shards fails for both modify
-        // and replacement updates.
-        assert.writeError(sessionDB.foo.update({x: 80}, {$set: {x: 3}}));
-        assert.commandFailedWithCode(sessionDB.foo.update({x: 80}, {x: 3}),
-                                     [ErrorCodes.ImmutableField, ErrorCodes.InvalidOptions]);
-        assert.eq(1, mongos.getDB(kDbName).foo.find({x: 80}).itcount());
-        assert.eq(0, mongos.getDB(kDbName).foo.find({x: 3}).itcount());
-
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {$set: {x: 3}}});
-        });
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {x: 3}});
-        });
-
-        mongos.getDB(kDbName).foo.drop();
-
-        // Updates to partial shard key
-        shardCollectionMoveChunks(st,
-                                  kDbName,
-                                  ns,
-                                  {x: 1, y: 1},
-                                  [{x: 30, y: 4}, {x: 50, y: 50}, {x: 80, y: 100}],
-                                  {x: 50, y: 50},
-                                  {x: 80, y: 100});
-        cleanupOrphanedDocs(st, ns);
-
-        // Assert that updating the shard key when the doc would remain on the same shard fails for
-        // both modify and replacement updates
-        assert.writeError(sessionDB.foo.update({x: 80}, {$set: {x: 100}}));
-        assert.writeError(sessionDB.foo.update({x: 80}, {x: 100}));
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {$set: {x: 100}}});
-        });
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {x: 100}});
-        });
-
-        // Assert that updating the shard key when the doc would move shards fails for both modify
-        // and replacement updates
-        assert.writeError(sessionDB.foo.update({x: 80}, {$set: {x: 3}}));
-        assert.writeError(sessionDB.foo.update({x: 80}, {x: 3}));
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {$set: {x: 3}}});
-        });
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {x: 3}});
-        });
-
-        mongos.getDB(kDbName).foo.drop();
-
-        // -----------------------------------------------
-        // Test changes to shard key run in a transaction
-        // -----------------------------------------------
-        session = st.s.startSession();
-        sessionDB = session.getDatabase(kDbName);
-
-        // Updates to full shard key
-        shardCollectionMoveChunks(
-            st, kDbName, ns, {x: 1}, [{x: 30}, {x: 50}, {x: 80}], {x: 50}, {x: 80});
-        cleanupOrphanedDocs(st, ns);
-
-        // Assert that updating the shard key when the doc would remain on the same shard fails for
-        // both modify and replacement updates
-        session.startTransaction();
-        assert.writeError(sessionDB.foo.update({x: 80}, {$set: {x: 100}}));
-        assert.commandFailedWithCode(session.abortTransaction_forTesting(),
-                                     ErrorCodes.NoSuchTransaction);
-
-        session.startTransaction();
-        assert.throws(function() {
-            sessionDB.foo.findAndModify({query: {x: 80}, update: {x: 100}});
-        });
-        assert.commandFailedWithCode(session.abortTransaction_forTesting(),
-                                     ErrorCodes.NoSuchTransaction);
-
-        mongos.getDB(kDbName).foo.drop();
-
-        if (isMixedCluster) {
-            // Assert that updating the shard key when the doc would move shards fails on commit
-            // because one of the participants is not in FCV 4.2. If the original write is a
-            // retryable write, the write will fail when mongos attempts to run commitTransaction.
-            // If the original write is part of a transaction, the write itself will complete
-            // successfully, but the transaction will fail to commit.
-
-            // Retryable write - updates to full shard key
-            session = st.s.startSession({retryWrites: true});
-            sessionDB = session.getDatabase(kDbName);
-
-            shardCollectionMoveChunks(
-                st, kDbName, ns, {x: 1}, [{x: 30}, {x: 50}, {x: 80}], {x: 50}, {x: 80});
-            cleanupOrphanedDocs(st, ns);
-
-            // Doc will move shards
-            assert.writeError(sessionDB.foo.update({x: 30}, {$set: {x: 100}}));
-            assert.throws(function() {
-                sessionDB.foo.findAndModify({query: {x: 30}, update: {$set: {x: 100}}});
-            });
-
-            // Doc will remain on the same shard. Because shard 0 is on FCV 4.2, these should
-            // complete successfully.
-            sessionDB.foo.findAndModify({query: {x: 30}, update: {$set: {x: 5}}});
-            st.rs0.awaitReplication();
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 30}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 30}).itcount());
-
-            sessionDB.foo.findAndModify({query: {x: 5}, update: {x: 10}});
-            st.rs0.awaitReplication();
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 10}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 10}).itcount());
-
-            assert.commandWorked(sessionDB.foo.update({x: 10}, {$set: {x: 25}}));
-            st.rs0.awaitReplication();
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 25}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 25}).itcount());
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 10}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 10}).itcount());
-
-            assert.commandWorked(sessionDB.foo.update({x: 25}, {x: 3}));
-            st.rs0.awaitReplication();
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 25}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 25}).itcount());
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 3}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 3}).itcount());
-
-            mongos.getDB(kDbName).foo.drop();
-
-            // Retryable write - updates to partial shard key
-            shardCollectionMoveChunks(st,
-                                      kDbName,
-                                      ns,
-                                      {x: 1, y: 1},
-                                      [{x: 30, y: 4}, {x: 50, y: 50}, {x: 80, y: 100}],
-                                      {x: 50, y: 50},
-                                      {x: 80, y: 100});
-            cleanupOrphanedDocs(st, ns);
-
-            assert.writeError(sessionDB.foo.update({x: 30}, {$set: {x: 100}}));
-            assert.throws(function() {
-                sessionDB.foo.findAndModify({query: {x: 30}, update: {x: 100}});
-            });
-
-            mongos.getDB(kDbName).foo.drop();
-
-            // Transactional writes
-            session = st.s.startSession();
-            sessionDB = session.getDatabase(kDbName);
-
-            shardCollectionMoveChunks(
-                st, kDbName, ns, {x: 1}, [{x: 10}, {x: 30}, {x: 50}, {x: 80}], {x: 50}, {x: 80});
-            cleanupOrphanedDocs(st, ns);
-
-            session.startTransaction();
-            assert.commandWorked(sessionDB.foo.update({x: 30}, {$set: {x: 100}}));
-            assert.commandFailed(session.commitTransaction_forTesting());
-
-            assert.eq(1, mongos.getDB(kDbName).foo.find({x: 30}).itcount());
-            assert.eq(0, mongos.getDB(kDbName).foo.find({x: 100}).itcount());
-
-            session.startTransaction();
-            sessionDB.foo.findAndModify({query: {x: 30}, update: {x: 100}});
-            assert.commandFailed(session.commitTransaction_forTesting());
-
-            assert.eq(1, mongos.getDB(kDbName).foo.find({x: 30}).itcount());
-            assert.eq(0, mongos.getDB(kDbName).foo.find({x: 100}).itcount());
-
-            // Doc will remain on the same shard. Because shard 0 is on FCV 4.2, this should
-            // complete successfully.
-            session.startTransaction();
-            sessionDB.foo.findAndModify({query: {x: 10}, update: {x: 1}});
-            assert.commandWorked(sessionDB.foo.update({x: 30}, {$set: {x: 5}}));
-            assert.commandWorked(session.commitTransaction_forTesting());
-            st.rs0.awaitReplication();
-
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 30}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 30}).itcount());
-            assert.eq(0, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 10}).itcount());
-            assert.eq(0, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 10}).itcount());
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 5}).itcount());
-            assert.eq(1, st.rs0.getPrimary().getDB(kDbName).foo.find({x: 1}).itcount());
-            assert.eq(1, st.rs0.getSecondaries()[0].getDB(kDbName).foo.find({x: 1}).itcount());
-
-            mongos.getDB(kDbName).foo.drop();
-        }
-    }
-
-    // Check that updating the shard key fails when all shards are in FCV 4.0
-    assert.commandWorked(st.s.getDB("admin").runCommand({setFeatureCompatibilityVersion: "4.0"}));
-    checkFCV(st.configRS.getPrimary().getDB("admin"), "4.0");
-    checkFCV(st.rs0.getPrimary().getDB("admin"), "4.0");
-    checkFCV(st.rs1.getPrimary().getDB("admin"), "4.0");
-
-    assertCannotUpdateShardKey(false);
-
-    // Check that updating the shard key fails when shard0 is in FCV 4.2 but shard 1 is in FCV 4.0
-    assert.commandWorked(
-        st.rs0.getPrimary().getDB("admin").runCommand({setFeatureCompatibilityVersion: "4.2"}));
-    checkFCV(st.configRS.getPrimary().getDB("admin"), "4.0");
-    checkFCV(st.rs0.getPrimary().getDB("admin"), "4.2");
-    checkFCV(st.rs1.getPrimary().getDB("admin"), "4.0");
-
-    assertCannotUpdateShardKey(true);
-
-    st.stop();
-})();
diff --git a/src/mongo/db/exec/update_stage.cpp b/src/mongo/db/exec/update_stage.cpp
index 7f079f27d9f..85bce89da40 100644
--- a/src/mongo/db/exec/update_stage.cpp
+++ b/src/mongo/db/exec/update_stage.cpp
@@ -213,10 +213,6 @@ BSONObj UpdateStage::transformAndUpdate(const Snapshotted<BSONObj>& oldObj, Reco
 
     bool docWasModified = false;
 
-    const auto isFCV42 = serverGlobalParams.featureCompatibility.isVersionInitialized() &&
-        serverGlobalParams.featureCompatibility.getVersion() ==
-            ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo42;
-
     auto* const css = CollectionShardingState::get(getOpCtx(), collection()->ns());
     auto metadata = css->getCurrentMetadata();
     Status status = Status::OK();
@@ -224,8 +220,7 @@ BSONObj UpdateStage::transformAndUpdate(const Snapshotted<BSONObj>& oldObj, Reco
     const bool isInsert = false;
     FieldRefSet immutablePaths;
     if (getOpCtx()->writesAreReplicated() && !request->isFromMigration()) {
-        if (metadata->isSharded() &&
-            (!OperationShardingState::isOperationVersioned(getOpCtx()) || !isFCV42)) {
+        if (metadata->isSharded() && !OperationShardingState::isOperationVersioned(getOpCtx())) {
             auto& immutablePathsVector = metadata->getKeyPatternFields();
             immutablePaths.fillFrom(
                 transitional_tools_do_not_use::unspool_vector(immutablePathsVector));
@@ -323,7 +318,7 @@ BSONObj UpdateStage::transformAndUpdate(const Snapshotted<BSONObj>& oldObj, Reco
 
                 Snapshotted<RecordData> snap(oldObj.snapshotId(), oldRec);
 
-                if (isFCV42 && metadata->isSharded() && _shouldCheckForShardKeyUpdate) {
+                if (metadata->isSharded() && _shouldCheckForShardKeyUpdate) {
                     bool changesShardKeyOnSameNode =
                         checkUpdateChangesShardKeyFields(metadata, oldObj);
                     if (changesShardKeyOnSameNode && !args.preImageDoc) {
@@ -351,7 +346,7 @@ BSONObj UpdateStage::transformAndUpdate(const Snapshotted<BSONObj>& oldObj, Reco
                     newObj.objsize() <= BSONObjMaxUserSize);
 
             if (!request->isExplain()) {
-                if (isFCV42 && metadata->isSharded() && _shouldCheckForShardKeyUpdate) {
+                if (metadata->isSharded() && _shouldCheckForShardKeyUpdate) {
                     bool changesShardKeyOnSameNode =
                         checkUpdateChangesShardKeyFields(metadata, oldObj);
                     if (changesShardKeyOnSameNode && !args.preImageDoc) {
@@ -412,13 +407,8 @@ BSONObj UpdateStage::applyUpdateOpsForInsert(OperationContext* opCtx,
     auto* const css = CollectionShardingState::get(opCtx, ns);
     auto metadata = css->getCurrentMetadata();
 
-    const auto isFCV42 = serverGlobalParams.featureCompatibility.isVersionInitialized() &&
-        serverGlobalParams.featureCompatibility.getVersion() ==
-            ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo42;
-
     FieldRefSet immutablePaths;
-    if (metadata->isSharded() &&
-        (!OperationShardingState::isOperationVersioned(opCtx) || !isFCV42)) {
+    if (metadata->isSharded() && !OperationShardingState::isOperationVersioned(opCtx)) {
         auto& immutablePathsVector = metadata->getKeyPatternFields();
         immutablePaths.fillFrom(
             transitional_tools_do_not_use::unspool_vector(immutablePathsVector));
@@ -594,13 +584,10 @@ void UpdateStage::doInsert() {
     // fields in the 'q' field belong to this shard, but those in the 'u' field do not. In this case
     // we need to throw so that MongoS can target the insert to the correct shard.
     if (_shouldCheckForShardKeyUpdate) {
-        const auto isFCV42 = serverGlobalParams.featureCompatibility.isVersionInitialized() &&
-            serverGlobalParams.featureCompatibility.getVersion() ==
-                ServerGlobalParams::FeatureCompatibility::Version::kFullyUpgradedTo42;
         auto* const css = CollectionShardingState::get(getOpCtx(), collection()->ns());
         const auto& metadata = css->getCurrentMetadata();
 
-        if (isFCV42 && metadata->isSharded()) {
+        if (metadata->isSharded()) {
             const ShardKeyPattern shardKeyPattern(metadata->getKeyPattern());
             auto newShardKey = shardKeyPattern.extractShardKeyFromDoc(newObj);