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/**
* Copyright (C) 2018-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/s/operation_sharding_state.h"
#include "mongo/db/s/sharding_api_d_params_gen.h"
namespace mongo {
namespace {
const OperationContext::Decoration<OperationShardingState> shardingMetadataDecoration =
OperationContext::declareDecoration<OperationShardingState>();
} // namespace
OperationShardingState::OperationShardingState() = default;
OperationShardingState::~OperationShardingState() {
invariant(!_shardingOperationFailedStatus);
}
OperationShardingState& OperationShardingState::get(OperationContext* opCtx) {
return shardingMetadataDecoration(opCtx);
}
bool OperationShardingState::isComingFromRouter(OperationContext* opCtx) {
const auto& oss = get(opCtx);
return !oss._databaseVersions.empty() || !oss._shardVersions.empty();
}
void OperationShardingState::setShardRole(OperationContext* opCtx,
const NamespaceString& nss,
const boost::optional<ShardVersion>& shardVersion,
const boost::optional<DatabaseVersion>& databaseVersion) {
auto& oss = OperationShardingState::get(opCtx);
if (shardVersion) {
auto emplaceResult = oss._shardVersions.try_emplace(nss.ns(), *shardVersion);
auto& tracker = emplaceResult.first->second;
if (!emplaceResult.second) {
uassert(640570,
str::stream() << "Illegal attempt to change the expected shard version for "
<< nss.toStringForErrorMsg() << " from " << tracker.v << " to "
<< *shardVersion,
tracker.v == *shardVersion);
}
invariant(++tracker.recursion > 0);
}
if (databaseVersion) {
auto emplaceResult = oss._databaseVersions.try_emplace(nss.db(), *databaseVersion);
auto& tracker = emplaceResult.first->second;
if (!emplaceResult.second) {
uassert(640571,
str::stream() << "Illegal attempt to change the expected database version for "
<< nss.dbName().toStringForErrorMsg() << " from " << tracker.v
<< " to " << *databaseVersion,
tracker.v == *databaseVersion);
}
invariant(++tracker.recursion > 0);
}
}
void OperationShardingState::unsetShardRoleForLegacyDDLOperationsSentWithShardVersionIfNeeded(
OperationContext* opCtx, const NamespaceString& nss) {
auto& oss = OperationShardingState::get(opCtx);
auto it = oss._shardVersions.find(nss.ns());
if (it != oss._shardVersions.end()) {
auto& tracker = it->second;
tassert(6848500,
"DDL operation should not recursively use the shard role",
--tracker.recursion == 0);
if (tracker.recursion == 0)
oss._shardVersions.erase(it);
}
return;
}
boost::optional<ShardVersion> OperationShardingState::getShardVersion(const NamespaceString& nss) {
const auto it = _shardVersions.find(nss.ns());
if (it != _shardVersions.end()) {
return it->second.v;
}
return boost::none;
}
boost::optional<DatabaseVersion> OperationShardingState::getDbVersion(StringData dbName) const {
const auto it = _databaseVersions.find(dbName);
if (it != _databaseVersions.end()) {
return it->second.v;
}
return boost::none;
}
Status OperationShardingState::waitForCriticalSectionToComplete(
OperationContext* opCtx, SharedSemiFuture<void> critSecSignal) noexcept {
// Must not block while holding a lock
invariant(!opCtx->lockState()->isLocked());
// If we are in a transaction, limit the time we can wait behind the critical section. This is
// needed in order to prevent distributed deadlocks in situations where a DDL operation needs to
// acquire the critical section on several shards.
//
// In such cases, shard running a transaction could be waiting for the critical section to be
// exited, while on another shard the transaction has already executed some statement and
// stashed locks which prevent the critical section from being acquired in that node. Limiting
// the wait behind the critical section will ensure that the transaction will eventually get
// aborted.
if (opCtx->inMultiDocumentTransaction()) {
try {
opCtx->runWithDeadline(
opCtx->getServiceContext()->getFastClockSource()->now() +
Milliseconds(metadataRefreshInTransactionMaxWaitBehindCritSecMS.load()),
ErrorCodes::ExceededTimeLimit,
[&] { critSecSignal.wait(opCtx); });
return Status::OK();
} catch (const DBException& ex) {
// This is a best-effort attempt to wait for the critical section to complete, so no
// need to handle any exceptions
return ex.toStatus();
}
} else {
return critSecSignal.waitNoThrow(opCtx);
}
}
void OperationShardingState::setShardingOperationFailedStatus(const Status& status) {
invariant(!_shardingOperationFailedStatus);
_shardingOperationFailedStatus = std::move(status);
}
boost::optional<Status> OperationShardingState::resetShardingOperationFailedStatus() {
if (!_shardingOperationFailedStatus) {
return boost::none;
}
Status failedStatus = Status(*_shardingOperationFailedStatus);
_shardingOperationFailedStatus = boost::none;
return failedStatus;
}
using ScopedAllowImplicitCollectionCreate_UNSAFE =
OperationShardingState::ScopedAllowImplicitCollectionCreate_UNSAFE;
ScopedAllowImplicitCollectionCreate_UNSAFE::ScopedAllowImplicitCollectionCreate_UNSAFE(
OperationContext* opCtx)
: _opCtx(opCtx) {
auto& oss = get(_opCtx);
invariant(!oss._allowCollectionCreation);
oss._allowCollectionCreation = true;
}
ScopedAllowImplicitCollectionCreate_UNSAFE::~ScopedAllowImplicitCollectionCreate_UNSAFE() {
auto& oss = get(_opCtx);
invariant(oss._allowCollectionCreation);
oss._allowCollectionCreation = false;
}
ScopedSetShardRole::ScopedSetShardRole(OperationContext* opCtx,
NamespaceString nss,
boost::optional<ShardVersion> shardVersion,
boost::optional<DatabaseVersion> databaseVersion)
: _opCtx(opCtx),
_nss(std::move(nss)),
_shardVersion(std::move(shardVersion)),
_databaseVersion(std::move(databaseVersion)) {
// "Fixed" dbVersions are only used for dbs that don't have the sharding infrastructure set up
// to handle real database or shard versions (like config and admin), so we ignore them.
if (_databaseVersion && _databaseVersion->isFixed()) {
uassert(7331300,
"A 'fixed' dbVersion should only be used with an unsharded shard version or none "
"at all",
!_shardVersion || _shardVersion == ShardVersion::UNSHARDED());
_databaseVersion.reset();
_shardVersion.reset();
}
OperationShardingState::setShardRole(_opCtx, _nss, _shardVersion, _databaseVersion);
}
ScopedSetShardRole::~ScopedSetShardRole() {
auto& oss = OperationShardingState::get(_opCtx);
if (_shardVersion) {
auto it = oss._shardVersions.find(_nss.ns());
invariant(it != oss._shardVersions.end());
auto& tracker = it->second;
invariant(--tracker.recursion >= 0);
if (tracker.recursion == 0)
oss._shardVersions.erase(it);
}
if (_databaseVersion) {
auto it = oss._databaseVersions.find(_nss.db());
invariant(it != oss._databaseVersions.end());
auto& tracker = it->second;
invariant(--tracker.recursion >= 0);
if (tracker.recursion == 0)
oss._databaseVersions.erase(it);
}
}
} // namespace mongo
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