mongo::ShardingState Class Reference

#include <d_logic.h>

Public Member Functions
void	appendInfo (BSONObjBuilder &b)
void	donateChunk (const string &ns, const BSONObj &min, const BSONObj &max, ShardChunkVersion version)
void	enable (const string &server)
bool	enabled () const
const string &	getConfigServer () const
ShardChunkManagerPtr	getShardChunkManager (const string &ns)
const ConfigVersion	getVersion (const string &ns) const
void	gotShardHost (string host)
void	gotShardName (const string &name)
bool	hasVersion (const string &ns, ConfigVersion &version)
bool	hasVersion (const string &ns)
bool	inCriticalMigrateSection ()
bool	needShardChunkManager (const string &ns) const
void	resetShardingState ()
void	resetVersion (const string &ns)
	ShardingState ()
void	splitChunk (const string &ns, const BSONObj &min, const BSONObj &max, const vector< BSONObj > &splitKeys, ShardChunkVersion version)
bool	trySetVersion (const string &ns, ConfigVersion &version)
void	undoDonateChunk (const string &ns, const BSONObj &min, const BSONObj &max, ShardChunkVersion version)
Private Types
typedef map< string, ShardChunkManagerPtr >	ChunkManagersMap
Private Attributes
ChunkManagersMap	_chunks
string	_configServer
bool	_enabled
mongo::mutex	_mutex
string	_shardHost
string	_shardName

Detailed Description

Definition at line 38 of file d_logic.h.

Member Typedef Documentation

typedef map<string,ShardChunkManagerPtr> mongo::ShardingState::ChunkManagersMap [private]

Definition at line 151 of file d_logic.h.

Constructor & Destructor Documentation

mongo::ShardingState::ShardingState ( )

Member Function Documentation

void mongo::ShardingState::appendInfo ( BSONObjBuilder & b )

void mongo::ShardingState::donateChunk	(	const string &	ns,
		const BSONObj &	min,
		const BSONObj &	max,
		ShardChunkVersion	version
	)

Creates and installs a new chunk manager for a given collection by "forgetting" about one of its chunks. The new manager uses the provided version, which has to be higher than the current manager's. One exception: if the forgotten chunk is the last one in this shard for the collection, version has to be 0.

If it runs successfully, clients need to grab the new version to access the collection.

Parameters:

	ns	the collection
	min	max the chunk to eliminate from the current manager
	version	at which the new manager should be at

void mongo::ShardingState::enable ( const string & server )

bool mongo::ShardingState::enabled ( ) const [inline]

Definition at line 42 of file d_logic.h.

const string& mongo::ShardingState::getConfigServer ( ) const [inline]

Definition at line 43 of file d_logic.h.

ShardChunkManagerPtr mongo::ShardingState::getShardChunkManager ( const string & ns )

const ConfigVersion mongo::ShardingState::getVersion ( const string & ns ) const

void mongo::ShardingState::gotShardHost ( string host )

void mongo::ShardingState::gotShardName ( const string & name )

bool mongo::ShardingState::hasVersion	(	const string &	ns,
		ConfigVersion &	version
	)

bool mongo::ShardingState::hasVersion ( const string & ns )

bool mongo::ShardingState::inCriticalMigrateSection ( )

bool mongo::ShardingState::needShardChunkManager ( const string & ns ) const

void mongo::ShardingState::resetShardingState ( )

Reverts back to a state where this mongod is not sharded.

void mongo::ShardingState::resetVersion ( const string & ns )

Uninstalls the manager for a given collection. This should be used when the collection is dropped.

NOTE: An existing collection with no chunks on this shard will have a manager on version 0, which is different than a a dropped collection, which will not have a manager.

TODO When sharding state is enabled, absolutely all collections should have a manager. (The non-sharded ones are a be degenerate case of one-chunk collections). For now, a dropped collection and an non-sharded one are indistinguishable (SERVER-1849)

Parameters:

ns

the collection to be dropped

void mongo::ShardingState::splitChunk	(	const string &	ns,
		const BSONObj &	min,
		const BSONObj &	max,
		const vector< BSONObj > &	splitKeys,
		ShardChunkVersion	version
	)

Creates and installs a new chunk manager for a given collection by splitting one of its chunks in two or more. The version for the first split chunk should be provided. The subsequent chunks' version would be the latter with the minor portion incremented.

The effect on clients will depend on the version used. If the major portion is the same as the current shards, clients shouldn't perceive the split.

Parameters:

	ns	the collection
	min	max the chunk that should be split
	splitKeys	point in which to split
	version	at which the new manager should be at

bool mongo::ShardingState::trySetVersion	(	const string &	ns,
		ConfigVersion &	version
	)

Requests to access a collection at a certain version. If the collection's manager is not at that version it will try to update itself to the newest version. The request is only granted if the version is the current or the newest one.

Parameters:

	ns	collection to be accessed
	version	(IN) the client belive this collection is on and (OUT) the version the manager is actually in

Returns:: true if the access can be allowed at the provided version

void mongo::ShardingState::undoDonateChunk	(	const string &	ns,
		const BSONObj &	min,
		const BSONObj &	max,
		ShardChunkVersion	version
	)

Creates and installs a new chunk manager for a given collection by reclaiming a previously donated chunk. The previous manager's version has to be provided.

If it runs successfully, clients that became stale by the previous donateChunk will be able to access the collection again.

Parameters: