/**
* Copyright (C) 2008-2015 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see .
*
* 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
#include "mongo/db/jsobj.h"
#include "mongo/db/repl/optime.h"
#include "mongo/platform/atomic_word.h"
#include "mongo/s/client/shard.h"
#include "mongo/util/concurrency/mutex.h"
namespace mongo {
class ChunkManager;
class CollectionType;
class DatabaseType;
class DBConfig;
class OperationContext;
struct CollectionInfo {
CollectionInfo() {
_dirty = false;
_dropped = false;
}
CollectionInfo(OperationContext* txn, const CollectionType& in, repl::OpTime);
~CollectionInfo();
bool isSharded() const {
return _cm.get();
}
std::shared_ptr getCM() const {
return _cm;
}
void resetCM(ChunkManager* cm);
void unshard();
bool isDirty() const {
return _dirty;
}
bool wasDropped() const {
return _dropped;
}
void save(OperationContext* txn, const std::string& ns);
void useChunkManager(std::shared_ptr manager);
bool unique() const {
return _unique;
}
BSONObj key() const {
return _key;
}
repl::OpTime getConfigOpTime() const {
return _configOpTime;
}
private:
BSONObj _key;
bool _unique;
std::shared_ptr _cm;
bool _dirty;
bool _dropped;
repl::OpTime _configOpTime;
};
/**
* top level configuration for a database
*/
class DBConfig {
public:
DBConfig(std::string name, const DatabaseType& dbt, repl::OpTime configOpTime);
~DBConfig();
/**
* The name of the database which this entry caches.
*/
const std::string& name() const {
return _name;
}
/**
* Whether sharding is enabled for this database.
*/
bool isShardingEnabled();
ShardId getPrimaryId();
/**
* Removes all cached metadata for the specified namespace so that subsequent attempts to
* retrieve it will cause a full reload.
*/
void invalidateNs(const std::string& ns);
void enableSharding(OperationContext* txn);
/**
@return true if there was sharding info to remove
*/
bool removeSharding(OperationContext* txn, const std::string& ns);
/**
* @return whether or not the 'ns' collection is partitioned
*/
bool isSharded(const std::string& ns);
// Atomically returns *either* the chunk manager *or* the primary shard for the collection,
// neither if the collection doesn't exist.
void getChunkManagerOrPrimary(OperationContext* txn,
const std::string& ns,
std::shared_ptr& manager,
std::shared_ptr& primary);
std::shared_ptr getChunkManager(OperationContext* txn,
const std::string& ns,
bool reload = false,
bool forceReload = false);
std::shared_ptr getChunkManagerIfExists(OperationContext* txn,
const std::string& ns,
bool reload = false,
bool forceReload = false);
void setPrimary(OperationContext* txn, const ShardId& newPrimaryId);
/**
* Returns true if it is successful at loading the DBConfig, false if the database is not found,
* and throws on all other errors.
*/
bool load(OperationContext* txn);
bool reload(OperationContext* txn);
bool dropDatabase(OperationContext*, std::string& errmsg);
void getAllShardIds(std::set* shardIds);
void getAllShardedCollections(std::set& namespaces);
protected:
typedef std::map CollectionInfoMap;
typedef AtomicUInt64::WordType Counter;
bool _dropShardedCollections(OperationContext* txn,
int& num,
std::set& shardIds,
std::string& errmsg);
/**
* Returns true if it is successful at loading the DBConfig, false if the database is not found,
* and throws on all other errors.
* Also returns true without reloading if reloadIteration is not equal to the _reloadCount.
* This is to avoid multiple threads attempting to reload do duplicate work.
*/
bool _loadIfNeeded(OperationContext* txn, Counter reloadIteration);
void _save(OperationContext* txn, bool db = true, bool coll = true);
// All member variables are labeled with one of the following codes indicating the
// synchronization rules for accessing them.
//
// (L) Must hold _lock for access.
// (I) Immutable, can access freely.
// (S) Self synchronizing, no explicit locking needed.
//
// Mutex lock order:
// _hitConfigServerLock -> _lock
//
// Name of the database which this entry caches
const std::string _name; // (I)
// Primary shard id
ShardId _primaryId; // (L)
// Whether sharding has been enabled for this database
bool _shardingEnabled; // (L)
// Set of collections and lock to protect access
stdx::mutex _lock;
CollectionInfoMap _collections; // (L)
// OpTime of config server when the database definition was loaded.
repl::OpTime _configOpTime; // (L)
// Ensures that only one thread at a time loads collection configuration data from
// the config server
stdx::mutex _hitConfigServerLock;
// Increments every time this performs a full reload. Since a full reload can take a very
// long time for very large clusters, this can be used to minimize duplicate work when multiple
// threads tries to perform full rerload at roughly the same time.
AtomicUInt64 _reloadCount; // (S)
};
class ConfigServer {
public:
/**
* For use in mongos and mongod which needs notifications about changes to shard and config
* server replset membership to update the ShardRegistry.
*
* This is expected to be run in an existing thread.
*/
static void replicaSetChangeShardRegistryUpdateHook(const std::string& setName,
const std::string& newConnectionString);
/**
* For use in mongos which needs notifications about changes to shard replset membership to
* update the config.shards collection.
*
* This is expected to be run in a brand new thread.
*/
static void replicaSetChangeConfigServerUpdateHook(const std::string& setName,
const std::string& newConnectionString);
};
} // namespace mongo