SERVER-23096 Move initialization of config.version and the config db indexes to the config server

24 files changed, 753 insertions, 831 deletions

diff --git a/src/mongo/base/error_codes.err b/src/mongo/base/error_codes.err
index dbbe5d6aae2..191ce652127 100644
--- a/src/mongo/base/error_codes.err
+++ b/src/mongo/base/error_codes.err
@@ -130,7 +130,7 @@ error_code("LockNotFound", 128)
 error_code("LockStateChangeFailed", 129)
 error_code("SymbolNotFound", 130)
 error_code("RLPInitializationFailed", 131)
-error_code("ConfigServersInconsistent", 132)
+error_code("OBSOLETE_ConfigServersInconsistent", 132)
 error_code("FailedToSatisfyReadPreference", 133)
 error_code("ReadConcernMajorityNotAvailableYet", 134)
 error_code("StaleTerm", 135)
diff --git a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
index 496f26cc96a..f2227103413 100644
--- a/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_external_state_impl.cpp
@@ -69,6 +69,7 @@
 #include "mongo/executor/network_interface_factory.h"
 #include "mongo/executor/thread_pool_task_executor.h"
 #include "mongo/s/balancer/balancer.h"
+#include "mongo/s/catalog/sharding_catalog_manager.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/grid.h"
 #include "mongo/stdx/functional.h"
@@ -470,6 +471,21 @@ void ReplicationCoordinatorExternalStateImpl::shardingOnDrainingStateHook(Operat
     }
 
     if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
+        status = Grid::get(txn)->catalogManager()->initializeConfigDatabaseIfNeeded(txn);
+        if (!status.isOK()) {
+            if (status == ErrorCodes::ShutdownInProgress ||
+                status == ErrorCodes::InterruptedAtShutdown) {
+                // Don't fassert if we're mid-shutdown, let the shutdown happen gracefully.
+                return;
+            }
+            fassertFailedWithStatus(40184,
+                                    Status(status.code(),
+                                           str::stream()
+                                               << "Failed to initialize config database on config "
+                                                  "server's first transition to primary"
+                                               << causedBy(status)));
+        }
+
         // If this is a config server node becoming a primary, start the balancer
         auto balancer = Balancer::get(txn);
 
diff --git a/src/mongo/s/catalog/replset/SConscript b/src/mongo/s/catalog/replset/SConscript
index ec9157368fe..b741d44dc4c 100644
--- a/src/mongo/s/catalog/replset/SConscript
+++ b/src/mongo/s/catalog/replset/SConscript
@@ -109,6 +109,7 @@ env.CppUnitTest(
     source=[
         'sharding_catalog_add_shard_to_zone_test.cpp',
         'sharding_catalog_remove_shard_from_zone_test.cpp',
+        'sharding_catalog_config_initialization_test.cpp',
     ],
     LIBDEPS=[
         '$BUILD_DIR/mongo/db/repl/replmocks',
@@ -126,7 +127,6 @@ env.CppUnitTest(
         'sharding_catalog_remove_shard_test.cpp',
         'sharding_catalog_shard_collection_test.cpp',
         'sharding_catalog_test.cpp',
-        'sharding_catalog_upgrade_test.cpp',
         'sharding_catalog_write_retry_test.cpp',
     ],
     LIBDEPS=[
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_client_impl.cpp b/src/mongo/s/catalog/replset/sharding_catalog_client_impl.cpp
index ae8801ebbe9..53464281c65 100644
--- a/src/mongo/s/catalog/replset/sharding_catalog_client_impl.cpp
+++ b/src/mongo/s/catalog/replset/sharding_catalog_client_impl.cpp
@@ -54,12 +54,10 @@
 #include "mongo/executor/task_executor.h"
 #include "mongo/rpc/get_status_from_command_result.h"
 #include "mongo/rpc/metadata/repl_set_metadata.h"
-#include "mongo/s/catalog/config_server_version.h"
 #include "mongo/s/catalog/dist_lock_manager.h"
 #include "mongo/s/catalog/type_changelog.h"
 #include "mongo/s/catalog/type_chunk.h"
 #include "mongo/s/catalog/type_collection.h"
-#include "mongo/s/catalog/type_config_version.h"
 #include "mongo/s/catalog/type_database.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/catalog/type_tags.h"
@@ -101,7 +99,6 @@ const char kWriteConcernField[] = "writeConcern";
 const ReadPreferenceSetting kConfigReadSelector(ReadPreference::Nearest, TagSet{});
 const ReadPreferenceSetting kConfigPrimaryPreferredSelector(ReadPreference::PrimaryPreferred,
                                                             TagSet{});
-const int kMaxConfigVersionInitRetry = 3;
 const int kMaxReadRetry = 3;
 const int kMaxWriteRetry = 3;
 
@@ -1186,7 +1183,7 @@ Status ShardingCatalogClientImpl::applyChunkOpsDeprecated(OperationContext* txn,
                                                           const ChunkVersion& lastChunkVersion) {
     BSONObj cmd =
         BSON("applyOps" << updateOps << "preCondition" << preCondition << kWriteConcernField
-                        << kMajorityWriteConcern.toBSON());
+                        << ShardingCatalogClient::kMajorityWriteConcern.toBSON());
 
     auto response = Grid::get(txn)->shardRegistry()->getConfigShard()->runCommand(
         txn,
@@ -1555,107 +1552,6 @@ StatusWith<long long> ShardingCatalogClientImpl::_runCountCommandOnConfig(Operat
     return result;
 }
 
-Status ShardingCatalogClientImpl::initConfigVersion(OperationContext* txn) {
-    for (int x = 0; x < kMaxConfigVersionInitRetry; x++) {
-        auto versionStatus = _getConfigVersion(txn);
-        if (!versionStatus.isOK()) {
-            return versionStatus.getStatus();
-        }
-
-        auto versionInfo = versionStatus.getValue();
-        if (versionInfo.getMinCompatibleVersion() > CURRENT_CONFIG_VERSION) {
-            return {ErrorCodes::IncompatibleShardingConfigVersion,
-                    str::stream() << "current version v" << CURRENT_CONFIG_VERSION
-                                  << " is older than the cluster min compatible v"
-                                  << versionInfo.getMinCompatibleVersion()};
-        }
-
-        if (versionInfo.getCurrentVersion() == UpgradeHistory_EmptyVersion) {
-            VersionType newVersion;
-            newVersion.setClusterId(OID::gen());
-            newVersion.setMinCompatibleVersion(MIN_COMPATIBLE_CONFIG_VERSION);
-            newVersion.setCurrentVersion(CURRENT_CONFIG_VERSION);
-
-            BSONObj versionObj(newVersion.toBSON());
-            auto upsertStatus = updateConfigDocument(txn,
-                                                     VersionType::ConfigNS,
-                                                     versionObj,
-                                                     versionObj,
-                                                     true,
-                                                     ShardingCatalogClient::kMajorityWriteConcern);
-
-            if ((upsertStatus.isOK() && !upsertStatus.getValue()) ||
-                upsertStatus == ErrorCodes::DuplicateKey) {
-                // Do the check again as someone inserted a new config version document
-                // and the upsert neither inserted nor updated a config version document.
-                // Note: you can get duplicate key errors on upsert because of SERVER-14322.
-                continue;
-            }
-
-            return upsertStatus.getStatus();
-        }
-
-        if (versionInfo.getCurrentVersion() == UpgradeHistory_UnreportedVersion) {
-            return {ErrorCodes::IncompatibleShardingConfigVersion,
-                    "Assuming config data is old since the version document cannot be found in the "
-                    "config server and it contains databases aside 'local' and 'admin'. "
-                    "Please upgrade if this is the case. Otherwise, make sure that the config "
-                    "server is clean."};
-        }
-
-        if (versionInfo.getCurrentVersion() < CURRENT_CONFIG_VERSION) {
-            return {ErrorCodes::IncompatibleShardingConfigVersion,
-                    str::stream() << "need to upgrade current cluster version to v"
-                                  << CURRENT_CONFIG_VERSION
-                                  << "; currently at v"
-                                  << versionInfo.getCurrentVersion()};
-        }
-
-        return Status::OK();
-    }
-
-    return {ErrorCodes::IncompatibleShardingConfigVersion,
-            str::stream() << "unable to create new config version document after "
-                          << kMaxConfigVersionInitRetry
-                          << " retries"};
-}
-
-StatusWith<VersionType> ShardingCatalogClientImpl::_getConfigVersion(OperationContext* txn) {
-    auto findStatus = _exhaustiveFindOnConfig(txn,
-                                              kConfigReadSelector,
-                                              NamespaceString(VersionType::ConfigNS),
-                                              BSONObj(),
-                                              BSONObj(),
-                                              boost::none /* no limit */);
-    if (!findStatus.isOK()) {
-        return findStatus.getStatus();
-    }
-
-    auto queryResults = findStatus.getValue().value;
-
-    if (queryResults.size() > 1) {
-        return {ErrorCodes::RemoteValidationError,
-                str::stream() << "should only have 1 document in " << VersionType::ConfigNS};
-    }
-
-    if (queryResults.empty()) {
-        VersionType versionInfo;
-        versionInfo.setMinCompatibleVersion(UpgradeHistory_EmptyVersion);
-        versionInfo.setCurrentVersion(UpgradeHistory_EmptyVersion);
-        return versionInfo;
-    }
-
-    BSONObj versionDoc = queryResults.front();
-    auto versionTypeResult = VersionType::fromBSON(versionDoc);
-    if (!versionTypeResult.isOK()) {
-        return Status(ErrorCodes::UnsupportedFormat,
-                      str::stream() << "invalid config version document: " << versionDoc
-                                    << versionTypeResult.getStatus().toString());
-    }
-
-    return versionTypeResult.getValue();
-}
-
 StatusWith<repl::OpTimeWith<vector<BSONObj>>> ShardingCatalogClientImpl::_exhaustiveFindOnConfig(
     OperationContext* txn,
     const ReadPreferenceSetting& readPref,
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_client_impl.h b/src/mongo/s/catalog/replset/sharding_catalog_client_impl.h
index 8607e31c824..9d9d060a8e8 100644
--- a/src/mongo/s/catalog/replset/sharding_catalog_client_impl.h
+++ b/src/mongo/s/catalog/replset/sharding_catalog_client_impl.h
@@ -174,8 +174,6 @@ public:
 
     DistLockManager* getDistLockManager() override;
 
-    Status initConfigVersion(OperationContext* txn) override;
-
     Status appendInfoForConfigServerDatabases(OperationContext* txn,
                                               BSONArrayBuilder* builder) override;
 
@@ -245,11 +243,6 @@ private:
     void _appendReadConcern(BSONObjBuilder* builder);
 
     /**
-     * Returns the current cluster schema/protocol version.
-     */
-    StatusWith<VersionType> _getConfigVersion(OperationContext* txn);
-
-    /**
      * Queries the config servers for the database metadata for the given database, using the
      * given read preference.  Returns NamespaceNotFound if no database metadata is found.
      */
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_config_initialization_test.cpp b/src/mongo/s/catalog/replset/sharding_catalog_config_initialization_test.cpp
new file mode 100644
index 00000000000..ca4f04bda77
--- /dev/null
+++ b/src/mongo/s/catalog/replset/sharding_catalog_config_initialization_test.cpp
@@ -0,0 +1,322 @@
+/**
+ *    Copyright (C) 2015 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include <string>
+#include <vector>
+
+#include "mongo/bson/json.h"
+#include "mongo/db/namespace_string.h"
+#include "mongo/s/catalog/config_server_version.h"
+#include "mongo/s/catalog/sharding_catalog_manager.h"
+#include "mongo/s/catalog/type_chunk.h"
+#include "mongo/s/catalog/type_config_version.h"
+#include "mongo/s/catalog/type_lockpings.h"
+#include "mongo/s/catalog/type_locks.h"
+#include "mongo/s/catalog/type_shard.h"
+#include "mongo/s/catalog/type_tags.h"
+#include "mongo/s/client/shard.h"
+#include "mongo/s/config_server_test_fixture.h"
+
+namespace mongo {
+namespace {
+
+using std::string;
+using std::vector;
+using unittest::assertGet;
+
+/**
+ * Takes two arrays of BSON objects and asserts that they contain the same documents
+ */
+void assertBSONObjsSame(const std::vector<BSONObj>& expectedBSON,
+                        const std::vector<BSONObj>& foundBSON) {
+    ASSERT_EQUALS(expectedBSON.size(), foundBSON.size());
+
+    for (const auto& expectedObj : expectedBSON) {
+        bool wasFound = false;
+        for (const auto& foundObj : foundBSON) {
+            if (expectedObj.woCompare(foundObj) == 0) {
+                wasFound = true;
+                break;
+            }
+        }
+        ASSERT_TRUE(wasFound);
+    }
+}
+
+using ConfigInitializationTest = ConfigServerTestFixture;
+
+TEST_F(ConfigInitializationTest, UpgradeNotNeeded) {
+    VersionType version;
+    version.setClusterId(OID::gen());
+    version.setCurrentVersion(CURRENT_CONFIG_VERSION);
+    version.setMinCompatibleVersion(MIN_COMPATIBLE_CONFIG_VERSION);
+    ASSERT_OK(insertToConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), version.toBSON()));
+
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto versionDoc = assertGet(findOneOnConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+
+    VersionType foundVersion = assertGet(VersionType::fromBSON(versionDoc));
+
+    ASSERT_EQUALS(version.getClusterId(), foundVersion.getClusterId());
+    ASSERT_EQUALS(version.getCurrentVersion(), foundVersion.getCurrentVersion());
+    ASSERT_EQUALS(version.getMinCompatibleVersion(), foundVersion.getMinCompatibleVersion());
+}
+
+TEST_F(ConfigInitializationTest, InitIncompatibleVersion) {
+    VersionType version;
+    version.setClusterId(OID::gen());
+    version.setCurrentVersion(MIN_COMPATIBLE_CONFIG_VERSION - 1);
+    version.setMinCompatibleVersion(MIN_COMPATIBLE_CONFIG_VERSION - 2);
+    ASSERT_OK(insertToConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), version.toBSON()));
+
+    ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion,
+              catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto versionDoc = assertGet(findOneOnConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+
+    VersionType foundVersion = assertGet(VersionType::fromBSON(versionDoc));
+
+    ASSERT_EQUALS(version.getClusterId(), foundVersion.getClusterId());
+    ASSERT_EQUALS(version.getCurrentVersion(), foundVersion.getCurrentVersion());
+    ASSERT_EQUALS(version.getMinCompatibleVersion(), foundVersion.getMinCompatibleVersion());
+}
+
+TEST_F(ConfigInitializationTest, InitClusterMultipleVersionDocs) {
+    VersionType version;
+    version.setClusterId(OID::gen());
+    version.setCurrentVersion(MIN_COMPATIBLE_CONFIG_VERSION - 2);
+    version.setMinCompatibleVersion(MIN_COMPATIBLE_CONFIG_VERSION - 3);
+    ASSERT_OK(insertToConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), version.toBSON()));
+
+    ASSERT_OK(insertToConfigCollection(operationContext(),
+                                       NamespaceString(VersionType::ConfigNS),
+                                       BSON("_id"
+                                            << "a second document")));
+
+    ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion,
+              catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+}
+
+TEST_F(ConfigInitializationTest, InitInvalidConfigVersionDoc) {
+    BSONObj versionDoc(fromjson(R"({
+                    _id: 1,
+                    minCompatibleVersion: "should be numeric",
+                    currentVersion: 7,
+                    clusterId: ObjectId("55919cc6dbe86ce7ac056427")
+                })"));
+    ASSERT_OK(insertToConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), versionDoc));
+
+    ASSERT_EQ(ErrorCodes::UnsupportedFormat,
+              catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+}
+
+
+TEST_F(ConfigInitializationTest, InitNoVersionDocEmptyConfig) {
+    // Make sure there is no existing document
+    ASSERT_EQUALS(ErrorCodes::NoMatchingDocument,
+                  findOneOnConfigCollection(
+                      operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto versionDoc = assertGet(findOneOnConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+
+    VersionType foundVersion = assertGet(VersionType::fromBSON(versionDoc));
+
+    ASSERT_TRUE(foundVersion.getClusterId().isSet());
+    ASSERT_EQUALS(CURRENT_CONFIG_VERSION, foundVersion.getCurrentVersion());
+    ASSERT_EQUALS(MIN_COMPATIBLE_CONFIG_VERSION, foundVersion.getMinCompatibleVersion());
+}
+
+TEST_F(ConfigInitializationTest, InitVersionTooHigh) {
+    VersionType version;
+    version.setClusterId(OID::gen());
+    version.setCurrentVersion(10000);
+    version.setMinCompatibleVersion(10000);
+    ASSERT_OK(insertToConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), version.toBSON()));
+
+    ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion,
+              catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+}
+
+TEST_F(ConfigInitializationTest, OnlyRunsOnce) {
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto versionDoc = assertGet(findOneOnConfigCollection(
+        operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+
+    VersionType foundVersion = assertGet(VersionType::fromBSON(versionDoc));
+
+    ASSERT_TRUE(foundVersion.getClusterId().isSet());
+    ASSERT_EQUALS(CURRENT_CONFIG_VERSION, foundVersion.getCurrentVersion());
+    ASSERT_EQUALS(MIN_COMPATIBLE_CONFIG_VERSION, foundVersion.getMinCompatibleVersion());
+
+    // Now drop all databases and re-run initializeConfigDatabaseIfNeeded()
+    _dropAllDBs(operationContext());
+
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    // Even though there was no version document, initializeConfigDatabaseIfNeeded() returned
+    // without making one because it has already run once successfully so didn't bother to check.
+    ASSERT_EQUALS(ErrorCodes::NoMatchingDocument,
+                  findOneOnConfigCollection(
+                      operationContext(), NamespaceString(VersionType::ConfigNS), BSONObj()));
+}
+
+TEST_F(ConfigInitializationTest, BuildsNecessaryIndexes) {
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto expectedChunksIndexes = std::vector<BSONObj>{
+        BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                 << "_id_"
+                 << "ns"
+                 << "config.chunks"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("ns" << 1 << "min" << 1) << "name"
+                 << "ns_1_min_1"
+                 << "ns"
+                 << "config.chunks"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("ns" << 1 << "shard" << 1 << "min" << 1)
+                 << "name"
+                 << "ns_1_shard_1_min_1"
+                 << "ns"
+                 << "config.chunks"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("ns" << 1 << "lastmod" << 1) << "name"
+                 << "ns_1_lastmod_1"
+                 << "ns"
+                 << "config.chunks")};
+    auto expectedLockpingsIndexes =
+        std::vector<BSONObj>{BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                                      << "_id_"
+                                      << "ns"
+                                      << "config.lockpings"),
+                             BSON("v" << 1 << "key" << BSON("ping" << 1) << "name"
+                                      << "ping_1"
+                                      << "ns"
+                                      << "config.lockpings")};
+    auto expectedLocksIndexes = std::vector<BSONObj>{
+        BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                 << "_id_"
+                 << "ns"
+                 << "config.locks"),
+        BSON("v" << 1 << "key" << BSON("ts" << 1) << "name"
+                 << "ts_1"
+                 << "ns"
+                 << "config.locks"),
+        BSON("v" << 1 << "key" << BSON("state" << 1 << "process" << 1) << "name"
+                 << "state_1_process_1"
+                 << "ns"
+                 << "config.locks")};
+    auto expectedShardsIndexes = std::vector<BSONObj>{
+        BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                 << "_id_"
+                 << "ns"
+                 << "config.shards"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("host" << 1) << "name"
+                 << "host_1"
+                 << "ns"
+                 << "config.shards")};
+    auto expectedTagsIndexes = std::vector<BSONObj>{
+        BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                 << "_id_"
+                 << "ns"
+                 << "config.tags"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("ns" << 1 << "min" << 1) << "name"
+                 << "ns_1_min_1"
+                 << "ns"
+                 << "config.tags"),
+        BSON("v" << 1 << "key" << BSON("ns" << 1 << "tag" << 1) << "name"
+                 << "ns_1_tag_1"
+                 << "ns"
+                 << "config.tags")};
+
+    auto foundChunksIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(ChunkType::ConfigNS)));
+    assertBSONObjsSame(expectedChunksIndexes, foundChunksIndexes);
+
+    auto foundLockpingsIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(LockpingsType::ConfigNS)));
+    assertBSONObjsSame(expectedLockpingsIndexes, foundLockpingsIndexes);
+
+    auto foundLocksIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(LocksType::ConfigNS)));
+    assertBSONObjsSame(expectedLocksIndexes, foundLocksIndexes);
+
+    auto foundShardsIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(ShardType::ConfigNS)));
+    assertBSONObjsSame(expectedShardsIndexes, foundShardsIndexes);
+
+    auto foundTagsIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(TagsType::ConfigNS)));
+    assertBSONObjsSame(expectedTagsIndexes, foundTagsIndexes);
+}
+
+TEST_F(ConfigInitializationTest, CompatibleIndexAlreadyExists) {
+    getConfigShard()->createIndexOnConfig(
+        operationContext(), NamespaceString(ShardType::ConfigNS), BSON("host" << 1), true);
+
+    ASSERT_OK(catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+
+    auto expectedShardsIndexes = std::vector<BSONObj>{
+        BSON("v" << 1 << "key" << BSON("_id" << 1) << "name"
+                 << "_id_"
+                 << "ns"
+                 << "config.shards"),
+        BSON("v" << 1 << "unique" << true << "key" << BSON("host" << 1) << "name"
+                 << "host_1"
+                 << "ns"
+                 << "config.shards")};
+
+
+    auto foundShardsIndexes =
+        assertGet(getIndexes(operationContext(), NamespaceString(ShardType::ConfigNS)));
+    assertBSONObjsSame(expectedShardsIndexes, foundShardsIndexes);
+}
+
+TEST_F(ConfigInitializationTest, IncompatibleIndexAlreadyExists) {
+    // Make the index non-unique even though its supposed to be unique, make sure initialization
+    // fails
+    getConfigShard()->createIndexOnConfig(
+        operationContext(), NamespaceString(ShardType::ConfigNS), BSON("host" << 1), false);
+
+    ASSERT_EQUALS(ErrorCodes::IndexOptionsConflict,
+                  catalogManager()->initializeConfigDatabaseIfNeeded(operationContext()));
+}
+
+}  // unnamed namespace
+}  // namespace mongo
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.cpp b/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.cpp
index b7269cc4739..39e0a6bae52 100644
--- a/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.cpp
+++ b/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.cpp
@@ -43,14 +43,20 @@
 #include "mongo/client/remote_command_targeter.h"
 #include "mongo/client/replica_set_monitor.h"
 #include "mongo/db/concurrency/d_concurrency.h"
+#include "mongo/db/dbdirectclient.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/operation_context.h"
 #include "mongo/db/s/type_shard_identity.h"
 #include "mongo/executor/network_interface.h"
 #include "mongo/executor/task_executor.h"
 #include "mongo/rpc/get_status_from_command_result.h"
+#include "mongo/s/catalog/config_server_version.h"
 #include "mongo/s/catalog/sharding_catalog_client.h"
+#include "mongo/s/catalog/type_chunk.h"
+#include "mongo/s/catalog/type_config_version.h"
 #include "mongo/s/catalog/type_database.h"
+#include "mongo/s/catalog/type_lockpings.h"
+#include "mongo/s/catalog/type_locks.h"
 #include "mongo/s/catalog/type_shard.h"
 #include "mongo/s/catalog/type_tags.h"
 #include "mongo/s/client/shard.h"
@@ -719,4 +725,208 @@ void ShardingCatalogManagerImpl::appendConnectionStats(executor::ConnectionPoolS
     _executorForAddShard->appendConnectionStats(stats);
 }
 
+Status ShardingCatalogManagerImpl::initializeConfigDatabaseIfNeeded(OperationContext* txn) {
+    {
+        stdx::lock_guard<stdx::mutex> lk(_mutex);
+        if (_configInitialized) {
+            return Status::OK();
+        }
+    }
+
+    Status status = _initConfigVersion(txn);
+    if (!status.isOK()) {
+        return status;
+    }
+
+    status = _initConfigIndexes(txn);
+    if (!status.isOK()) {
+        return status;
+    }
+
+    stdx::lock_guard<stdx::mutex> lk(_mutex);
+    _configInitialized = true;
+
+    return Status::OK();
+}
+
+StatusWith<VersionType> ShardingCatalogManagerImpl::_getConfigVersion(OperationContext* txn) {
+    auto findStatus = Grid::get(txn)->shardRegistry()->getConfigShard()->exhaustiveFindOnConfig(
+        txn,
+        kConfigReadSelector,
+        // Use local read concern as we're likely to follow this up with a write.
+        repl::ReadConcernLevel::kLocalReadConcern,
+        NamespaceString(VersionType::ConfigNS),
+        BSONObj(),
+        BSONObj(),
+        boost::none /* no limit */);
+    if (!findStatus.isOK()) {
+        return findStatus.getStatus();
+    }
+
+    auto queryResults = findStatus.getValue().docs;
+
+    if (queryResults.size() > 1) {
+        return {ErrorCodes::IncompatibleShardingConfigVersion,
+                str::stream() << "should only have 1 document in " << VersionType::ConfigNS};
+    }
+
+    if (queryResults.empty()) {
+        VersionType versionInfo;
+        versionInfo.setMinCompatibleVersion(UpgradeHistory_EmptyVersion);
+        versionInfo.setCurrentVersion(UpgradeHistory_EmptyVersion);
+        return versionInfo;
+    }
+
+    BSONObj versionDoc = queryResults.front();
+    auto versionTypeResult = VersionType::fromBSON(versionDoc);
+    if (!versionTypeResult.isOK()) {
+        return Status(ErrorCodes::UnsupportedFormat,
+                      str::stream() << "invalid config version document: " << versionDoc
+                                    << versionTypeResult.getStatus().toString());
+    }
+
+    return versionTypeResult.getValue();
+}
+
+Status ShardingCatalogManagerImpl::_initConfigVersion(OperationContext* txn) {
+    auto versionStatus = _getConfigVersion(txn);
+    if (!versionStatus.isOK()) {
+        return versionStatus.getStatus();
+    }
+
+    auto versionInfo = versionStatus.getValue();
+    if (versionInfo.getMinCompatibleVersion() > CURRENT_CONFIG_VERSION) {
+        return {ErrorCodes::IncompatibleShardingConfigVersion,
+                str::stream() << "current version v" << CURRENT_CONFIG_VERSION
+                              << " is older than the cluster min compatible v"
+                              << versionInfo.getMinCompatibleVersion()};
+    }
+
+    if (versionInfo.getCurrentVersion() == UpgradeHistory_EmptyVersion) {
+        VersionType newVersion;
+        newVersion.setClusterId(OID::gen());
+        newVersion.setMinCompatibleVersion(MIN_COMPATIBLE_CONFIG_VERSION);
+        newVersion.setCurrentVersion(CURRENT_CONFIG_VERSION);
+
+        BSONObj versionObj(newVersion.toBSON());
+        auto insertStatus = _catalogClient->insertConfigDocument(
+            txn, VersionType::ConfigNS, versionObj, kNoWaitWriteConcern);
+
+        return insertStatus;
+    }
+
+    if (versionInfo.getCurrentVersion() == UpgradeHistory_UnreportedVersion) {
+        return {ErrorCodes::IncompatibleShardingConfigVersion,
+                "Assuming config data is old since the version document cannot be found in the "
+                "config server and it contains databases besides 'local' and 'admin'. "
+                "Please upgrade if this is the case. Otherwise, make sure that the config "
+                "server is clean."};
+    }
+
+    if (versionInfo.getCurrentVersion() < CURRENT_CONFIG_VERSION) {
+        return {ErrorCodes::IncompatibleShardingConfigVersion,
+                str::stream() << "need to upgrade current cluster version to v"
+                              << CURRENT_CONFIG_VERSION
+                              << "; currently at v"
+                              << versionInfo.getCurrentVersion()};
+    }
+
+    return Status::OK();
+}
+
+Status ShardingCatalogManagerImpl::_initConfigIndexes(OperationContext* txn) {
+    const bool unique = true;
+    auto configShard = Grid::get(txn)->shardRegistry()->getConfigShard();
+
+    Status result =
+        configShard->createIndexOnConfig(txn,
+                                         NamespaceString(ChunkType::ConfigNS),
+                                         BSON(ChunkType::ns() << 1 << ChunkType::min() << 1),
+                                         unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create ns_1_min_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(
+        txn,
+        NamespaceString(ChunkType::ConfigNS),
+        BSON(ChunkType::ns() << 1 << ChunkType::shard() << 1 << ChunkType::min() << 1),
+        unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create ns_1_shard_1_min_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(
+        txn,
+        NamespaceString(ChunkType::ConfigNS),
+        BSON(ChunkType::ns() << 1 << ChunkType::DEPRECATED_lastmod() << 1),
+        unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create ns_1_lastmod_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(
+        txn, NamespaceString(ShardType::ConfigNS), BSON(ShardType::host() << 1), unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create host_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(
+        txn, NamespaceString(LocksType::ConfigNS), BSON(LocksType::lockID() << 1), !unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create lock id index on config db"
+                                    << causedBy(result));
+    }
+
+    result =
+        configShard->createIndexOnConfig(txn,
+                                         NamespaceString(LocksType::ConfigNS),
+                                         BSON(LocksType::state() << 1 << LocksType::process() << 1),
+                                         !unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create state and process id index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(
+        txn, NamespaceString(LockpingsType::ConfigNS), BSON(LockpingsType::ping() << 1), !unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create lockping ping time index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(txn,
+                                              NamespaceString(TagsType::ConfigNS),
+                                              BSON(TagsType::ns() << 1 << TagsType::min() << 1),
+                                              unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create ns_1_min_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    result = configShard->createIndexOnConfig(txn,
+                                              NamespaceString(TagsType::ConfigNS),
+                                              BSON(TagsType::ns() << 1 << TagsType::tag() << 1),
+                                              !unique);
+    if (!result.isOK()) {
+        return Status(result.code(),
+                      str::stream() << "couldn't create ns_1_tag_1 index on config db"
+                                    << causedBy(result));
+    }
+
+    return Status::OK();
+}
+
 }  // namespace mongo
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.h b/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.h
index 3fb1f7c627b..bfacef70a57 100644
--- a/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.h
+++ b/src/mongo/s/catalog/replset/sharding_catalog_manager_impl.h
@@ -38,6 +38,7 @@ namespace mongo {
 
 class DatabaseType;
 class ShardingCatalogClient;
+class VersionType;
 
 namespace executor {
 class TaskExecutor;
@@ -75,6 +76,8 @@ public:
 
     void appendConnectionStats(executor::ConnectionPoolStats* stats) override;
 
+    Status initializeConfigDatabaseIfNeeded(OperationContext* txn) override;
+
 private:
     /**
      * Generates a unique name to be given to a newly added shard.
@@ -118,7 +121,21 @@ private:
                                                               const std::string& dbName,
                                                               const BSONObj& cmdObj);
 
+    /**
+     * Returns the current cluster schema/protocol version.
+     */
+    StatusWith<VersionType> _getConfigVersion(OperationContext* txn);
 
+    /**
+     * Performs the necessary checks for version compatibility and creates a new config.version
+     * document if the current cluster config is empty.
+     */
+    Status _initConfigVersion(OperationContext* txn);
+
+    /**
+     * Builds all the expected indexes on the config server.
+     */
+    Status _initConfigIndexes(OperationContext* txn);
     //
     // All member variables are labeled with one of the following codes indicating the
     // synchronization rules for accessing them.
@@ -145,6 +162,9 @@ private:
 
     // True if startup() has been called.
     bool _started = false;  // (M)
+
+    // True if initializeConfigDatabaseIfNeeded() has been called and returned successfully.
+    bool _configInitialized = false;  // (M)
 };
 
 }  // namespace mongo
diff --git a/src/mongo/s/catalog/replset/sharding_catalog_upgrade_test.cpp b/src/mongo/s/catalog/replset/sharding_catalog_upgrade_test.cpp
deleted file mode 100644
index 8dc55bd5086..00000000000
--- a/src/mongo/s/catalog/replset/sharding_catalog_upgrade_test.cpp
+++ /dev/null
@@ -1,605 +0,0 @@
-/**
- *    Copyright (C) 2015 MongoDB Inc.
- *
- *    This program is free software: you can redistribute it and/or  modify
- *    it under the terms of the GNU Affero General Public License, version 3,
- *    as published by the Free Software Foundation.
- *
- *    This program is distributed in the hope that it will be useful,
- *    but WITHOUT ANY WARRANTY; without even the implied warranty of
- *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *    GNU Affero General Public License for more details.
- *
- *    You should have received a copy of the GNU Affero General Public License
- *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- *    As a special exception, the copyright holders give permission to link the
- *    code of portions of this program with the OpenSSL library under certain
- *    conditions as described in each individual source file and distribute
- *    linked combinations including the program with the OpenSSL library. You
- *    must comply with the GNU Affero General Public License in all respects for
- *    all of the code used other than as permitted herein. If you modify file(s)
- *    with this exception, you may extend this exception to your version of the
- *    file(s), but you are not obligated to do so. If you do not wish to do so,
- *    delete this exception statement from your version. If you delete this
- *    exception statement from all source files in the program, then also delete
- *    it in the license file.
- */
-
-#include "mongo/platform/basic.h"
-
-#include <string>
-#include <vector>
-
-#include "mongo/bson/json.h"
-#include "mongo/client/remote_command_targeter_mock.h"
-#include "mongo/rpc/metadata/repl_set_metadata.h"
-#include "mongo/rpc/metadata/server_selection_metadata.h"
-#include "mongo/s/catalog/config_server_version.h"
-#include "mongo/s/catalog/replset/sharding_catalog_client_impl.h"
-#include "mongo/s/catalog/replset/sharding_catalog_test_fixture.h"
-#include "mongo/s/catalog/type_config_version.h"
-#include "mongo/s/write_ops/batched_command_response.h"
-#include "mongo/s/write_ops/batched_update_request.h"
-
-namespace mongo {
-namespace {
-
-using executor::RemoteCommandRequest;
-using executor::RemoteCommandResponse;
-using std::string;
-using std::vector;
-
-const BSONObj kReplSecondaryOkMetadata{[] {
-    BSONObjBuilder o;
-    o.appendElements(rpc::ServerSelectionMetadata(true, boost::none).toBSON());
-    o.append(rpc::kReplSetMetadataFieldName, 1);
-    return o.obj();
-}()};
-
-TEST_F(ShardingCatalogTestFixture, UpgradeNotNeeded) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(kReplSecondaryOkMetadata, request.metadata);
-
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        const auto& findCmd = request.cmdObj;
-        ASSERT_EQ("version", findCmd["find"].str());
-        checkReadConcern(findCmd, Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
-
-        BSONObj versionDoc(BSON("_id" << 1 << "minCompatibleVersion"
-                                      << MIN_COMPATIBLE_CONFIG_VERSION
-                                      << "currentVersion"
-                                      << CURRENT_CONFIG_VERSION
-                                      << "clusterId"
-                                      << OID::gen()));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitTargetError) {
-    configTargeter()->setFindHostReturnValue({ErrorCodes::InternalError, "Bad test network"});
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::InternalError, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitIncompatibleVersion) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) {
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 2,
-                currentVersion: 3,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitClusterMultiVersion) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::RemoteValidationError, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) {
-
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 2,
-                currentVersion: 3,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        BSONObj versionDoc2(fromjson(R"({
-                _id: 2,
-                minCompatibleVersion: 3,
-                currentVersion: 4,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc, versionDoc2};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitInvalidConfigVersionDoc) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::UnsupportedFormat, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) {
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: "should be numeric",
-                currentVersion: 7,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitNoVersionDocEmptyConfig) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
-
-        BatchedUpdateRequest actualBatchedUpdate;
-        std::string errmsg;
-        ASSERT_TRUE(actualBatchedUpdate.parseBSON(request.dbname, request.cmdObj, &errmsg));
-        ASSERT_EQUALS(VersionType::ConfigNS, actualBatchedUpdate.getNS().ns());
-
-        auto updates = actualBatchedUpdate.getUpdates();
-        ASSERT_EQUALS(1U, updates.size());
-        auto update = updates.front();
-
-        ASSERT_EQUALS(update->getQuery(), update->getUpdateExpr());
-        ASSERT_TRUE(update->getUpsert());
-        ASSERT_FALSE(update->getMulti());
-
-        auto versionDocRes = VersionType::fromBSON(update->getUpdateExpr());
-        ASSERT_OK(versionDocRes.getStatus());
-        const VersionType& versionDoc = versionDocRes.getValue();
-
-        ASSERT_EQ(MIN_COMPATIBLE_CONFIG_VERSION, versionDoc.getMinCompatibleVersion());
-        ASSERT_EQ(CURRENT_CONFIG_VERSION, versionDoc.getCurrentVersion());
-        ASSERT_TRUE(versionDoc.isClusterIdSet());
-        ASSERT_FALSE(versionDoc.isExcludingMongoVersionsSet());
-        ASSERT_FALSE(versionDoc.isUpgradeIdSet());
-        ASSERT_FALSE(versionDoc.isUpgradeStateSet());
-
-        BatchedCommandResponse response;
-        response.setOk(true);
-        response.setN(1);
-        response.setNModified(1);
-
-        return response.toBSON();
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitConfigWriteError) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::ExceededTimeLimit, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0,
-                writeErrors: [{
-                    index: 0,
-                    code: 50,
-                    errmsg: "exceeded time limit"
-                }]
-            })");
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionTooOld) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) {
-        BatchedCommandResponse response;
-        response.setOk(true);
-        response.setNModified(1);
-
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 2000000000,
-                currentVersion: 2000000000,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionDuplicateKeyNoOpAfterRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0,
-                writeErrors: [{
-                    index: 0,
-                    code: 11000,
-                    errmsg: "E11000 duplicate key error index: config.v.$_id_ dup key: { : 1.0 }"
-                }]
-            })");
-    });
-
-    // Retry starts here
-
-    onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(kReplSecondaryOkMetadata, request.metadata);
-
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        const auto& findCmd = request.cmdObj;
-        ASSERT_EQ("version", findCmd["find"].str());
-        checkReadConcern(findCmd, Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
-
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 6,
-                currentVersion: 7,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionDuplicateKeyNoConfigVersionAfterRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0,
-                writeErrors: [{
-                    index: 0,
-                    code: 11000,
-                    errmsg: "E11000 duplicate key error index: config.v.$_id_ dup key: { : 1.0 }"
-                }]
-            })");
-    });
-
-    // Retry starts here
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
-
-        BatchedUpdateRequest actualBatchedUpdate;
-        std::string errmsg;
-        ASSERT_TRUE(actualBatchedUpdate.parseBSON(request.dbname, request.cmdObj, &errmsg));
-        ASSERT_EQUALS(VersionType::ConfigNS, actualBatchedUpdate.getNS().ns());
-
-        auto updates = actualBatchedUpdate.getUpdates();
-        ASSERT_EQUALS(1U, updates.size());
-        auto update = updates.front();
-
-        ASSERT_EQUALS(update->getQuery(), update->getUpdateExpr());
-        ASSERT_TRUE(update->getUpsert());
-        ASSERT_FALSE(update->getMulti());
-
-        auto versionDocRes = VersionType::fromBSON(update->getUpdateExpr());
-        ASSERT_OK(versionDocRes.getStatus());
-        const VersionType& versionDoc = versionDocRes.getValue();
-
-        ASSERT_EQ(MIN_COMPATIBLE_CONFIG_VERSION, versionDoc.getMinCompatibleVersion());
-        ASSERT_EQ(CURRENT_CONFIG_VERSION, versionDoc.getCurrentVersion());
-        ASSERT_TRUE(versionDoc.isClusterIdSet());
-        ASSERT_FALSE(versionDoc.isExcludingMongoVersionsSet());
-        ASSERT_FALSE(versionDoc.isUpgradeIdSet());
-        ASSERT_FALSE(versionDoc.isUpgradeStateSet());
-
-        BatchedCommandResponse response;
-        response.setOk(true);
-        response.setN(1);
-        response.setNModified(1);
-
-        return response.toBSON();
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionDuplicateKeyTooNewAfterRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0,
-                writeErrors: [{
-                    index: 0,
-                    code: 11000,
-                    errmsg: "E11000 duplicate key error index: config.v.$_id_ dup key: { : 1.0 }"
-                }]
-            })");
-    });
-
-    // Retry starts here
-
-    onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(kReplSecondaryOkMetadata, request.metadata);
-
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        const auto& findCmd = request.cmdObj;
-        ASSERT_EQ("version", findCmd["find"].str());
-        checkReadConcern(findCmd, Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
-
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 2000000000,
-                currentVersion: 2000000000,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionDuplicateKeyMaxRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future = launchAsync([this] {
-        auto status = catalogClient()->initConfigVersion(operationContext());
-        ASSERT_EQ(ErrorCodes::IncompatibleShardingConfigVersion, status.code());
-        ASSERT_FALSE(status.reason().empty());
-    });
-
-    const int maxRetry = 3;
-    for (int x = 0; x < maxRetry; x++) {
-        onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-        onCommand([](const RemoteCommandRequest& request) {
-            ASSERT_EQ(HostAndPort("config:123"), request.target);
-            ASSERT_EQ("config", request.dbname);
-
-            ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-            return fromjson(R"({
-                    ok: 1,
-                    nModified: 0,
-                    n: 0,
-                    writeErrors: [{
-                        index: 0,
-                        code: 11000,
-                        errmsg: "E11000 duplicate key error index: config.v.$_id_ dup key: { : 1 }"
-                    }]
-                })");
-        });
-    }
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionUpsertNoMatchNoOpAfterRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0
-            })");
-    });
-
-    // Retry starts here
-
-    onFindCommand([this](const RemoteCommandRequest& request) {
-        ASSERT_EQUALS(kReplSecondaryOkMetadata, request.metadata);
-
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        const auto& findCmd = request.cmdObj;
-        ASSERT_EQ("version", findCmd["find"].str());
-        checkReadConcern(findCmd, Timestamp(0, 0), repl::OpTime::kUninitializedTerm);
-
-        BSONObj versionDoc(fromjson(R"({
-                _id: 1,
-                minCompatibleVersion: 6,
-                currentVersion: 7,
-                clusterId: ObjectId("55919cc6dbe86ce7ac056427")
-            })"));
-
-        return vector<BSONObj>{versionDoc};
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-TEST_F(ShardingCatalogTestFixture, InitVersionUpsertNoMatchNoConfigVersionAfterRetry) {
-    configTargeter()->setFindHostReturnValue(HostAndPort("config:123"));
-
-    auto future =
-        launchAsync([this] { ASSERT_OK(catalogClient()->initConfigVersion(operationContext())); });
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQ(string("update"), request.cmdObj.firstElementFieldName());
-
-        return fromjson(R"({
-                ok: 1,
-                nModified: 0,
-                n: 0
-            })");
-    });
-
-    // Retry starts here
-
-    onFindCommand([](const RemoteCommandRequest& request) { return vector<BSONObj>{}; });
-
-    onCommand([](const RemoteCommandRequest& request) {
-        ASSERT_EQ(HostAndPort("config:123"), request.target);
-        ASSERT_EQ("config", request.dbname);
-
-        ASSERT_EQUALS(BSON(rpc::kReplSetMetadataFieldName << 1), request.metadata);
-
-        BatchedUpdateRequest actualBatchedUpdate;
-        std::string errmsg;
-        ASSERT_TRUE(actualBatchedUpdate.parseBSON(request.dbname, request.cmdObj, &errmsg));
-        ASSERT_EQUALS(VersionType::ConfigNS, actualBatchedUpdate.getNS().ns());
-
-        auto updates = actualBatchedUpdate.getUpdates();
-        ASSERT_EQUALS(1U, updates.size());
-        auto update = updates.front();
-
-        ASSERT_EQUALS(update->getQuery(), update->getUpdateExpr());
-        ASSERT_TRUE(update->getUpsert());
-        ASSERT_FALSE(update->getMulti());
-
-        auto versionDocRes = VersionType::fromBSON(update->getUpdateExpr());
-        ASSERT_OK(versionDocRes.getStatus());
-        const VersionType& versionDoc = versionDocRes.getValue();
-
-        ASSERT_EQ(MIN_COMPATIBLE_CONFIG_VERSION, versionDoc.getMinCompatibleVersion());
-        ASSERT_EQ(CURRENT_CONFIG_VERSION, versionDoc.getCurrentVersion());
-        ASSERT_TRUE(versionDoc.isClusterIdSet());
-        ASSERT_FALSE(versionDoc.isExcludingMongoVersionsSet());
-        ASSERT_FALSE(versionDoc.isUpgradeIdSet());
-        ASSERT_FALSE(versionDoc.isUpgradeStateSet());
-
-        BatchedCommandResponse response;
-        response.setOk(true);
-        response.setN(1);
-        response.setNModified(1);
-
-        return response.toBSON();
-    });
-
-    future.timed_get(kFutureTimeout);
-}
-
-}  // unnamed namespace
-}  // namespace mongo
diff --git a/src/mongo/s/catalog/sharding_catalog_client.h b/src/mongo/s/catalog/sharding_catalog_client.h
index 69ad148860a..bbf59af157a 100644
--- a/src/mongo/s/catalog/sharding_catalog_client.h
+++ b/src/mongo/s/catalog/sharding_catalog_client.h
@@ -416,12 +416,6 @@ public:
                                          const WriteConcernOptions& writeConcern) = 0;
 
     /**
-     * Performs the necessary checks for version compatibility and creates a new version document
-     * if the current cluster config is empty.
-     */
-    virtual Status initConfigVersion(OperationContext* txn) = 0;
-
-    /**
      * Appends the information about the config and admin databases in the config server
      * with the format for listDatabase.
      */
diff --git a/src/mongo/s/catalog/sharding_catalog_client_mock.cpp b/src/mongo/s/catalog/sharding_catalog_client_mock.cpp
index 2481a5336e2..1ba10b51582 100644
--- a/src/mongo/s/catalog/sharding_catalog_client_mock.cpp
+++ b/src/mongo/s/catalog/sharding_catalog_client_mock.cpp
@@ -220,10 +220,6 @@ DistLockManager* ShardingCatalogClientMock::getDistLockManager() {
     return _mockDistLockMgr.get();
 }
 
-Status ShardingCatalogClientMock::initConfigVersion(OperationContext* txn) {
-    return {ErrorCodes::InternalError, "Method not implemented"};
-}
-
 Status ShardingCatalogClientMock::appendInfoForConfigServerDatabases(OperationContext* txn,
                                                                      BSONArrayBuilder* builder) {
     return Status::OK();
diff --git a/src/mongo/s/catalog/sharding_catalog_client_mock.h b/src/mongo/s/catalog/sharding_catalog_client_mock.h
index 60b09546631..125c6b36ca7 100644
--- a/src/mongo/s/catalog/sharding_catalog_client_mock.h
+++ b/src/mongo/s/catalog/sharding_catalog_client_mock.h
@@ -159,8 +159,6 @@ public:
                                                          StringData whyMessage,
                                                          Milliseconds waitFor) override;
 
-    Status initConfigVersion(OperationContext* txn) override;
-
     Status appendInfoForConfigServerDatabases(OperationContext* txn,
                                               BSONArrayBuilder* builder) override;
 
diff --git a/src/mongo/s/catalog/sharding_catalog_manager.h b/src/mongo/s/catalog/sharding_catalog_manager.h
index 637f8b3f955..c830e03a362 100644
--- a/src/mongo/s/catalog/sharding_catalog_manager.h
+++ b/src/mongo/s/catalog/sharding_catalog_manager.h
@@ -112,6 +112,12 @@ public:
      */
     virtual void appendConnectionStats(executor::ConnectionPoolStats* stats) = 0;
 
+    /**
+     * Initializes the collections that live in the config server.  Mostly this involves building
+     * necessary indexes and populating the config.version document.
+     */
+    virtual Status initializeConfigDatabaseIfNeeded(OperationContext* txn) = 0;
+
 protected:
     ShardingCatalogManager() = default;
 };
diff --git a/src/mongo/s/catalog/sharding_catalog_manager_mock.cpp b/src/mongo/s/catalog/sharding_catalog_manager_mock.cpp
index bb12440da97..7ba2b08926f 100644
--- a/src/mongo/s/catalog/sharding_catalog_manager_mock.cpp
+++ b/src/mongo/s/catalog/sharding_catalog_manager_mock.cpp
@@ -70,4 +70,8 @@ Status ShardingCatalogManagerMock::removeShardFromZone(OperationContext* txn,
 
 void ShardingCatalogManagerMock::appendConnectionStats(executor::ConnectionPoolStats* stats) {}
 
+Status ShardingCatalogManagerMock::initializeConfigDatabaseIfNeeded(OperationContext* txn) {
+    return {ErrorCodes::InternalError, "Method not implemented"};
+}
+
 }  // namespace mongo
diff --git a/src/mongo/s/catalog/sharding_catalog_manager_mock.h b/src/mongo/s/catalog/sharding_catalog_manager_mock.h
index 4be21103b8e..49057fc1bde 100644
--- a/src/mongo/s/catalog/sharding_catalog_manager_mock.h
+++ b/src/mongo/s/catalog/sharding_catalog_manager_mock.h
@@ -58,6 +58,8 @@ public:
                                const std::string& zoneName) override;
 
     void appendConnectionStats(executor::ConnectionPoolStats* stats) override;
+
+    Status initializeConfigDatabaseIfNeeded(OperationContext* txn) override;
 };
 
 }  // namespace mongo
diff --git a/src/mongo/s/client/shard.h b/src/mongo/s/client/shard.h
index d88d3fb67da..d2619f68b08 100644
--- a/src/mongo/s/client/shard.h
+++ b/src/mongo/s/client/shard.h
@@ -159,6 +159,17 @@ public:
                                                      const BSONObj& query,
                                                      const BSONObj& sort,
                                                      const boost::optional<long long> limit);
+    /**
+     * Builds an index on a config server collection.
+     * Creates the collection if it doesn't yet exist.  Does not error if the index already exists,
+     * so long as the options are the same.
+     * NOTE: Currently only supported for LocalShard.
+     */
+    virtual Status createIndexOnConfig(OperationContext* txn,
+                                       const NamespaceString& ns,
+                                       const BSONObj& keys,
+                                       bool unique) = 0;
+
 
 protected:
     Shard(const ShardId& id);
diff --git a/src/mongo/s/client/shard_local.cpp b/src/mongo/s/client/shard_local.cpp
index 86ba97eb148..dcf6db33205 100644
--- a/src/mongo/s/client/shard_local.cpp
+++ b/src/mongo/s/client/shard_local.cpp
@@ -178,5 +178,23 @@ StatusWith<Shard::QueryResponse> ShardLocal::_exhaustiveFindOnConfig(
     }
 }
 
+Status ShardLocal::createIndexOnConfig(OperationContext* txn,
+                                       const NamespaceString& ns,
+                                       const BSONObj& keys,
+                                       bool unique) {
+    invariant(ns.db() == "config" || ns.db() == "admin");
+
+    try {
+        DBDirectClient client(txn);
+        IndexSpec index;
+        index.addKeys(keys);
+        index.unique(unique);
+        client.createIndex(ns.toString(), index);
+    } catch (const DBException& e) {
+        return e.toStatus();
+    }
+
+    return Status::OK();
+}
 
 }  // namespace mongo
diff --git a/src/mongo/s/client/shard_local.h b/src/mongo/s/client/shard_local.h
index 764e814f25a..b39aba621d0 100644
--- a/src/mongo/s/client/shard_local.h
+++ b/src/mongo/s/client/shard_local.h
@@ -56,6 +56,11 @@ public:
 
     bool isRetriableError(ErrorCodes::Error code, RetryPolicy options) final;
 
+    Status createIndexOnConfig(OperationContext* txn,
+                               const NamespaceString& ns,
+                               const BSONObj& keys,
+                               bool unique) override;
+
 private:
     StatusWith<Shard::CommandResponse> _runCommand(OperationContext* txn,
                                                    const ReadPreferenceSetting& unused,
diff --git a/src/mongo/s/client/shard_local_test.cpp b/src/mongo/s/client/shard_local_test.cpp
index b334b7a95bb..b79fef28600 100644
--- a/src/mongo/s/client/shard_local_test.cpp
+++ b/src/mongo/s/client/shard_local_test.cpp
@@ -34,6 +34,7 @@
 #include "mongo/db/catalog/database_holder.h"
 #include "mongo/db/client.h"
 #include "mongo/db/db_raii.h"
+#include "mongo/db/query/cursor_response.h"
 #include "mongo/db/query/find_and_modify_request.h"
 #include "mongo/db/repl/replication_coordinator_global.h"
 #include "mongo/db/repl/replication_coordinator_mock.h"
@@ -67,6 +68,11 @@ protected:
                                                   BSONObj sort,
                                                   boost::optional<long long> limit);
 
+    /**
+     * Returns the index definitions that exist for the given collection.
+     */
+    StatusWith<std::vector<BSONObj>> getIndexes(NamespaceString nss);
+
 private:
     void setUp() override;
     void tearDown() override;
@@ -103,6 +109,26 @@ StatusWith<Shard::CommandResponse> ShardLocalTest::runFindAndModifyRunCommand(Na
                                    Shard::RetryPolicy::kNoRetry);
 }
 
+StatusWith<std::vector<BSONObj>> ShardLocalTest::getIndexes(NamespaceString nss) {
+    auto response = _shardLocal->runCommand(_txn.get(),
+                                            ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+                                            nss.db().toString(),
+                                            BSON("listIndexes" << nss.coll().toString()),
+                                            Shard::RetryPolicy::kIdempotent);
+    if (!response.isOK()) {
+        return response.getStatus();
+    }
+    if (!response.getValue().commandStatus.isOK()) {
+        return response.getValue().commandStatus;
+    }
+
+    auto cursorResponse = CursorResponse::parseFromBSON(response.getValue().response);
+    if (!cursorResponse.isOK()) {
+        return cursorResponse.getStatus();
+    }
+    return cursorResponse.getValue().getBatch();
+}
+
 /**
  * Takes a FindAndModify command's BSON response and parses it for the returned "value" field.
  */
@@ -210,5 +236,32 @@ TEST_F(ShardLocalTest, FindNoMatchingDocumentsEmpty) {
     ASSERT_EQUALS(size, docs.size());
 }
 
+TEST_F(ShardLocalTest, CreateIndex) {
+    NamespaceString nss("config.foo");
+
+    ASSERT_EQUALS(ErrorCodes::NamespaceNotFound, getIndexes(nss).getStatus());
+
+    Status status =
+        _shardLocal->createIndexOnConfig(_txn.get(), nss, BSON("a" << 1 << "b" << 1), true);
+    // Creating the index should implicitly create the collection
+    ASSERT_OK(status);
+
+    auto indexes = unittest::assertGet(getIndexes(nss));
+    // There should be the index we just added as well as the _id index
+    ASSERT_EQ(2U, indexes.size());
+
+    // Making an identical index should be a no-op.
+    status = _shardLocal->createIndexOnConfig(_txn.get(), nss, BSON("a" << 1 << "b" << 1), true);
+    ASSERT_OK(status);
+    indexes = unittest::assertGet(getIndexes(nss));
+    ASSERT_EQ(2U, indexes.size());
+
+    // Trying to make the same index as non-unique should fail.
+    status = _shardLocal->createIndexOnConfig(_txn.get(), nss, BSON("a" << 1 << "b" << 1), false);
+    ASSERT_EQUALS(ErrorCodes::IndexOptionsConflict, status);
+    indexes = unittest::assertGet(getIndexes(nss));
+    ASSERT_EQ(2U, indexes.size());
+}
+
 }  // namespace
 }  // namespace mongo
diff --git a/src/mongo/s/client/shard_remote.cpp b/src/mongo/s/client/shard_remote.cpp
index d0f23563803..c28067b3261 100644
--- a/src/mongo/s/client/shard_remote.cpp
+++ b/src/mongo/s/client/shard_remote.cpp
@@ -369,4 +369,11 @@ StatusWith<Shard::QueryResponse> ShardRemote::_exhaustiveFindOnConfig(
     return response;
 }
 
+Status ShardRemote::createIndexOnConfig(OperationContext* txn,
+                                        const NamespaceString& ns,
+                                        const BSONObj& keys,
+                                        bool unique) {
+    MONGO_UNREACHABLE;
+}
+
 }  // namespace mongo
diff --git a/src/mongo/s/client/shard_remote.h b/src/mongo/s/client/shard_remote.h
index 5f19a2c4301..339f0ae1b31 100644
--- a/src/mongo/s/client/shard_remote.h
+++ b/src/mongo/s/client/shard_remote.h
@@ -70,6 +70,11 @@ public:
 
     bool isRetriableError(ErrorCodes::Error code, RetryPolicy options) final;
 
+    Status createIndexOnConfig(OperationContext* txn,
+                               const NamespaceString& ns,
+                               const BSONObj& keys,
+                               bool unique) override;
+
 private:
     /**
      * Returns the metadata that should be used when running commands against this shard with
diff --git a/src/mongo/s/config_server_test_fixture.cpp b/src/mongo/s/config_server_test_fixture.cpp
index 76c73854ddf..c04d0df2a06 100644
--- a/src/mongo/s/config_server_test_fixture.cpp
+++ b/src/mongo/s/config_server_test_fixture.cpp
@@ -39,6 +39,7 @@
 #include "mongo/db/client.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/namespace_string.h"
+#include "mongo/db/query/cursor_response.h"
 #include "mongo/db/query/query_request.h"
 #include "mongo/db/repl/read_concern_args.h"
 #include "mongo/db/repl/repl_settings.h"
@@ -299,9 +300,33 @@ Status ConfigServerTestFixture::insertToConfigCollection(OperationContext* txn,
     auto config = getConfigShard();
     invariant(config);
 
-    auto insertStatus = config->runCommand(
+    auto insertResponse = config->runCommand(
         txn, kReadPref, ns.db().toString(), request.toBSON(), Shard::RetryPolicy::kNoRetry);
-    return insertStatus.getStatus();
+
+    BatchedCommandResponse batchResponse;
+    auto status = Shard::CommandResponse::processBatchWriteResponse(insertResponse, &batchResponse);
+    return status;
+}
+
+StatusWith<BSONObj> ConfigServerTestFixture::findOneOnConfigCollection(OperationContext* txn,
+                                                                       const NamespaceString& ns,
+                                                                       const BSONObj& filter) {
+    auto config = getConfigShard();
+    invariant(config);
+
+    auto findStatus = config->exhaustiveFindOnConfig(
+        txn, kReadPref, repl::ReadConcernLevel::kMajorityReadConcern, ns, filter, BSONObj(), 1);
+    if (!findStatus.isOK()) {
+        return findStatus.getStatus();
+    }
+
+    auto findResult = findStatus.getValue();
+    if (findResult.docs.empty()) {
+        return Status(ErrorCodes::NoMatchingDocument, "No document found");
+    }
+
+    invariant(findResult.docs.size() == 1);
+    return findResult.docs.front().getOwned();
 }
 
 Status ConfigServerTestFixture::setupShards(const std::vector<ShardType>& shards) {
@@ -318,29 +343,41 @@ Status ConfigServerTestFixture::setupShards(const std::vector<ShardType>& shards
 
 StatusWith<ShardType> ConfigServerTestFixture::getShardDoc(OperationContext* txn,
                                                            const std::string& shardId) {
-    auto config = getConfigShard();
-    invariant(config);
-
-    NamespaceString ns(ShardType::ConfigNS);
-    auto findStatus = config->exhaustiveFindOnConfig(txn,
-                                                     kReadPref,
-                                                     repl::ReadConcernLevel::kMajorityReadConcern,
-                                                     ns,
-                                                     BSON(ShardType::name(shardId)),
-                                                     BSONObj(),
-                                                     boost::none);
-    if (!findStatus.isOK()) {
-        return findStatus.getStatus();
+    auto doc = findOneOnConfigCollection(
+        txn, NamespaceString(ShardType::ConfigNS), BSON(ShardType::name(shardId)));
+    if (!doc.isOK()) {
+        if (doc.getStatus() == ErrorCodes::NoMatchingDocument) {
+            return {ErrorCodes::ShardNotFound,
+                    str::stream() << "shard " << shardId << " does not exist"};
+        }
+        return doc.getStatus();
     }
 
-    auto findResult = findStatus.getValue();
-    if (findResult.docs.empty()) {
-        return {ErrorCodes::ShardNotFound,
-                str::stream() << "shard " << shardId << " does not exist"};
+    return ShardType::fromBSON(doc.getValue());
+}
+
+StatusWith<std::vector<BSONObj>> ConfigServerTestFixture::getIndexes(OperationContext* txn,
+                                                                     const NamespaceString& ns) {
+    auto configShard = getConfigShard();
+
+    auto response = configShard->runCommand(txn,
+                                            ReadPreferenceSetting{ReadPreference::PrimaryOnly},
+                                            ns.db().toString(),
+                                            BSON("listIndexes" << ns.coll().toString()),
+                                            Shard::RetryPolicy::kIdempotent);
+    if (!response.isOK()) {
+        return response.getStatus();
+    }
+    if (!response.getValue().commandStatus.isOK()) {
+        return response.getValue().commandStatus;
     }
 
-    invariant(findResult.docs.size() == 1);
-    return ShardType::fromBSON(findResult.docs.front());
+    auto cursorResponse = CursorResponse::parseFromBSON(response.getValue().response);
+    if (!cursorResponse.isOK()) {
+        return cursorResponse.getStatus();
+    }
+    return cursorResponse.getValue().getBatch();
 }
 
+
 }  // namespace mongo
diff --git a/src/mongo/s/config_server_test_fixture.h b/src/mongo/s/config_server_test_fixture.h
index 9ad3c2f0de2..7deabf1b323 100644
--- a/src/mongo/s/config_server_test_fixture.h
+++ b/src/mongo/s/config_server_test_fixture.h
@@ -112,6 +112,13 @@ public:
                                     const BSONObj& doc);
 
     /**
+     * Reads a single document from a collection living on the config server.
+     */
+    StatusWith<BSONObj> findOneOnConfigCollection(OperationContext* txn,
+                                                  const NamespaceString& ns,
+                                                  const BSONObj& filter);
+
+    /**
      * Blocking methods, which receive one message from the network and respond using the
      * responses returned from the input function. This is a syntactic sugar for simple,
      * single request + response or find tests.
@@ -135,6 +142,11 @@ public:
      */
     StatusWith<ShardType> getShardDoc(OperationContext* txn, const std::string& shardId);
 
+    /**
+     * Returns the indexes definitions defined on a given collection.
+     */
+    StatusWith<std::vector<BSONObj>> getIndexes(OperationContext* txn, const NamespaceString& ns);
+
     void setUp() override;
 
     void tearDown() override;
diff --git a/src/mongo/s/server.cpp b/src/mongo/s/server.cpp
index f0dee91919e..af01e1d2c0e 100644
--- a/src/mongo/s/server.cpp
+++ b/src/mongo/s/server.cpp
@@ -66,17 +66,11 @@
 #include "mongo/s/balancer/balancer_configuration.h"
 #include "mongo/s/catalog/sharding_catalog_client.h"
 #include "mongo/s/catalog/sharding_catalog_manager.h"
-#include "mongo/s/catalog/type_chunk.h"
-#include "mongo/s/catalog/type_lockpings.h"
-#include "mongo/s/catalog/type_locks.h"
-#include "mongo/s/catalog/type_shard.h"
-#include "mongo/s/catalog/type_tags.h"
 #include "mongo/s/client/shard_connection.h"
 #include "mongo/s/client/shard_factory.h"
 #include "mongo/s/client/shard_registry.h"
 #include "mongo/s/client/shard_remote.h"
 #include "mongo/s/client/sharding_connection_hook_for_mongos.h"
-#include "mongo/s/cluster_write.h"
 #include "mongo/s/commands/request.h"
 #include "mongo/s/config.h"
 #include "mongo/s/grid.h"
@@ -222,72 +216,6 @@ public:
 
 using namespace mongo;
 
-static void reloadSettings(OperationContext* txn) {
-    Grid::get(txn)->getBalancerConfiguration()->refreshAndCheck(txn);
-
-    // Create the config data indexes
-    const bool unique = true;
-
-    Status result = clusterCreateIndex(
-        txn, ChunkType::ConfigNS, BSON(ChunkType::ns() << 1 << ChunkType::min() << 1), unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create ns_1_min_1 index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(
-        txn,
-        ChunkType::ConfigNS,
-        BSON(ChunkType::ns() << 1 << ChunkType::shard() << 1 << ChunkType::min() << 1),
-        unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create ns_1_shard_1_min_1 index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(txn,
-                                ChunkType::ConfigNS,
-                                BSON(ChunkType::ns() << 1 << ChunkType::DEPRECATED_lastmod() << 1),
-                                unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create ns_1_lastmod_1 index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(txn, ShardType::ConfigNS, BSON(ShardType::host() << 1), unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create host_1 index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(txn, LocksType::ConfigNS, BSON(LocksType::lockID() << 1), !unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create lock id index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(txn,
-                                LocksType::ConfigNS,
-                                BSON(LocksType::state() << 1 << LocksType::process() << 1),
-                                !unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create state and process id index on config db" << causedBy(result);
-    }
-
-    result =
-        clusterCreateIndex(txn, LockpingsType::ConfigNS, BSON(LockpingsType::ping() << 1), !unique);
-    if (!result.isOK()) {
-        warning() << "couldn't create lockping ping time index on config db" << causedBy(result);
-    }
-
-    result = clusterCreateIndex(
-        txn, TagsType::ConfigNS, BSON(TagsType::ns() << 1 << TagsType::min() << 1), unique);
-    if (!result.isOK()) {
-        warning() << "could not create index ns_1_min_1: " << causedBy(result);
-    }
-
-    result = clusterCreateIndex(
-        txn, TagsType::ConfigNS, BSON(TagsType::ns() << 1 << TagsType::tag() << 1), !unique);
-    if (!result.isOK()) {
-        warning() << "could not create index ns_1_tag_1: " << causedBy(result);
-    }
-}
-
 static Status initializeSharding(OperationContext* txn) {
     auto targeterFactory = stdx::make_unique<RemoteCommandTargeterFactoryImpl>();
     auto targeterFactoryPtr = targeterFactory.get();
@@ -329,12 +257,6 @@ static Status initializeSharding(OperationContext* txn) {
         return status;
     }
 
-    auto catalogClient = grid.catalogClient(txn);
-    status = catalogClient->initConfigVersion(txn);
-    if (!status.isOK()) {
-        return status;
-    }
-
     return Status::OK();
 }
 
@@ -385,7 +307,7 @@ static ExitCode runMongosServer() {
             return EXIT_SHARDING_ERROR;
         }
 
-        reloadSettings(opCtx.get());
+        Grid::get(opCtx.get())->getBalancerConfiguration()->refreshAndCheck(opCtx.get());
     }
 
 #if !defined(_WIN32)