Revert "SERVER-28433 Implement KeysCollectionCacheReaderAndUpdater"

This reverts commit 5fa258635ab142b502ebf055f15b7613d20f8f30.

8 files changed, 2 insertions, 621 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 6df38c3e2f8..66049a93d88 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -1036,12 +1036,10 @@ env.Library(
     target='keys_collection_manager',
     source=[
         'keys_collection_cache_reader.cpp',
-        'keys_collection_cache_reader_and_updater.cpp',
     ],
     LIBDEPS=[
         'keys_collection_document',
         'logical_time',
-        '$BUILD_DIR/mongo/s/coreshard',
     ],
 )
 
@@ -1051,6 +1049,7 @@ env.Library(
         'logical_clock.cpp',
     ],
     LIBDEPS=[
+        'keys_collection_manager',
         'server_parameters',
         'service_context',
         'signed_logical_time',
@@ -1137,17 +1136,6 @@ env.CppUnitTest(
     ],
 )
 
-env.CppUnitTest(
-    target='keys_collection_cache_reader_and_updater_test',
-    source=[
-        'keys_collection_cache_reader_and_updater_test.cpp',
-    ],
-    LIBDEPS=[
-        'keys_collection_manager',
-        '$BUILD_DIR/mongo/s/config_server_test_fixture',
-    ],
-)
-
 env.Library(
     target= 'op_observer_noop',
     source= [
diff --git a/src/mongo/db/keys_collection_cache_reader_and_updater.cpp b/src/mongo/db/keys_collection_cache_reader_and_updater.cpp
deleted file mode 100644
index 7c959c5f6c0..00000000000
--- a/src/mongo/db/keys_collection_cache_reader_and_updater.cpp
+++ /dev/null
@@ -1,147 +0,0 @@
-/**
- *    Copyright (C) 2017 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 "mongo/db/keys_collection_cache_reader_and_updater.h"
-
-#include "mongo/client/read_preference.h"
-#include "mongo/db/logical_clock.h"
-#include "mongo/db/operation_context.h"
-#include "mongo/s/catalog/sharding_catalog_client.h"
-#include "mongo/s/client/shard_registry.h"
-#include "mongo/s/grid.h"
-
-namespace mongo {
-
-namespace {
-
-/**
- * Inserts a new key to the keys collection.
- *
- * Note: this relies on the fact that ShardRegistry returns a ShardLocal for config in config
- * servers. In other words, it is relying on the fact that this will always execute the write
- * locally and never remotely even if this node is no longer primary.
- */
-Status insertNewKey(OperationContext* opCtx,
-                    long long keyId,
-                    const std::string& purpose,
-                    const LogicalTime& expiresAt) {
-    KeysCollectionDocument newKey(keyId, purpose, TimeProofService::generateRandomKey(), expiresAt);
-    return Grid::get(opCtx)->catalogClient(opCtx)->insertConfigDocument(
-        opCtx,
-        KeysCollectionDocument::ConfigNS,
-        newKey.toBSON(),
-        ShardingCatalogClient::kMajorityWriteConcern);
-}
-
-/**
- * Returns a new LogicalTime with the seconds argument added to it.
- */
-LogicalTime addSeconds(const LogicalTime& logicalTime, const Seconds& seconds) {
-    return LogicalTime(Timestamp(logicalTime.asTimestamp().getSecs() + seconds.count(), 0));
-}
-
-}  // unnamed namespace
-
-KeysCollectionCacheReaderAndUpdater::KeysCollectionCacheReaderAndUpdater(
-    std::string purpose, Seconds keyValidForInterval)
-    : KeysCollectionCacheReader(purpose),
-      _purpose(std::move(purpose)),
-      _keyValidForInterval(keyValidForInterval) {}
-
-StatusWith<KeysCollectionDocument> KeysCollectionCacheReaderAndUpdater::refresh(
-    OperationContext* opCtx) {
-
-    auto currentTime = LogicalClock::get(opCtx)->getClusterTime().getTime();
-    auto keyStatus = Grid::get(opCtx)->catalogClient(opCtx)->getNewKeys(
-        opCtx, _purpose, currentTime, repl::ReadConcernLevel::kLocalReadConcern);
-
-    if (!keyStatus.isOK()) {
-        return keyStatus.getStatus();
-    }
-
-    const auto& newKeys = keyStatus.getValue();
-    auto keyIter = newKeys.cbegin();
-
-    LogicalTime currentKeyExpiresAt;
-
-    long long keyId = currentTime.asTimestamp().asLL();
-
-    if (keyIter == newKeys.cend()) {
-        currentKeyExpiresAt = addSeconds(currentTime, _keyValidForInterval);
-        auto status = insertNewKey(opCtx, keyId, _purpose, currentKeyExpiresAt);
-
-        if (!status.isOK()) {
-            return status;
-        }
-
-        keyId++;
-    } else if (keyIter->getExpiresAt() < currentTime) {
-        currentKeyExpiresAt = addSeconds(currentTime, _keyValidForInterval);
-        auto status = insertNewKey(opCtx, keyId, _purpose, currentKeyExpiresAt);
-
-        if (!status.isOK()) {
-            return status;
-        }
-
-        keyId++;
-        ++keyIter;
-    } else {
-        currentKeyExpiresAt = keyIter->getExpiresAt();
-        ++keyIter;
-    }
-
-    // Create a new key in advance if we don't have a key on standby after the current one
-    // expires.
-    // Note: Convert this block into a loop if more reserved keys are desired.
-    if (keyIter == newKeys.cend()) {
-        auto reserveKeyExpiresAt = addSeconds(currentKeyExpiresAt, _keyValidForInterval);
-        auto status = insertNewKey(opCtx, keyId, _purpose, reserveKeyExpiresAt);
-
-        if (!status.isOK()) {
-            return status;
-        }
-    } else if (keyIter->getExpiresAt() < currentTime) {
-        currentKeyExpiresAt = addSeconds(currentKeyExpiresAt, _keyValidForInterval);
-        auto status = insertNewKey(opCtx, keyId, _purpose, currentKeyExpiresAt);
-
-        if (!status.isOK()) {
-            return status;
-        }
-    }
-
-    return KeysCollectionCacheReader::refresh(opCtx);
-}
-
-StatusWith<KeysCollectionDocument> KeysCollectionCacheReaderAndUpdater::getKey(
-    const LogicalTime& forThisTime) {
-    return KeysCollectionCacheReader::getKey(forThisTime);
-}
-
-}  // namespace mongo
diff --git a/src/mongo/db/keys_collection_cache_reader_and_updater.h b/src/mongo/db/keys_collection_cache_reader_and_updater.h
deleted file mode 100644
index e538a126bd3..00000000000
--- a/src/mongo/db/keys_collection_cache_reader_and_updater.h
+++ /dev/null
@@ -1,64 +0,0 @@
-/**
- *    Copyright (C) 2017 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.
- */
-
-#pragma once
-
-#include <string>
-
-#include "mongo/db/keys_collection_cache_reader.h"
-#include "mongo/util/duration.h"
-
-namespace mongo {
-
-/**
- * Keeps a local cache of the keys with the ability to refresh. The refresh method also makes sure
- * that there will be valid keys available to sign the current logical time and there will be
- * another key ready after the current key expires.
- *
- * Assumptions and limitations:
- * - assumes that user does not manually update the keys collection.
- * - assumes that current process is the config primary.
- */
-class KeysCollectionCacheReaderAndUpdater : public KeysCollectionCacheReader {
-public:
-    KeysCollectionCacheReaderAndUpdater(std::string purpose, Seconds keyValidForInterval);
-    ~KeysCollectionCacheReaderAndUpdater() = default;
-
-    /**
-     * Check if there are new documents expiresAt > latestKeyDoc.expiresAt.
-     */
-    StatusWith<KeysCollectionDocument> refresh(OperationContext* opCtx) override;
-
-    StatusWith<KeysCollectionDocument> getKey(const LogicalTime& forThisTime) override;
-
-private:
-    const std::string _purpose;
-    const Seconds _keyValidForInterval;
-};
-
-}  // namespace mongo
diff --git a/src/mongo/db/keys_collection_cache_reader_and_updater_test.cpp b/src/mongo/db/keys_collection_cache_reader_and_updater_test.cpp
deleted file mode 100644
index fdb8e150f07..00000000000
--- a/src/mongo/db/keys_collection_cache_reader_and_updater_test.cpp
+++ /dev/null
@@ -1,366 +0,0 @@
-/**
- *    Copyright (C) 2017 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 <set>
-#include <string>
-
-#include "mongo/db/jsobj.h"
-#include "mongo/db/keys_collection_cache_reader_and_updater.h"
-#include "mongo/db/keys_collection_document.h"
-#include "mongo/db/logical_clock.h"
-#include "mongo/db/namespace_string.h"
-#include "mongo/db/operation_context.h"
-#include "mongo/s/config_server_test_fixture.h"
-#include "mongo/stdx/memory.h"
-#include "mongo/unittest/unittest.h"
-#include "mongo/util/clock_source_mock.h"
-
-namespace mongo {
-
-class CacheUpdaterTest : public ConfigServerTestFixture {
-protected:
-    void setUp() override {
-        ConfigServerTestFixture::setUp();
-
-        auto clockSource = stdx::make_unique<ClockSourceMock>();
-        operationContext()->getServiceContext()->setFastClockSource(std::move(clockSource));
-    }
-};
-
-TEST_F(CacheUpdaterTest, ShouldCreate2KeysFromEmpty) {
-    KeysCollectionCacheReaderAndUpdater updater("dummy", Seconds(5));
-
-    const LogicalTime currentTime(LogicalTime(Timestamp(100, 2)));
-    LogicalClock::get(operationContext())->initClusterTimeFromTrustedSource(currentTime);
-
-    auto keyStatus = updater.refresh(operationContext());
-    // TODO: Inspect keyStatus once SERVER-28435 is implemented
-
-    auto allKeys = getKeys(operationContext());
-
-    ASSERT_EQ(2u, allKeys.size());
-
-    const auto& key1 = allKeys.front();
-    ASSERT_EQ(currentTime.asTimestamp().asLL(), key1.getKeyId());
-    ASSERT_EQ("dummy", key1.getPurpose());
-    ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-
-    const auto& key2 = allKeys.back();
-    ASSERT_EQ(currentTime.asTimestamp().asLL() + 1, key2.getKeyId());
-    ASSERT_EQ("dummy", key2.getPurpose());
-    ASSERT_EQ(Timestamp(110, 0), key2.getExpiresAt().asTimestamp());
-
-    ASSERT_NE(key1.getKey(), key2.getKey());
-}
-
-TEST_F(CacheUpdaterTest, ShouldCreateAnotherKeyIfOnlyOneKeyExists) {
-    KeysCollectionCacheReaderAndUpdater updater("dummy", Seconds(5));
-
-    LogicalClock::get(operationContext())
-        ->initClusterTimeFromTrustedSource(LogicalTime(Timestamp(100, 2)));
-
-    KeysCollectionDocument origKey1(
-        1, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(105, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey1.toBSON()));
-
-    {
-        auto allKeys = getKeys(operationContext());
-
-        ASSERT_EQ(1u, allKeys.size());
-
-        const auto& key1 = allKeys.front();
-        ASSERT_EQ(1, key1.getKeyId());
-        ASSERT_EQ("dummy", key1.getPurpose());
-        ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-    }
-
-    auto currentTime = LogicalClock::get(operationContext())->getClusterTime().getTime();
-    auto keyStatus = updater.refresh(operationContext());
-    // TODO: Inspect keyStatus once SERVER-28435 is implemented
-
-    {
-        auto allKeys = getKeys(operationContext());
-
-        ASSERT_EQ(2u, allKeys.size());
-
-        const auto& key1 = allKeys.front();
-        ASSERT_EQ(1, key1.getKeyId());
-        ASSERT_EQ("dummy", key1.getPurpose());
-        ASSERT_EQ(origKey1.getKey(), key1.getKey());
-        ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-
-        const auto& key2 = allKeys.back();
-        ASSERT_EQ(currentTime.asTimestamp().asLL(), key2.getKeyId());
-        ASSERT_EQ("dummy", key2.getPurpose());
-        ASSERT_EQ(Timestamp(110, 0), key2.getExpiresAt().asTimestamp());
-
-        ASSERT_NE(key1.getKey(), key2.getKey());
-    }
-}
-
-TEST_F(CacheUpdaterTest, ShouldCreateAnotherKeyIfNoValidKeyAfterCurrent) {
-    KeysCollectionCacheReaderAndUpdater updater("dummy", Seconds(5));
-
-    LogicalClock::get(operationContext())
-        ->initClusterTimeFromTrustedSource(LogicalTime(Timestamp(108, 2)));
-
-    KeysCollectionDocument origKey1(
-        1, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(105, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey1.toBSON()));
-
-    KeysCollectionDocument origKey2(
-        2, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(110, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey2.toBSON()));
-
-    {
-        auto allKeys = getKeys(operationContext());
-
-        ASSERT_EQ(2u, allKeys.size());
-
-        const auto& key1 = allKeys.front();
-        ASSERT_EQ(1, key1.getKeyId());
-        ASSERT_EQ("dummy", key1.getPurpose());
-        ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-
-        const auto& key2 = allKeys.back();
-        ASSERT_EQ(2, key2.getKeyId());
-        ASSERT_EQ("dummy", key2.getPurpose());
-        ASSERT_EQ(Timestamp(110, 0), key2.getExpiresAt().asTimestamp());
-    }
-
-    auto currentTime = LogicalClock::get(operationContext())->getClusterTime().getTime();
-    auto keyStatus = updater.refresh(operationContext());
-    // TODO: Inspect keyStatus once SERVER-28435 is implemented
-
-    auto allKeys = getKeys(operationContext());
-
-    ASSERT_EQ(3u, allKeys.size());
-
-    auto citer = allKeys.cbegin();
-
-    std::set<std::string> seenKeys;
-
-    {
-        const auto& key = *citer;
-        ASSERT_EQ(1, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey1.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(105, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(2, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey2.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(110, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(currentTime.asTimestamp().asLL(), key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(Timestamp(115, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-}
-
-TEST_F(CacheUpdaterTest, ShouldCreate2KeysIfAllKeysAreExpired) {
-    KeysCollectionCacheReaderAndUpdater updater("dummy", Seconds(5));
-
-    LogicalClock::get(operationContext())
-        ->initClusterTimeFromTrustedSource(LogicalTime(Timestamp(120, 2)));
-
-    KeysCollectionDocument origKey1(
-        1, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(105, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey1.toBSON()));
-
-    KeysCollectionDocument origKey2(
-        2, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(110, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey2.toBSON()));
-
-    {
-        auto allKeys = getKeys(operationContext());
-
-        ASSERT_EQ(2u, allKeys.size());
-
-        const auto& key1 = allKeys.front();
-        ASSERT_EQ(1, key1.getKeyId());
-        ASSERT_EQ("dummy", key1.getPurpose());
-        ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-
-        const auto& key2 = allKeys.back();
-        ASSERT_EQ(2, key2.getKeyId());
-        ASSERT_EQ("dummy", key2.getPurpose());
-        ASSERT_EQ(Timestamp(110, 0), key2.getExpiresAt().asTimestamp());
-    }
-
-    auto currentTime = LogicalClock::get(operationContext())->getClusterTime().getTime();
-    auto keyStatus = updater.refresh(operationContext());
-    // TODO: Inspect keyStatus once SERVER-28435 is implemented
-
-    auto allKeys = getKeys(operationContext());
-
-    ASSERT_EQ(4u, allKeys.size());
-
-    auto citer = allKeys.cbegin();
-
-    std::set<std::string> seenKeys;
-
-    {
-        const auto& key = *citer;
-        ASSERT_EQ(1, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey1.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(105, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(2, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey2.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(110, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(currentTime.asTimestamp().asLL(), key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(Timestamp(125, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(currentTime.asTimestamp().asLL() + 1, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_NE(origKey1.getKey(), key.getKey());
-        ASSERT_NE(origKey2.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(130, 0), key.getExpiresAt().asTimestamp());
-
-        bool inserted = false;
-        std::tie(std::ignore, inserted) = seenKeys.insert(key.getKey().toString());
-        ASSERT_TRUE(inserted);
-    }
-}
-
-TEST_F(CacheUpdaterTest, ShouldNotCreateNewKeyIfThereAre2UnexpiredKeys) {
-    KeysCollectionCacheReaderAndUpdater updater("dummy", Seconds(5));
-
-    LogicalClock::get(operationContext())
-        ->initClusterTimeFromTrustedSource(LogicalTime(Timestamp(100, 2)));
-
-    KeysCollectionDocument origKey1(
-        1, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(105, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey1.toBSON()));
-
-    KeysCollectionDocument origKey2(
-        2, "dummy", TimeProofService::generateRandomKey(), LogicalTime(Timestamp(110, 0)));
-    ASSERT_OK(insertToConfigCollection(
-        operationContext(), NamespaceString(KeysCollectionDocument::ConfigNS), origKey2.toBSON()));
-
-    {
-        auto allKeys = getKeys(operationContext());
-
-        ASSERT_EQ(2u, allKeys.size());
-
-        const auto& key1 = allKeys.front();
-        ASSERT_EQ(1, key1.getKeyId());
-        ASSERT_EQ("dummy", key1.getPurpose());
-        ASSERT_EQ(Timestamp(105, 0), key1.getExpiresAt().asTimestamp());
-
-        const auto& key2 = allKeys.back();
-        ASSERT_EQ(2, key2.getKeyId());
-        ASSERT_EQ("dummy", key2.getPurpose());
-        ASSERT_EQ(Timestamp(110, 0), key2.getExpiresAt().asTimestamp());
-    }
-
-    auto keyStatus = updater.refresh(operationContext());
-    // TODO: Inspect keyStatus once SERVER-28435 is implemented
-
-    auto allKeys = getKeys(operationContext());
-
-    ASSERT_EQ(2u, allKeys.size());
-
-    auto citer = allKeys.cbegin();
-
-    {
-        const auto& key = *citer;
-        ASSERT_EQ(1, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey1.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(105, 0), key.getExpiresAt().asTimestamp());
-    }
-
-    {
-        ++citer;
-        const auto& key = *citer;
-        ASSERT_EQ(2, key.getKeyId());
-        ASSERT_EQ("dummy", key.getPurpose());
-        ASSERT_EQ(origKey2.getKey(), key.getKey());
-        ASSERT_EQ(Timestamp(110, 0), key.getExpiresAt().asTimestamp());
-    }
-}
-
-}  // namespace mongo
diff --git a/src/mongo/db/ops/insert.cpp b/src/mongo/db/ops/insert.cpp
index c448126eca7..f856c227138 100644
--- a/src/mongo/db/ops/insert.cpp
+++ b/src/mongo/db/ops/insert.cpp
@@ -241,8 +241,6 @@ Status userAllowedCreateNS(StringData db, StringData coll) {
                 return Status::OK();
             if (coll == "system.backup_users")
                 return Status::OK();
-            if (coll == "system.keys")
-                return Status::OK();
         }
         if (db == "local") {
             if (coll == "system.replset")
diff --git a/src/mongo/s/catalog/sharding_catalog_client_impl.cpp b/src/mongo/s/catalog/sharding_catalog_client_impl.cpp
index 0c97211ca34..8495c5f6b07 100644
--- a/src/mongo/s/catalog/sharding_catalog_client_impl.cpp
+++ b/src/mongo/s/catalog/sharding_catalog_client_impl.cpp
@@ -1518,7 +1518,7 @@ Status ShardingCatalogClientImpl::insertConfigDocument(OperationContext* opCtx,
                                                        const BSONObj& doc,
                                                        const WriteConcernOptions& writeConcern) {
     const NamespaceString nss(ns);
-    invariant(nss.db() == "config" || nss.db() == "admin");
+    invariant(nss.db() == "config");
 
     const BSONElement idField = doc.getField("_id");
     invariant(!idField.eoo());
diff --git a/src/mongo/s/config_server_test_fixture.cpp b/src/mongo/s/config_server_test_fixture.cpp
index c5640333022..4f1e6246646 100644
--- a/src/mongo/s/config_server_test_fixture.cpp
+++ b/src/mongo/s/config_server_test_fixture.cpp
@@ -292,27 +292,5 @@ StatusWith<std::vector<BSONObj>> ConfigServerTestFixture::getIndexes(OperationCo
     return cursorResponse.getValue().getBatch();
 }
 
-std::vector<KeysCollectionDocument> ConfigServerTestFixture::getKeys(OperationContext* opCtx) {
-    auto config = getConfigShard();
-    auto findStatus =
-        config->exhaustiveFindOnConfig(opCtx,
-                                       kReadPref,
-                                       repl::ReadConcernLevel::kMajorityReadConcern,
-                                       NamespaceString(KeysCollectionDocument::ConfigNS),
-                                       BSONObj(),
-                                       BSON("expiresAt" << 1),
-                                       boost::none);
-    ASSERT_OK(findStatus.getStatus());
-
-    std::vector<KeysCollectionDocument> keys;
-    const auto& docs = findStatus.getValue().docs;
-    for (const auto& doc : docs) {
-        auto keyStatus = KeysCollectionDocument::fromBSON(doc);
-        ASSERT_OK(keyStatus.getStatus());
-        keys.push_back(keyStatus.getValue());
-    }
-
-    return keys;
-}
 
 }  // namespace mongo
diff --git a/src/mongo/s/config_server_test_fixture.h b/src/mongo/s/config_server_test_fixture.h
index 69d08afe17d..411b3672902 100644
--- a/src/mongo/s/config_server_test_fixture.h
+++ b/src/mongo/s/config_server_test_fixture.h
@@ -34,7 +34,6 @@ namespace mongo {
 
 class BSONObj;
 class ChunkType;
-class KeysCollectionDocument;
 class NamespaceString;
 class Shard;
 class ShardingCatalogClient;
@@ -110,11 +109,6 @@ public:
      */
     void onCommandForAddShard(executor::NetworkTestEnv::OnCommandFunction func);
 
-    /**
-     * Returns all the keys in admin.system.keys
-     */
-    std::vector<KeysCollectionDocument> getKeys(OperationContext* opCtx);
-
 protected:
     /**
      * Sets this node up as a mongod with sharding components for ClusterRole::ConfigServer.