Establishes and maintains a set of TCP connections. More...

#include <ConnectionManager.h>

Inheritance diagram for Hypertable::ConnectionManager:

Collaboration diagram for Hypertable::ConnectionManager:

Classes
class	ConnectionState
	Per-connection state. More...

struct	LtConnectionState
	StringWeakOrdering for connection retry heap. More...

class	SharedImpl
	Connection manager state shared between Connection manager objects. More...

Public Member Functions
	ConnectionManager (Comm *comm=0)
	Constructor. More...

	ConnectionManager (const ConnectionManager &cm)=delete

virtual	~ConnectionManager ()
	Destructor. More...

void	add (const CommAddress &addr, uint32_t timeout_ms, const char *service_name)
	Adds a connection. More...

void	add (const CommAddress &addr, uint32_t timeout_ms, const char *service_name, DispatchHandlerPtr &handler)
	Adds a connection with a dispatch handler. More...

void	add_with_initializer (const CommAddress &addr, uint32_t timeout_ms, const char *service_name, DispatchHandlerPtr &handler, ConnectionInitializerPtr &initializer)
	Adds a connection with a dispatch handler and connection initializer. More...

void	add (const CommAddress &addr, const CommAddress &local_addr, uint32_t timeout_ms, const char *service_name)
	Adds a connection bound to a local address. More...

void	add (const CommAddress &addr, const CommAddress &local_addr, uint32_t timeout_ms, const char *service_name, DispatchHandlerPtr &handler)
	Adds a connection with a dispatch handler bound to a local address. More...

int	remove (const CommAddress &addr)
	Removes a connection from the connection manager. More...

bool	wait_for_connection (const CommAddress &addr, uint32_t max_wait_ms)
	Blocks until the connection to the given address is established. More...

bool	wait_for_connection (const CommAddress &addr, Timer &timer)
	Blocks until the connection to the given address is established. More...

Comm *	get_comm ()
	Returns the Comm object associated with this connection manager. More...

void	set_quiet_mode (bool mode)
	Sets the SharedImpl::quiet_mode flag which will disable the generation of log messages upon failed connection attempts. More...

virtual void	handle (EventPtr &event)
	Primary dispatch handler method. More...

void	connect_retry_loop ()
	Connect retry loop. More...

Public Member Functions inherited from Hypertable::DispatchHandler
virtual	~DispatchHandler ()
	Destructor. More...

Private Types
enum	State { State::DISCONNECTED = 0, State::CONNECTED, State::READY, State::DECOMMISSIONED }

typedef std::shared_ptr < ConnectionState >	ConnectionStatePtr
	Smart pointer to ConnectionState. More...

typedef std::shared_ptr < SharedImpl >	SharedImplPtr
	Smart pointer to SharedImpl object. More...

Private Member Functions
void	add_internal (const CommAddress &addr, const CommAddress &local_addr, uint32_t timeout_ms, const char *service_name, DispatchHandlerPtr &handler, ConnectionInitializerPtr &initializer)
	Called by the add methods to add a connection. More...

bool	wait_for_connection (ConnectionStatePtr &conn_state, Timer &timer)
	This method blocks until the connection represented by `conn_state` is established. More...

void	send_connect_request (ConnectionStatePtr &conn_state)
	Calls Comm::connect to establish a connection. More...

void	send_initialization_request (ConnectionStatePtr &conn_state)
	Sends an initialization request. More...

void	schedule_retry (ConnectionStatePtr &conn_state, const std::string &message)
	Schedules a connection retry attempt. More...

Private Attributes
SharedImplPtr	m_impl
	Smart pointer to connection manager state. More...

Detailed Description

Establishes and maintains a set of TCP connections.

If any of the connections gets broken, then this class will continuously attempt to re-establish the connection, pausing for a while in between attempts.

Definition at line 60 of file ConnectionManager.h.

Member Typedef Documentation

typedef std::shared_ptr<ConnectionState> Hypertable::ConnectionManager::ConnectionStatePtr

private

Smart pointer to ConnectionState.

Definition at line 97 of file ConnectionManager.h.

typedef std::shared_ptr<SharedImpl> Hypertable::ConnectionManager::SharedImplPtr

private

Smart pointer to SharedImpl object.

Definition at line 144 of file ConnectionManager.h.

Constructor & Destructor Documentation

Hypertable::ConnectionManager::ConnectionManager ( Comm * comm = 0 )

inline

Constructor.

Creates a thread to do connection retry attempts.

Parameters

comm	Pointer to the comm object

Definition at line 153 of file ConnectionManager.h.

Hypertable::ConnectionManager::ConnectionManager ( const ConnectionManager & cm )

delete

virtual Hypertable::ConnectionManager::~ConnectionManager ( )

inlinevirtual

Destructor.

Definition at line 164 of file ConnectionManager.h.

Member Function Documentation

void ConnectionManager::add	(	const CommAddress &	addr,
		uint32_t	timeout_ms,
		const char *	service_name
	)

Adds a connection.

The addr parameter holds the address to which the connection manager should maintain a connection. This method first checks to see if the address is already registered with the connection manager and returns immediately if it is. Otherwise, it adds the address to an internal connection map, attempts to establish a connection to the address, and then returns. Once a connection has been added, the internal manager thread will maintian the connection by continually re-establishing the connection if it ever gets broken.

Parameters

addr	The address to maintain a connection to
timeout_ms	When connection dies, wait this many milliseconds before attempting to reestablish
service_name	The name of the serivce at the other end of the connection used for descriptive log messages

Definition at line 74 of file ConnectionManager.cc.

void ConnectionManager::add	(	const CommAddress &	addr,
		uint32_t	timeout_ms,
		const char *	service_name,
		DispatchHandlerPtr &	handler
	)

Adds a connection with a dispatch handler.

The addr parameter holds the address to which connection manager should maintain a connection. This method first checks to see if the address is already registered with the connection manager and returns immediately if it is. Otherwise, it adds the address to an internal connection map, attempts to establish a connection to the address, and then returns. Once a connection has been added, the internal manager thread will maintian the connection by continually re-establishing the connection if it ever gets broken.

This version of add accepts a DispatchHandler argument, handler, which is registered as the connection handler for the connection and receives all events that occur on the connection (except for the initialization handshake messages).

Parameters

addr	The address to maintain a connection to
timeout_ms	The timeout value (in milliseconds) that gets passed into Comm::connect and also used as the waiting period betweeen connection attempts
service_name	The name of the serivce at the other end of the connection used for descriptive log messages
handler	This is the default handler to install on the connection. All events get changed through to this handler.

Definition at line 58 of file ConnectionManager.cc.

void ConnectionManager::add	(	const CommAddress &	addr,
		const CommAddress &	local_addr,
		uint32_t	timeout_ms,
		const char *	service_name
	)

Adds a connection bound to a local address.

The addr holds the address to which the connection manager should maintain a connection. This method first checks to see if the address is already registered with the connection manager and returns immediately if it is. Otherwise, it adds the address to an internal connection map, attempts to establish a connection to the address, and then returns. From here on out, the internal manager thread will maintian the connection by continually re-establishing the connection if it ever gets broken.

Parameters

addr	The address to maintain a connection to
local_addr	The local address to bind to
timeout_ms	When connection dies, wait this many milliseconds before attempting to reestablish
service_name	The name of the serivce at the other end of the connection used for descriptive log messages

Definition at line 91 of file ConnectionManager.cc.

void ConnectionManager::add	(	const CommAddress &	addr,
		const CommAddress &	local_addr,
		uint32_t	timeout_ms,
		const char *	service_name,
		DispatchHandlerPtr &	handler
	)

Adds a connection with a dispatch handler bound to a local address.

The addr holds the address to which the connection manager should maintain a connection. This method first checks to see if the address is already registered with the connection manager and returns immediately if it is. Otherwise, it adds the address to an internal connection map, attempts to establish a connection to the address, and then returns. From here on out, the internal manager thread will maintian the connection by continually re-establishing the connection if it ever gets broken.

Parameters

addr	The address to maintain a connection to
local_addr	The local address to bind to
timeout_ms	The timeout value (in milliseconds) that gets passed into Comm::connect and also used as the waiting period betweeen connection attempts
service_name	The name of the serivce at the other end of the connection used for descriptive log messages
handler	This is the default handler to install on the connection. All events get changed through to this handler.

Definition at line 82 of file ConnectionManager.cc.

void ConnectionManager::add_internal	(	const CommAddress &	addr,
		const CommAddress &	local_addr,
		uint32_t	timeout_ms,
		const char *	service_name,
		DispatchHandlerPtr &	handler,
		ConnectionInitializerPtr &	initializer
	)

private

Called by the add methods to add a connection.

This method creates and initializes a ConnectionState object for the connnection, adds it to either SharedImpl::conn_map or SharedImpl::conn_map_proxy depending on the type of address, and then issues a connect request.

Parameters

addr	The address to maintain a connection to
local_addr	The local address to bind to
timeout_ms	The timeout value (in milliseconds) that gets passed into Comm::connect and also used as the waiting period betweeen connection attempts
service_name	The name of the serivce at the other end of the connection used for descriptive log messages
handler	This is the default handler to install on the connection. All events get changed through to this handler.
initializer	Connection initialization handshake driver

Start retry thread

Definition at line 98 of file ConnectionManager.cc.

void ConnectionManager::add_with_initializer	(	const CommAddress &	addr,
		uint32_t	timeout_ms,
		const char *	service_name,
		DispatchHandlerPtr &	handler,
		ConnectionInitializerPtr &	initializer
	)

Adds a connection with a dispatch handler and connection initializer.

The addr parameter holds the address to which connection manager should maintain a connection. This method first checks to see if the address is already registered with the connection manager and returns immediately if it is. Otherwise, it adds the address to an internal connection map, attempts to establish a connection to the address, and then returns. Once a connection has been added, the internal manager thread will maintian the connection by continually re-establishing the connection if it ever gets broken.

This version of add accepts a connection initializer, initializer, which is used to carry out an initialization handshake. Once the connection has been established, the connection initializer is used to generate an initialization handshake message which is sent to the other end of the connection. and process the response t

Parameters

addr	Address to maintain a connection to
timeout_ms	Timeout value (in milliseconds) that gets passed into Comm::connect and also used as the waiting period between connection attempts
service_name	Name of the serivce at the other end of the connection used for descriptive log messages
handler	Default dispatch handler for connection.
initializer	Connection initialization handshake driver

Definition at line 65 of file ConnectionManager.cc.

void ConnectionManager::connect_retry_loop ( )

Connect retry loop.

This is the boost::thread run method.

This method is called as the retry thread function.

Definition at line 460 of file ConnectionManager.cc.

Comm* Hypertable::ConnectionManager::get_comm ( )

inline

Returns the Comm object associated with this connection manager.

Returns: the assocated comm object

Definition at line 321 of file ConnectionManager.h.

void ConnectionManager::handle ( EventPtr & event )

virtual

Primary dispatch handler method.

This is the AsyncComm dispatch handler method.

The ConnectionManager is a dispatch handler and is registered as the handler for all of the connections that it manages. This method does the job of maintianing connections. This method will forward all events (except initialization handshake messages) to any dispatch handler registered for the connection on which the event was generated.

Parameters

event Comm layer event

It gets called for each connection related event (establishment, disconnect, etc.) for each connection. For connect events, the connection's connected flag is set to true and it's condition variable is signaled. For all other events (e.g. disconnect or error), the connection's connected flag is set to false and a retry is scheduled.

Parameters

event shared pointer to event object

register address

Implements Hypertable::DispatchHandler.

Definition at line 334 of file ConnectionManager.cc.

int ConnectionManager::remove ( const CommAddress & addr )

Removes a connection from the connection manager.

Parameters

addr	remote address of connection to remove

Returns: Error code (Error::OK on success)

Definition at line 265 of file ConnectionManager.cc.

void ConnectionManager::schedule_retry	(	ConnectionStatePtr &	conn_state,
		const std::string &	message
	)

private

Schedules a connection retry attempt.

Sets conn_state to disconnected and schedules another connection attempt in the future.

Parameters

conn_state	Pointer to connection state object representing connection
message	Message indicating why retry is being attempted

Definition at line 437 of file ConnectionManager.cc.

void ConnectionManager::send_connect_request ( ConnectionStatePtr & conn_state )

private

Calls Comm::connect to establish a connection.

Attempts to establish a connection for the given ConnectionState object.

If the connection attempt results in an error, an error message is logged indicating that the connection attempt to the given service failed, and another connection attempt is scheduled for ConnectionState::timeout_ms in the future.

Parameters

conn_state Pointer to connection state object representing connection

If a failure occurs, it prints an error message and then schedules a retry by updating the next_retry member of the conn_state object and pushing it onto the retry heap

Parameters

conn_state The connection state record

Definition at line 209 of file ConnectionManager.cc.

void ConnectionManager::send_initialization_request ( ConnectionStatePtr & conn_state )

private

Sends an initialization request.

Parameters

conn_state Pointer to connection state object representing connection

Definition at line 420 of file ConnectionManager.cc.

void Hypertable::ConnectionManager::set_quiet_mode ( bool mode )

inline

Sets the SharedImpl::quiet_mode flag which will disable the generation of log messages upon failed connection attempts.

It is set to false by default.

Parameters

mode	The new value for the SharedImpl::quiet_mode flag

Definition at line 329 of file ConnectionManager.h.

bool ConnectionManager::wait_for_connection	(	const CommAddress &	addr,
		uint32_t	max_wait_ms
	)

Blocks until the connection to the given address is established.

The given address must have been previously added with a call to Add. If the connection is not established within max_wait_ms, then the method returns false.

Parameters

addr	the address of the connection to wait for
max_wait_ms	The maximum time to wait for the connection before returning

Returns: true if connected, false otherwise

Definition at line 145 of file ConnectionManager.cc.

bool ConnectionManager::wait_for_connection	(	const CommAddress &	addr,
		Timer &	timer
	)

Blocks until the connection to the given address is established.

The given address must have been previously added with a call to Add. If the connection is not established before the timer expires, then the method returns false.

Parameters

addr	the address of the connection to wait for
timer	running timer object

Returns: true if connected, false otherwise

Definition at line 153 of file ConnectionManager.cc.

bool ConnectionManager::wait_for_connection	(	ConnectionStatePtr &	conn_state,
		Timer &	timer
	)

private

This method blocks until the connection represented by conn_state is established.

If the connection is not established before timer expires, then the method returns false.

Parameters

conn_state	Pointer to connection state object representing connection
timer	Maximum wait timer

Returns: true if connected, false if timer expired before connection was established.

Definition at line 178 of file ConnectionManager.cc.

Member Data Documentation

SharedImplPtr Hypertable::ConnectionManager::m_impl

private

Smart pointer to connection manager state.

Definition at line 406 of file ConnectionManager.h.

The documentation for this class was generated from the following files:

/home/doug/src/hypertable/src/cc/AsyncComm/ConnectionManager.h
/home/doug/src/hypertable/src/cc/AsyncComm/ConnectionManager.cc

Classes

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation