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-rw-r--r--src/mongo/SConscript4
-rw-r--r--src/mongo/db/SConscript13
-rw-r--r--src/mongo/db/commands/SConscript3
-rw-r--r--src/mongo/db/commands/rwc_defaults_commands.cpp2
-rw-r--r--src/mongo/db/db.cpp3
-rw-r--r--src/mongo/db/dist_cache.h408
-rw-r--r--src/mongo/db/read_write_concern_defaults.cpp73
-rw-r--r--src/mongo/db/read_write_concern_defaults.h39
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mock.cpp47
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mock.h54
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.cpp39
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.h43
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.cpp39
-rw-r--r--src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.h42
-rw-r--r--src/mongo/db/service_entry_point_common.cpp2
-rw-r--r--src/mongo/db/write_concern.cpp2
-rw-r--r--src/mongo/embedded/SConscript1
-rw-r--r--src/mongo/embedded/embedded.cpp3
-rw-r--r--src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.cpp39
-rw-r--r--src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.h42
-rw-r--r--src/mongo/s/commands/strategy.cpp4
-rw-r--r--src/mongo/s/server.cpp3
22 files changed, 858 insertions, 47 deletions
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index fa3f27e5b14..8a1a2690dc6 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -354,6 +354,7 @@ mongod = env.Program(
target="mongod",
source=[
"db/db.cpp",
+ "db/read_write_concern_defaults_cache_lookup_mongod.cpp",
] + env.WindowsResourceFile("db/db.rc"),
LIBDEPS=[
'$BUILD_DIR/third_party/shim_snappy',
@@ -404,6 +405,7 @@ mongod = env.Program(
'db/pipeline/process_interface_factory_mongod',
'db/query_exec',
'db/read_concern_d_impl',
+ 'db/read_write_concern_defaults',
'db/repair_database_and_check_version',
'db/repl/bgsync',
'db/repl/oplog_application',
@@ -522,6 +524,7 @@ if not hygienic:
mongos = env.Program(
target='mongos',
source=[
+ "db/read_write_concern_defaults_cache_lookup_mongos.cpp",
's/cluster_cursor_stats.cpp',
's/mongos_options.cpp',
's/mongos_options_init.cpp',
@@ -545,6 +548,7 @@ mongos = env.Program(
'db/logical_session_cache',
'db/logical_session_cache_impl',
'db/logical_time_metadata_hook',
+ 'db/read_write_concern_defaults',
'db/server_options',
'db/server_options_base',
'db/service_liaison_mongos',
diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 6d5be85cbcc..04bdfba8274 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -59,7 +59,6 @@ env.Library(
'$BUILD_DIR/mongo/base',
'$BUILD_DIR/mongo/db/index_names',
'$BUILD_DIR/mongo/db/write_concern_options',
- '$BUILD_DIR/mongo/db/read_write_concern_defaults',
]
)
@@ -386,6 +385,16 @@ env.Library(
)
env.Library(
+ target="read_write_concern_defaults_mock",
+ source=[
+ "read_write_concern_defaults_cache_lookup_mock.cpp",
+ ],
+ LIBDEPS=[
+ 'read_write_concern_defaults',
+ ],
+)
+
+env.Library(
target='service_context',
source=[
'baton.cpp',
@@ -874,6 +883,7 @@ env.Library(
"concurrency/lock_manager",
"concurrency/write_conflict_exception",
"curop",
+ 'read_write_concern_defaults',
"repl/read_concern_args",
"repl/repl_coordinator_interface",
"repl/speculative_majority_read_info",
@@ -1810,6 +1820,7 @@ envWithAsio.CppUnitTest(
'op_observer_impl',
'query_exec',
'range_arithmetic',
+ 'read_write_concern_defaults_mock',
'repl/mock_repl_coord_server_fixture',
'repl/oplog_interface_local',
'repl/repl_coordinator_interface',
diff --git a/src/mongo/db/commands/SConscript b/src/mongo/db/commands/SConscript
index 38c77097e9f..3bdfb73e08d 100644
--- a/src/mongo/db/commands/SConscript
+++ b/src/mongo/db/commands/SConscript
@@ -148,6 +148,9 @@ env.Library(
env.Idlc('drop_connections.idl')[0],
env.Idlc('rwc_defaults_commands.idl')[0],
],
+ LIBDEPS=[
+ '$BUILD_DIR/mongo/db/read_write_concern_defaults',
+ ],
LIBDEPS_PRIVATE=[
'$BUILD_DIR/mongo/client/clientdriver_minimal',
'$BUILD_DIR/mongo/db/commands',
diff --git a/src/mongo/db/commands/rwc_defaults_commands.cpp b/src/mongo/db/commands/rwc_defaults_commands.cpp
index 3389cbe79b2..e251d4dfdc5 100644
--- a/src/mongo/db/commands/rwc_defaults_commands.cpp
+++ b/src/mongo/db/commands/rwc_defaults_commands.cpp
@@ -113,7 +113,7 @@ public:
auto typedRun(OperationContext* opCtx) {
auto& rwcDefaults = ReadWriteConcernDefaults::get(opCtx->getServiceContext());
- return rwcDefaults.getDefault();
+ return rwcDefaults.getDefault(opCtx);
}
private:
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index bc669196f8c..fb02bce6ed4 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -102,6 +102,7 @@
#include "mongo/db/periodic_runner_job_abort_expired_transactions.h"
#include "mongo/db/periodic_runner_job_decrease_snapshot_cache_pressure.h"
#include "mongo/db/query/internal_plans.h"
+#include "mongo/db/read_write_concern_defaults_cache_lookup_mongod.h"
#include "mongo/db/repair_database_and_check_version.h"
#include "mongo/db/repl/drop_pending_collection_reaper.h"
#include "mongo/db/repl/oplog.h"
@@ -1092,6 +1093,8 @@ int mongoDbMain(int argc, char* argv[], char** envp) {
// initializeServerGlobalState) and before the creation of any other threads
startSignalProcessingThread();
+ ReadWriteConcernDefaults::create(service, readWriteConcernDefaultsCacheLookupMongoD);
+
#if defined(_WIN32)
if (ntservice::shouldStartService()) {
ntservice::startService();
diff --git a/src/mongo/db/dist_cache.h b/src/mongo/db/dist_cache.h
new file mode 100644
index 00000000000..b2b7beb8302
--- /dev/null
+++ b/src/mongo/db/dist_cache.h
@@ -0,0 +1,408 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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 <boost/optional.hpp>
+
+#include "mongo/bson/oid.h"
+#include "mongo/platform/mutex.h"
+#include "mongo/stdx/condition_variable.h"
+#include "mongo/util/invalidating_lru_cache.h"
+
+namespace mongo {
+
+class OperationContext;
+
+/**
+ * A server's cache of cluster-wide information.
+ */
+template <typename Key, typename UnderlyingValue>
+class DistCache {
+public:
+ /**
+ * Wrapper around Value that adds an atomic bool to indicate validity.
+ *
+ * Every Value object is owned by a DistCache. The DistCache is the only one that should
+ * construct, modify, or delete a Value object. All other consumers of Value only get const
+ * access to the underlying value. The DistCache is responsible for maintaining the reference
+ * count on all Value objects it gives out and must not mutate any Value objects with a non-zero
+ * reference count (except to call invalidate()). Any consumer of a Value object should check
+ * isValid() before using it, and if it has been invalidated, it should return the object to the
+ * DistCache and fetch a new Value object instance for this Key from the DistCache.
+ */
+ class Value {
+ Value(const Value&) = delete;
+ Value& operator=(const Value&) = delete;
+
+ public:
+ explicit Value(UnderlyingValue&& underlyingValue)
+ : _underlyingValue(std::move(underlyingValue)) {}
+
+ UnderlyingValue& operator*() {
+ return _underlyingValue;
+ }
+
+ const UnderlyingValue& operator*() const {
+ return _underlyingValue;
+ }
+
+ /**
+ * Returns true if this copy of information about this value is still valid. If this returns
+ * false, this object should no longer be used and should be returned to the
+ * DistCache and a new Value object for this Key should be requested.
+ */
+ bool isValid() const {
+ return _isValid.loadRelaxed();
+ }
+
+ private:
+ friend class DistCache;
+
+ /**
+ * Marks this instance of the Value object as invalid, most likely because the underlying
+ * value has been updated and needs to be reloaded by the DistCache.
+ *
+ * This method should *only* be called by the DistCache.
+ */
+ void _invalidate() {
+ _isValid.store(false);
+ }
+
+ // The underlying value.
+ UnderlyingValue _underlyingValue;
+
+ // Indicates whether the value has been marked as invalid by the DistCache.
+ AtomicWord<bool> _isValid{true};
+ };
+
+ using ValueHandle = std::shared_ptr<Value>;
+
+ DistCache(const DistCache&) = delete;
+ DistCache& operator=(const DistCache&) = delete;
+
+ virtual ~DistCache() = default;
+
+ /**
+ * Returns the cache generation identifier.
+ */
+ OID getCacheGeneration() {
+ stdx::lock_guard<Latch> lk(_cacheWriteMutex);
+ return _fetchGeneration;
+ }
+
+ /**
+ * Returns a ValueHandle for the given Key. If there is no entry for this key, then returns
+ * boost::none. If the cache already has a value for this key, it returns a handle from the
+ * cache, otherwise it obtains the value from the Lookup - this may block for a long time.
+ *
+ * The returned value may be invalid by the time the caller gets access to it.
+ */
+ boost::optional<ValueHandle> acquire(OperationContext* opCtx, const Key& key) {
+ boost::optional<ValueHandle> cachedValue = _cache.get(key);
+
+ // The _cache is thread-safe, so if we can get a Value out of the cache we don't need to
+ // take any locks!
+ if (cachedValue) {
+ invariant(*cachedValue);
+ return *cachedValue;
+ }
+
+ // Otherwise make sure we have the locks we need and check whether and wait on another
+ // thread is fetching into the cache
+ CacheGuard guard(this);
+
+ while (!(cachedValue = _cache.get(key)) && guard.otherUpdateInFetchPhase()) {
+ guard.wait();
+ }
+
+ if (cachedValue) {
+ invariant(*cachedValue);
+ return *cachedValue;
+ }
+
+ // If there's still no value in the cache, then we need to go and get it. Take the slow
+ // path.
+
+ guard.beginFetchPhase();
+
+ auto underlyingValue = lookup(opCtx, key);
+ if (!underlyingValue)
+ return boost::none;
+ auto value = std::make_unique<Value>(std::move(*underlyingValue));
+
+ // All this does is re-acquire the _cacheWriteMutex if we don't hold it already - a caller
+ // may also call endFetchPhase() after this returns.
+ guard.endFetchPhase();
+
+ ValueHandle ret;
+ if (guard.isSameCacheGeneration()) {
+ ret = _cache.insertOrAssignAndGet(key, std::move(value));
+ } else {
+ // If the cache generation changed while this thread was in fetch mode, the data
+ // associated with the value may now be invalid, so we must mark it as such. The caller
+ // may still opt to use the information for a short while, but not indefinitely.
+ value->_invalidate();
+ ret = ValueHandle(std::move(value));
+ }
+
+ return ret;
+ }
+
+ /**
+ * Marks the given value as invalid and removes it from the cache.
+ */
+ void invalidate(const Key& key) {
+ CacheGuard guard(this);
+ _updateCacheGeneration(guard);
+ _cache.invalidate(key);
+ }
+
+ template <typename Pred>
+ void invalidateIf(const Pred& predicate) {
+ CacheGuard guard(this);
+ _updateCacheGeneration(guard);
+ _cache.invalidateIf(
+ [&](const Key& key, const Value* value) { return predicate(key, &(*(*value))); });
+ }
+
+ /**
+ * Invalidates the given value and immediately replaces it with a new value.
+ */
+ ValueHandle revalidate(const Key& key, UnderlyingValue&& newUnderlyingValue) {
+ CacheGuard guard(this);
+
+ // Invalidate the old value.
+ _cache.invalidate(key);
+
+ // Put the new value into the cache.
+ auto newValue = std::make_unique<Value>(std::move(newUnderlyingValue));
+ ValueHandle ret = _cache.insertOrAssignAndGet(key, std::move(newValue));
+
+ // Update the cache generation.
+ _updateCacheGeneration(guard);
+
+ return ret;
+ }
+
+ /**
+ * Invalidates all Value objects in the cache and removes them from the cache.
+ */
+ void invalidateCache() {
+ CacheGuard guard(this);
+ _updateCacheGeneration(guard);
+ _cache.invalidateIf([](const Key& a, const Value*) { return true; });
+ }
+
+protected:
+ /**
+ * DistCache constructor, to be called by sub-classes. Accepts the initial size of the cache,
+ * and a reference to a Mutex. The Mutex is for the exclusive use of the DistCache, the
+ * sub-class should never actually use it (apart from passing it to this constructor). Having
+ * the Mutex stored by the sub-class allows latch diagnostics to be correctly associated with
+ * the sub-class (not the generic DistCache class).
+ */
+ DistCache(int cacheSize, Mutex& mutex)
+ : _cache(cacheSize, Invalidator()), _cacheWriteMutex(mutex), _fetchGeneration(OID::gen()) {}
+
+private:
+ /**
+ * Type used to guard accesses and updates to the cache.
+ *
+ * Guard object for synchronizing accesses to data cached in DistCache instances.
+ * This guard allows one thread to access the cache at a time, and provides an exception-safe
+ * mechanism for a thread to release the cache mutex while performing network or disk operations
+ * while allowing other readers to proceed.
+ *
+ * There are two ways to use this guard. One may simply instantiate the guard like a
+ * std::lock_guard, and perform reads or writes of the cache.
+ *
+ * Alternatively, one may instantiate the guard, examine the cache, and then enter into an
+ * update mode by first wait()ing until otherUpdateInFetchPhase() is false, and then
+ * calling beginFetchPhase(). At this point, other threads may acquire the guard in the simple
+ * manner and do reads, but other threads may not enter into a fetch phase. During the fetch
+ * phase, the thread should perform required network or disk activity to determine what update
+ * it will make to the cache. Then, it should call endFetchPhase(), to reacquire the cache
+ * mutex. At that point, the thread can make its modifications to the cache and let the guard
+ * go out of scope.
+ *
+ * All updates by guards using a fetch-phase are totally ordered with respect to one another,
+ * and all guards using no fetch phase are totally ordered with respect to one another, but
+ * there is not a total ordering among all guard objects.
+ *
+ * The cached data has an associated counter, called the cache generation. If the cache
+ * generation changes while a guard is in fetch phase, the fetched data should not be stored
+ * into the cache, because some invalidation event occurred during the fetch phase.
+ */
+ class CacheGuard {
+ CacheGuard(const CacheGuard&) = delete;
+ CacheGuard& operator=(const CacheGuard&) = delete;
+
+ public:
+ /**
+ * Constructs a cache guard, locking the mutex that synchronizes DistCache accesses.
+ */
+ explicit CacheGuard(DistCache* distCache)
+ : _isThisGuardInFetchPhase(false),
+ _distCache(distCache),
+ _cacheLock(distCache->_cacheWriteMutex) {}
+
+ /**
+ * Releases the mutex that synchronizes cache access, if held, and notifies
+ * any threads waiting for their own opportunity to update the cache.
+ */
+ ~CacheGuard() {
+ if (!_cacheLock.owns_lock()) {
+ _cacheLock.lock();
+ }
+ if (_isThisGuardInFetchPhase) {
+ invariant(otherUpdateInFetchPhase());
+ _distCache->_isFetchPhaseBusy = false;
+ _distCache->_fetchPhaseIsReady.notify_all();
+ }
+ }
+
+ /**
+ * Returns true if the distCache reports that it is in fetch phase.
+ */
+ bool otherUpdateInFetchPhase() const {
+ return _distCache->_isFetchPhaseBusy;
+ }
+
+ /**
+ * Waits on the _distCache->_fetchPhaseIsReady condition.
+ */
+ void wait() {
+ invariant(!_isThisGuardInFetchPhase);
+ _distCache->_fetchPhaseIsReady.wait(_cacheLock,
+ [&] { return !otherUpdateInFetchPhase(); });
+ }
+
+ /**
+ * Enters fetch phase, releasing the _distCache->_cacheMutex after recording the current
+ * cache generation.
+ */
+ void beginFetchPhase() {
+ invariant(!otherUpdateInFetchPhase());
+ _isThisGuardInFetchPhase = true;
+ _distCache->_isFetchPhaseBusy = true;
+ _distCacheFetchGenerationAtFetchBegin = _distCache->_fetchGeneration;
+ _cacheLock.unlock();
+ }
+
+ /**
+ * Exits the fetch phase, reacquiring the _distCache->_cacheMutex.
+ */
+ void endFetchPhase() {
+ _cacheLock.lock();
+ // We do not clear _distCache->_isFetchPhaseBusy or notify waiters until
+ // ~CacheGuard(), for two reasons. First, there's no value to notifying the waiters
+ // before you're ready to release the mutex, because they'll just go to sleep on the
+ // mutex. Second, in order to meaningfully check the preconditions of
+ // isSameCacheGeneration(), we need a state that means "fetch phase was entered and now
+ // has been exited." That state is _isThisGuardInFetchPhase == true and
+ // _lock.owns_lock() == true.
+ }
+
+ /**
+ * Returns true if _distCache->_fetchGeneration remained the same while this guard was
+ * in fetch phase. Behavior is undefined if this guard never entered fetch phase.
+ *
+ * If this returns true, do not update the cached data with this
+ */
+ bool isSameCacheGeneration() const {
+ invariant(_isThisGuardInFetchPhase);
+ invariant(_cacheLock.owns_lock());
+ return _distCacheFetchGenerationAtFetchBegin == _distCache->_fetchGeneration;
+ }
+
+ private:
+ OID _distCacheFetchGenerationAtFetchBegin;
+ bool _isThisGuardInFetchPhase;
+ DistCache* _distCache;
+
+ stdx::unique_lock<Latch> _cacheLock;
+ };
+
+ friend class DistCache::CacheGuard;
+
+ class Invalidator {
+ public:
+ void operator()(Value* value) {
+ value->_invalidate();
+ }
+ };
+
+ /**
+ * Provide the value for a key when there is a cache miss. Sub-classes must implement this
+ * function appropriately. Throw a uassertion to indicate an error while looking up the value,
+ * or return value for this key, o rboost::none if this key has no value.
+ */
+ virtual boost::optional<UnderlyingValue> lookup(OperationContext* opCtx, const Key& key) = 0;
+
+ /**
+ * Updates _fetchGeneration to a new OID
+ */
+ void _updateCacheGeneration(const CacheGuard&) {
+ _fetchGeneration = OID::gen();
+ }
+
+ /**
+ * The cache itself is "self-synchronising" (ie. thread-safe), and so does not need to be
+ * protected by _cacheWriteMutex.
+ */
+ InvalidatingLRUCache<Key, Value, Invalidator> _cache;
+
+ /**
+ * Protects _fetchGeneration and _isFetchPhaseBusy. Manipulated via CacheGuard.
+ */
+ Mutex& _cacheWriteMutex;
+
+ /**
+ * Current generation of cached data. Updated every time part of the cache gets
+ * invalidated. Protected by CacheGuard.
+ */
+ OID _fetchGeneration;
+
+ /**
+ * True if there is an update to the _cache in progress, and that update is currently in
+ * the "fetch phase", during which it does not hold the _cacheMutex.
+ *
+ * Manipulated via CacheGuard.
+ */
+ bool _isFetchPhaseBusy = false;
+
+ /**
+ * Condition used to signal that it is OK for another CacheGuard to enter a fetch phase.
+ * Manipulated via CacheGuard.
+ */
+ stdx::condition_variable _fetchPhaseIsReady;
+};
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults.cpp b/src/mongo/db/read_write_concern_defaults.cpp
index 267ee413045..1e2c2197c83 100644
--- a/src/mongo/db/read_write_concern_defaults.cpp
+++ b/src/mongo/db/read_write_concern_defaults.cpp
@@ -76,9 +76,8 @@ void ReadWriteConcernDefaults::checkSuitabilityAsDefault(const WriteConcern& wc)
!(wc.wMode.empty() && wc.wNumNodes < 1));
}
-void ReadWriteConcernDefaults::_setDefault(WithLock, RWConcernDefault&& rwc) {
- _defaults.erase(kReadWriteConcernEntry);
- _defaults.emplace(kReadWriteConcernEntry, rwc);
+void ReadWriteConcernDefaults::_setDefault(RWConcernDefault&& rwc) {
+ _defaults.revalidate(Type::kReadWriteConcernEntry, std::move(rwc));
}
RWConcernDefault ReadWriteConcernDefaults::setConcerns(OperationContext* opCtx,
@@ -103,68 +102,80 @@ RWConcernDefault ReadWriteConcernDefaults::setConcerns(OperationContext* opCtx,
rwc.setSetTime(now);
rwc.setLocalSetTime(now);
- stdx::lock_guard<Latch> lk(_mutex);
-
- auto current = _getDefault(lk);
+ auto current = _getDefault(opCtx);
if (!rc && current) {
rwc.setDefaultReadConcern(current->getDefaultReadConcern());
}
if (!wc && current) {
rwc.setDefaultWriteConcern(current->getDefaultWriteConcern());
}
- _setDefault(lk, std::move(rwc));
- return *_getDefault(lk);
+ _setDefault(std::move(rwc));
+ return *_getDefault(opCtx);
}
void ReadWriteConcernDefaults::invalidate() {
- stdx::lock_guard<Latch> lk(_mutex);
- _defaults.erase(kReadWriteConcernEntry);
+ _defaults.invalidate(Type::kReadWriteConcernEntry);
}
-boost::optional<RWConcernDefault> ReadWriteConcernDefaults::_getDefault(WithLock) const {
- if (_defaults.find(kReadWriteConcernEntry) == _defaults.end()) {
- return boost::none;
+boost::optional<RWConcernDefault> ReadWriteConcernDefaults::_getDefault(OperationContext* opCtx) {
+ auto defaultsHandle = _defaults.acquire(opCtx, Type::kReadWriteConcernEntry);
+ if (defaultsHandle) {
+ auto& defaultsValue = **defaultsHandle;
+ // Since CWRWC is ok with continuing to use a value well after it has been invalidated
+ // (since RWC defaults apply for the lifetime of the op/cursor), we don't need to check
+ // defaultsValue.isValid() here, and we don't need to return the Handle, since callers don't
+ // need to check defaultsValue.isValid() later, either. Just dereference it to get the
+ // underlying contents.
+ return *defaultsValue;
}
- return _defaults.at(kReadWriteConcernEntry);
+ return boost::none;
}
-RWConcernDefault ReadWriteConcernDefaults::getDefault() const {
- auto current = ([&]() {
- stdx::lock_guard<Latch> lk(_mutex);
- return _getDefault(lk);
- })();
- if (!current) {
- return RWConcernDefault{};
- }
- return *current;
+RWConcernDefault ReadWriteConcernDefaults::getDefault(OperationContext* opCtx) {
+ return _getDefault(opCtx).value_or(RWConcernDefault());
}
boost::optional<ReadWriteConcernDefaults::ReadConcern>
-ReadWriteConcernDefaults::getDefaultReadConcern() const {
- auto current = getDefault();
+ReadWriteConcernDefaults::getDefaultReadConcern(OperationContext* opCtx) {
+ auto current = getDefault(opCtx);
return current.getDefaultReadConcern();
}
boost::optional<ReadWriteConcernDefaults::WriteConcern>
-ReadWriteConcernDefaults::getDefaultWriteConcern() const {
- auto current = getDefault();
+ReadWriteConcernDefaults::getDefaultWriteConcern(OperationContext* opCtx) {
+ auto current = getDefault(opCtx);
return current.getDefaultWriteConcern();
}
-
namespace {
const auto getReadWriteConcernDefaults =
- ServiceContext::declareDecoration<ReadWriteConcernDefaults>();
+ ServiceContext::declareDecoration<std::unique_ptr<ReadWriteConcernDefaults>>();
} // namespace
ReadWriteConcernDefaults& ReadWriteConcernDefaults::get(ServiceContext* service) {
- return getReadWriteConcernDefaults(service);
+ return *getReadWriteConcernDefaults(service);
}
ReadWriteConcernDefaults& ReadWriteConcernDefaults::get(ServiceContext& service) {
- return getReadWriteConcernDefaults(service);
+ return *getReadWriteConcernDefaults(service);
+}
+
+void ReadWriteConcernDefaults::create(ServiceContext* service, LookupFn lookupFn) {
+ getReadWriteConcernDefaults(service) = std::make_unique<ReadWriteConcernDefaults>(lookupFn);
+}
+
+ReadWriteConcernDefaults::ReadWriteConcernDefaults(LookupFn lookupFn) : _defaults(lookupFn) {}
+
+ReadWriteConcernDefaults::Cache::Cache(LookupFn lookupFn)
+ : DistCache(1, _mutex), _lookupFn(lookupFn) {}
+
+boost::optional<RWConcernDefault> ReadWriteConcernDefaults::Cache::lookup(
+ OperationContext* opCtx, const ReadWriteConcernDefaults::Type& key) {
+ invariant(key == Type::kReadWriteConcernEntry);
+ // TODO: failpoint to uassert a custom Status
+ return _lookupFn(opCtx);
}
} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults.h b/src/mongo/db/read_write_concern_defaults.h
index cb8b6386ae8..de21b27836d 100644
--- a/src/mongo/db/read_write_concern_defaults.h
+++ b/src/mongo/db/read_write_concern_defaults.h
@@ -31,6 +31,7 @@
#include <map>
+#include "mongo/db/dist_cache.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/read_concern_args.h"
#include "mongo/db/rw_concern_default_gen.h"
@@ -52,13 +53,17 @@ public:
using ReadConcern = repl::ReadConcernArgs;
using WriteConcern = WriteConcernOptions;
+ using LookupFn = std::function<boost::optional<RWConcernDefault>(OperationContext*)>;
+
static constexpr StringData readConcernFieldName = ReadConcern::kReadConcernFieldName;
static constexpr StringData writeConcernFieldName = WriteConcern::kWriteConcernField;
static ReadWriteConcernDefaults& get(ServiceContext* service);
static ReadWriteConcernDefaults& get(ServiceContext& service);
+ static void create(ServiceContext* service, LookupFn lookupFn);
- ReadWriteConcernDefaults() = default;
+ ReadWriteConcernDefaults() = delete;
+ ReadWriteConcernDefaults(LookupFn lookupFn);
~ReadWriteConcernDefaults() = default;
/**
@@ -92,20 +97,34 @@ public:
*/
void invalidate();
- RWConcernDefault getDefault() const;
- boost::optional<ReadConcern> getDefaultReadConcern() const;
- boost::optional<WriteConcern> getDefaultWriteConcern() const;
+ RWConcernDefault getDefault(OperationContext* opCtx);
+ boost::optional<ReadConcern> getDefaultReadConcern(OperationContext* opCtx);
+ boost::optional<WriteConcern> getDefaultWriteConcern(OperationContext* opCtx);
private:
- enum Type { kReadWriteConcernEntry };
+ enum class Type { kReadWriteConcernEntry };
+
+ void _setDefault(RWConcernDefault&& rwc);
+ boost::optional<RWConcernDefault> _getDefault(OperationContext* opCtx);
+
+ class Cache : public DistCache<Type, RWConcernDefault> {
+ Cache(const Cache&) = delete;
+ Cache& operator=(const Cache&) = delete;
+
+ public:
+ Cache(LookupFn lookupFn);
+ virtual ~Cache() = default;
+
+ private:
+ boost::optional<RWConcernDefault> lookup(OperationContext* opCtx, const Type& key) override;
- void _setDefault(WithLock, RWConcernDefault&& rwc);
- boost::optional<RWConcernDefault> _getDefault(WithLock) const;
+ // For exclusive use by DistCache only.
+ Mutex _mutex = MONGO_MAKE_LATCH("ReadWriteConcernDefaults::Cache");
- // Protects access to the private members below.
- mutable Mutex _mutex = MONGO_MAKE_LATCH("ReadWriteConcernDefaults::_mutex");
+ LookupFn _lookupFn;
+ };
- std::map<Type, RWConcernDefault> _defaults;
+ Cache _defaults;
};
} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.cpp b/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.cpp
new file mode 100644
index 00000000000..2a6b14cd18b
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.cpp
@@ -0,0 +1,47 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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/db/read_write_concern_defaults_cache_lookup_mock.h"
+
+namespace mongo {
+
+ReadWriteConcernDefaults::LookupFn ReadWriteConcernDefaultsLookupMock::getLookupFn() {
+ return std::bind(&ReadWriteConcernDefaultsLookupMock::lookup, this, std::placeholders::_1);
+}
+
+boost::optional<RWConcernDefault> ReadWriteConcernDefaultsLookupMock::lookup(
+ OperationContext* opCtx) {
+ return _value;
+}
+
+void ReadWriteConcernDefaultsLookupMock::setLookupCallReturnValue(RWConcernDefault&& rwc) {
+ _value.emplace(rwc);
+}
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.h b/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.h
new file mode 100644
index 00000000000..7913f576ef4
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mock.h
@@ -0,0 +1,54 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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 "mongo/db/read_write_concern_defaults.h"
+
+namespace mongo {
+
+/**
+ * A class which handles looking up RWConcernDefault values from an in-memory location.
+ */
+class ReadWriteConcernDefaultsLookupMock {
+public:
+ ReadWriteConcernDefaults::LookupFn getLookupFn();
+
+ boost::optional<RWConcernDefault> lookup(OperationContext* opCtx);
+
+ /**
+ * Behind-the-scenes way to update the stored in-memory value that lookup() returns.
+ */
+ void setLookupCallReturnValue(RWConcernDefault&& value);
+
+private:
+ boost::optional<RWConcernDefault> _value;
+};
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.cpp b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.cpp
new file mode 100644
index 00000000000..f807f67c204
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.cpp
@@ -0,0 +1,39 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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/db/read_write_concern_defaults_cache_lookup_mongod.h"
+
+namespace mongo {
+
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupMongoD(
+ OperationContext* opCtx) {
+ return boost::none;
+}
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.h b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.h
new file mode 100644
index 00000000000..44306249a1c
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongod.h
@@ -0,0 +1,43 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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 "mongo/db/read_write_concern_defaults.h"
+
+namespace mongo {
+
+/**
+ * A function which handles looking up RWConcernDefault values from where they are persisted in
+ * config.settings.
+ */
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupMongoD(
+ OperationContext* opCtx);
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.cpp b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.cpp
new file mode 100644
index 00000000000..907d804cce8
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.cpp
@@ -0,0 +1,39 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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/db/read_write_concern_defaults_cache_lookup_mongos.h"
+
+namespace mongo {
+
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupMongoS(
+ OperationContext* opCtx) {
+ return boost::none;
+}
+
+} // namespace mongo
diff --git a/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.h b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.h
new file mode 100644
index 00000000000..d99b076e6f7
--- /dev/null
+++ b/src/mongo/db/read_write_concern_defaults_cache_lookup_mongos.h
@@ -0,0 +1,42 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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 "mongo/db/read_write_concern_defaults.h"
+
+namespace mongo {
+
+/**
+ * A function which handles looking up RWConcernDefault values from config servers.
+ */
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupMongoS(
+ OperationContext* opCtx);
+
+} // namespace mongo
diff --git a/src/mongo/db/service_entry_point_common.cpp b/src/mongo/db/service_entry_point_common.cpp
index 58db096f7c0..7bbbe76d453 100644
--- a/src/mongo/db/service_entry_point_common.cpp
+++ b/src/mongo/db/service_entry_point_common.cpp
@@ -260,7 +260,7 @@ StatusWith<repl::ReadConcernArgs> _extractReadConcern(OperationContext* opCtx,
// since this covers both isSpecified() && !isSpecified()
if (readConcernArgs.isEmpty()) {
const auto rcDefault = ReadWriteConcernDefaults::get(opCtx->getServiceContext())
- .getDefaultReadConcern();
+ .getDefaultReadConcern(opCtx);
if (rcDefault) {
readConcernArgs = std::move(*rcDefault);
LOG(2) << "Applying default readConcern on "
diff --git a/src/mongo/db/write_concern.cpp b/src/mongo/db/write_concern.cpp
index 0dcc0ddd57f..2b532fed21e 100644
--- a/src/mongo/db/write_concern.cpp
+++ b/src/mongo/db/write_concern.cpp
@@ -91,7 +91,7 @@ StatusWith<WriteConcernOptions> extractWriteConcern(OperationContext* opCtx,
serverGlobalParams.clusterRole != ClusterRole::ConfigServer &&
!opCtx->getClient()->isInDirectClient()) {
auto wcDefault = ReadWriteConcernDefaults::get(opCtx->getServiceContext())
- .getDefaultWriteConcern();
+ .getDefaultWriteConcern(opCtx);
if (wcDefault) {
LOG(2) << "Applying default writeConcern on " << cmdObj.firstElementFieldName()
<< " of " << wcDefault->toBSON();
diff --git a/src/mongo/embedded/SConscript b/src/mongo/embedded/SConscript
index 09da019b4a8..49baf7939e9 100644
--- a/src/mongo/embedded/SConscript
+++ b/src/mongo/embedded/SConscript
@@ -75,6 +75,7 @@ env.Library(
'periodic_runner_embedded.cpp',
'process_interface_factory_embedded.cpp',
'read_concern_embedded.cpp',
+ 'read_write_concern_defaults_cache_lookup_embedded.cpp',
'replication_coordinator_embedded.cpp',
'service_entry_point_embedded.cpp',
'transaction_coordinator_factory_embedded.cpp',
diff --git a/src/mongo/embedded/embedded.cpp b/src/mongo/embedded/embedded.cpp
index 14df124c6c6..69911b0fa21 100644
--- a/src/mongo/embedded/embedded.cpp
+++ b/src/mongo/embedded/embedded.cpp
@@ -62,6 +62,7 @@
#include "mongo/db/ttl.h"
#include "mongo/embedded/index_builds_coordinator_embedded.h"
#include "mongo/embedded/periodic_runner_embedded.h"
+#include "mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.h"
#include "mongo/embedded/replication_coordinator_embedded.h"
#include "mongo/embedded/service_entry_point_embedded.h"
#include "mongo/logger/log_component.h"
@@ -270,6 +271,8 @@ ServiceContext* initialize(const char* yaml_config) {
boost::filesystem::remove_all(storageGlobalParams.dbpath + "/_tmp/");
}
+ ReadWriteConcernDefaults::create(serviceContext, readWriteConcernDefaultsCacheLookupEmbedded);
+
auto startupOpCtx = serviceContext->makeOperationContext(&cc());
bool canCallFCVSetIfCleanStartup =
diff --git a/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.cpp b/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.cpp
new file mode 100644
index 00000000000..316056e684b
--- /dev/null
+++ b/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.cpp
@@ -0,0 +1,39 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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/embedded/read_write_concern_defaults_cache_lookup_embedded.h"
+
+namespace mongo {
+
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupEmbedded(
+ OperationContext* opCtx) {
+ return boost::none;
+}
+
+} // namespace mongo
diff --git a/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.h b/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.h
new file mode 100644
index 00000000000..d9fb9e2dbca
--- /dev/null
+++ b/src/mongo/embedded/read_write_concern_defaults_cache_lookup_embedded.h
@@ -0,0 +1,42 @@
+/**
+ * Copyright (C) 2019-present MongoDB, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Server Side Public License, version 1,
+ * as published by MongoDB, Inc.
+ *
+ * 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
+ * Server Side Public License for more details.
+ *
+ * You should have received a copy of the Server Side Public License
+ * along with this program. If not, see
+ * <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ * 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 Server Side 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 "mongo/db/read_write_concern_defaults.h"
+
+namespace mongo {
+
+/**
+ * A function which handles looking up RWConcernDefault values on embedded.
+ */
+boost::optional<RWConcernDefault> readWriteConcernDefaultsCacheLookupEmbedded(
+ OperationContext* opCtx);
+
+} // namespace mongo
diff --git a/src/mongo/s/commands/strategy.cpp b/src/mongo/s/commands/strategy.cpp
index 5625c83f37c..db3a8810f22 100644
--- a/src/mongo/s/commands/strategy.cpp
+++ b/src/mongo/s/commands/strategy.cpp
@@ -441,7 +441,7 @@ void runCommand(OperationContext* opCtx,
// This command supports WC, but wasn't given one - so apply the default, if there is
// one.
if (const auto wcDefault = ReadWriteConcernDefaults::get(opCtx->getServiceContext())
- .getDefaultWriteConcern()) {
+ .getDefaultWriteConcern(opCtx)) {
wc = *wcDefault;
LOG(2) << "Applying default writeConcern on " << request.getCommandName() << " of "
<< wcDefault->toBSON();
@@ -461,7 +461,7 @@ void runCommand(OperationContext* opCtx,
(startTransaction || !TransactionRouter::get(opCtx))) {
if (readConcernArgs.isEmpty()) {
const auto rcDefault = ReadWriteConcernDefaults::get(opCtx->getServiceContext())
- .getDefaultReadConcern();
+ .getDefaultReadConcern(opCtx);
if (rcDefault) {
{
// We must obtain the client lock to set ReadConcernArgs, because it's an
diff --git a/src/mongo/s/server.cpp b/src/mongo/s/server.cpp
index ddc851749fe..1870814d80e 100644
--- a/src/mongo/s/server.cpp
+++ b/src/mongo/s/server.cpp
@@ -60,6 +60,7 @@
#include "mongo/db/logical_time_metadata_hook.h"
#include "mongo/db/logical_time_validator.h"
#include "mongo/db/operation_context.h"
+#include "mongo/db/read_write_concern_defaults_cache_lookup_mongos.h"
#include "mongo/db/server_options.h"
#include "mongo/db/service_context.h"
#include "mongo/db/service_liaison_mongos.h"
@@ -550,6 +551,8 @@ ExitCode runMongosServer(ServiceContext* serviceContext) {
LogicalClock::set(serviceContext, std::make_unique<LogicalClock>(serviceContext));
+ ReadWriteConcernDefaults::create(serviceContext, readWriteConcernDefaultsCacheLookupMongoS);
+
auto opCtxHolder = tc->makeOperationContext();
auto const opCtx = opCtxHolder.get();