/**
* 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 .
*
* 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.
*/
#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kSharding
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/operation_context.h"
#include "mongo/db/repl/repl_client_info.h"
#include "mongo/db/s/config/sharding_catalog_manager.h"
#include "mongo/s/catalog/dist_lock_manager.h"
#include "mongo/s/catalog/type_database.h"
#include "mongo/s/catalog_cache.h"
#include "mongo/s/grid.h"
#include "mongo/util/log.h"
#include "mongo/util/scopeguard.h"
namespace mongo {
namespace {
/**
* Internal sharding command run on config servers to drop a database.
*/
class ConfigSvrDropDatabaseCommand : public BasicCommand {
public:
ConfigSvrDropDatabaseCommand() : BasicCommand("_configsvrDropDatabase") {}
AllowedOnSecondary secondaryAllowed(ServiceContext*) const override {
return AllowedOnSecondary::kNever;
}
bool adminOnly() const override {
return true;
}
bool supportsWriteConcern(const BSONObj& cmd) const override {
return true;
}
std::string help() const override {
return "Internal command, which is exported by the sharding config server. Do not call "
"directly. Drops a database.";
}
Status checkAuthForCommand(Client* client,
const std::string& dbname,
const BSONObj& cmdObj) const override {
if (!AuthorizationSession::get(client)->isAuthorizedForActionsOnResource(
ResourcePattern::forClusterResource(), ActionType::internal)) {
return Status(ErrorCodes::Unauthorized, "Unauthorized");
}
return Status::OK();
}
std::string parseNs(const std::string& dbname, const BSONObj& cmdObj) const {
return cmdObj.firstElement().str();
}
bool run(OperationContext* opCtx,
const std::string& dbname_unused,
const BSONObj& cmdObj,
BSONObjBuilder& result) {
uassert(ErrorCodes::IllegalOperation,
"_configsvrDropDatabase can only be run on config servers",
serverGlobalParams.clusterRole == ClusterRole::ConfigServer);
// Set the operation context read concern level to local for reads into the config database.
repl::ReadConcernArgs::get(opCtx) =
repl::ReadConcernArgs(repl::ReadConcernLevel::kLocalReadConcern);
const std::string dbname = parseNs("", cmdObj);
uassert(
ErrorCodes::InvalidNamespace,
str::stream() << "invalid db name specified: " << dbname,
NamespaceString::validDBName(dbname, NamespaceString::DollarInDbNameBehavior::Allow));
uassert(ErrorCodes::InvalidOptions,
str::stream() << "dropDatabase must be called with majority writeConcern, got "
<< cmdObj,
opCtx->getWriteConcern().wMode == WriteConcernOptions::kMajority);
auto const catalogClient = Grid::get(opCtx)->catalogClient();
auto const catalogManager = ShardingCatalogManager::get(opCtx);
auto scopedLock =
ShardingCatalogManager::get(opCtx)->serializeCreateOrDropDatabase(opCtx, dbname);
auto dbDistLock = uassertStatusOK(catalogClient->getDistLockManager()->lock(
opCtx, dbname, "dropDatabase", DistLockManager::kDefaultLockTimeout));
// Invalidate the database metadata so the next access kicks off a full reload.
ON_BLOCK_EXIT([opCtx, dbname] { Grid::get(opCtx)->catalogCache()->purgeDatabase(dbname); });
auto dbInfo =
catalogClient->getDatabase(opCtx, dbname, repl::ReadConcernArgs::get(opCtx).getLevel());
// If the namespace isn't found, treat the drop as a success. In case the drop just happened
// and has not fully propagated, set the client's last optime to the system's last optime to
// ensure the client waits.
if (dbInfo.getStatus() == ErrorCodes::NamespaceNotFound) {
result.append("info", "database does not exist");
repl::ReplClientInfo::forClient(opCtx->getClient()).setLastOpToSystemLastOpTime(opCtx);
return true;
}
// If we didn't get a NamespaceNotFound error, make sure there wasn't some other type of
// error.
auto dbType = uassertStatusOK(dbInfo).value;
uassertStatusOK(
catalogClient->logChangeChecked(opCtx,
"dropDatabase.start",
dbname,
BSONObj(),
ShardingCatalogClient::kMajorityWriteConcern));
// Drop the database's collections.
for (const auto& nss : catalogClient->getAllShardedCollectionsForDb(
opCtx, dbname, repl::ReadConcernArgs::get(opCtx).getLevel())) {
auto collDistLock = uassertStatusOK(catalogClient->getDistLockManager()->lock(
opCtx, nss.ns(), "dropCollection", DistLockManager::kDefaultLockTimeout));
uassertStatusOK(catalogManager->dropCollection(opCtx, nss));
}
// Drop the database from the primary shard first.
_dropDatabaseFromShard(opCtx, dbType.getPrimary(), dbname);
// Drop the database from each of the remaining shards.
{
std::vector allShardIds;
Grid::get(opCtx)->shardRegistry()->getAllShardIdsNoReload(&allShardIds);
for (const ShardId& shardId : allShardIds) {
_dropDatabaseFromShard(opCtx, shardId, dbname);
}
}
// Remove the database entry from the metadata.
const Status status =
catalogClient->removeConfigDocuments(opCtx,
DatabaseType::ConfigNS,
BSON(DatabaseType::name(dbname)),
ShardingCatalogClient::kMajorityWriteConcern);
uassertStatusOKWithContext(
status, str::stream() << "Could not remove database '" << dbname << "' from metadata");
catalogClient->logChange(
opCtx, "dropDatabase", dbname, BSONObj(), ShardingCatalogClient::kMajorityWriteConcern);
result.append("dropped", dbname);
return true;
}
private:
/**
* Sends the 'dropDatabase' command for the specified database to the specified shard. Throws
* DBException on failure.
*/
static void _dropDatabaseFromShard(OperationContext* opCtx,
const ShardId& shardId,
const std::string& dbName) {
const auto dropDatabaseCommandBSON = [opCtx] {
BSONObjBuilder builder;
builder.append("dropDatabase", 1);
builder.append(WriteConcernOptions::kWriteConcernField,
opCtx->getWriteConcern().toBSON());
return builder.obj();
}();
const auto shard =
uassertStatusOK(Grid::get(opCtx)->shardRegistry()->getShard(opCtx, shardId));
auto cmdDropDatabaseResult = uassertStatusOK(shard->runCommandWithFixedRetryAttempts(
opCtx,
ReadPreferenceSetting{ReadPreference::PrimaryOnly},
dbName,
dropDatabaseCommandBSON,
Shard::RetryPolicy::kIdempotent));
uassertStatusOK(cmdDropDatabaseResult.commandStatus);
uassertStatusOK(cmdDropDatabaseResult.writeConcernStatus);
};
} configsvrDropDatabaseCmd;
} // namespace
} // namespace mongo