Sends LoggingEvent objects to a remote a log server, usually Apache Chainsaw. More...

Inheritance diagram for SocketAppender:

Public Member Functions
	SocketAppender ()

	~SocketAppender ()

	SocketAppender (helpers::InetAddressPtr &address, int port)
	Connects to remote server at `address` and `port`. More...

	SocketAppender (const LogString &host, int port)
	Connects to remote server at `host` and `port`. More...

Public Member Functions inherited from SocketAppenderSkeleton
	SocketAppenderSkeleton (int defaultPort, int reconnectionDelay)

	~SocketAppenderSkeleton ()

	SocketAppenderSkeleton (helpers::InetAddressPtr address, int port, int reconnectionDelay)
	Connects to remote server at `address` and `port`. More...

	SocketAppenderSkeleton (const LogString &host, int port, int reconnectionDelay)
	Connects to remote server at `host` and `port`. More...

void	activateOptions (log4cxx::helpers::Pool &p)
	Connect to the specified RemoteHost and Port. More...

void	close ()
	Release any resources allocated within the appender such as file handles, network connections, etc. More...

bool	requiresLayout () const
	This appender does not use a layout. More...

void	setRemoteHost (const LogString &host)
	The RemoteHost option takes a string value which should be the host name of the server where a Apache Chainsaw or compatible is running. More...

const LogString &	getRemoteHost () const
	Returns value of the RemoteHost option. More...

void	setPort (int port1)
	The Port option takes a positive integer representing the port where the server is waiting for connections. More...

int	getPort () const
	Returns value of the Port option. More...

void	setLocationInfo (bool locationInfo1)
	The LocationInfo option takes a boolean value. More...

bool	getLocationInfo () const
	Returns value of the LocationInfo option. More...

void	setReconnectionDelay (int reconnectionDelay1)
	The ReconnectionDelay option takes a positive integer representing the number of milliseconds to wait between each failed connection attempt to the server. More...

int	getReconnectionDelay () const
	Returns value of the ReconnectionDelay option. More...

void	fireConnector ()

void	setOption (const LogString &option, const LogString &value)
	Set `option` to `value`. More...

Public Member Functions inherited from AppenderSkeleton
	AppenderSkeleton ()

	AppenderSkeleton (const LayoutPtr &layout)

void	addRef () const

void	releaseRef () const

void	finalize ()
	Finalize this appender by calling the derived class' `close` method. More...

void	addFilter (const spi::FilterPtr &newFilter)
	Add a filter to end of the filter list. More...

void	clearFilters ()
	Clear the filters chain. More...

const spi::ErrorHandlerPtr &	getErrorHandler () const
	Return the currently set spi::ErrorHandler for this Appender. More...

spi::FilterPtr	getFilter () const
	Returns the head Filter. More...

const spi::FilterPtr &	getFirstFilter () const
	Return the first filter in the filter chain for this Appender. More...

LayoutPtr	getLayout () const
	Returns the layout of this appender. More...

LogString	getName () const
	Returns the name of this Appender. More...

const LevelPtr &	getThreshold () const
	Returns this appenders threshold level. More...

bool	isAsSevereAsThreshold (const LevelPtr &level) const
	Check whether the message level is below the appender's threshold. More...

virtual void	doAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)
	This method performs threshold checks and invokes filters before delegating actual logging to the subclasses specific AppenderSkeleton::append method. More...

void	setErrorHandler (const spi::ErrorHandlerPtr &eh)
	Set the ErrorHandler for this Appender. More...

void	setLayout (const LayoutPtr &layout1)
	Set the layout for this appender. More...

void	setName (const LogString &name1)
	Set the name of this Appender. More...

void	setThreshold (const LevelPtr &threshold)
	Set the threshold level. More...

Public Member Functions inherited from Appender
virtual	~Appender ()

Public Member Functions inherited from OptionHandler
virtual	~OptionHandler ()

Public Member Functions inherited from Object
virtual const helpers::Class &	getClass () const

virtual	~Object ()

virtual bool	instanceof (const Class &clazz) const =0

virtual const void *	cast (const Class &clazz) const =0

Public Member Functions inherited from ObjectImpl
	ObjectImpl ()

virtual	~ObjectImpl ()

void	addRef () const

void	releaseRef () const

Static Public Attributes
static int	DEFAULT_PORT
	The default port number of remote logging server (4560). More...

static int	DEFAULT_RECONNECTION_DELAY
	The default reconnection delay (30000 milliseconds or 30 seconds). More...

Protected Member Functions
virtual void	setSocket (log4cxx::helpers::SocketPtr &socket, log4cxx::helpers::Pool &p)

virtual void	cleanUp (log4cxx::helpers::Pool &p)

virtual int	getDefaultDelay () const

virtual int	getDefaultPort () const

void	append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)
	Subclasses of `AppenderSkeleton` should implement this method to perform actual logging. More...

Protected Member Functions inherited from AppenderSkeleton
void	doAppendImpl (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)

Additional Inherited Members
Static Public Member Functions inherited from Object
static const helpers::Class &	getStaticClass ()

static const log4cxx::helpers::ClassRegistration &	registerClass ()

Protected Attributes inherited from AppenderSkeleton
LayoutPtr	layout
	The layout variable does not need to be set if the appender implementation has its own layout. More...

LogString	name
	Appenders are named. More...

LevelPtr	threshold
	There is no level threshold filtering by default. More...

spi::ErrorHandlerPtr	errorHandler
	It is assumed and enforced that errorHandler is never null. More...

spi::FilterPtr	headFilter
	The first filter in the filter chain. More...

spi::FilterPtr	tailFilter
	The last filter in the filter chain. More...

bool	closed
	Is this appender closed? More...

log4cxx::helpers::Pool	pool

SHARED_MUTEX	mutex

Protected Attributes inherited from ObjectImpl
unsigned int volatile	ref

Detailed Description

Sends LoggingEvent objects to a remote a log server, usually Apache Chainsaw.

The SocketAppender has the following properties:

If sent to Apache Chainsaw, remote logging is non-intrusive as far as the log event is concerned. In other words, the event will be logged with the same time stamp, NDC, location info as if it were logged locally by the client.
SocketAppenders do not use a layout. They ship a serialized LoggingEvent object to the server side.
Remote logging uses the TCP protocol. Consequently, if the server is reachable, then log events will eventually arrive at the server.
If the remote server is down, the logging requests are simply dropped. However, if and when the server comes back up, then event transmission is resumed transparently. This transparent reconneciton is performed by a connector thread which periodically attempts to connect to the server.
Logging events are automatically buffered by the native TCP implementation. This means that if the link to server is slow but still faster than the rate of (log) event production by the client, the client will not be affected by the slow network connection. However, if the network connection is slower then the rate of event production, then the client can only progress at the network rate. In particular, if the network link to the the server is down, the client will be blocked.

On the other hand, if the network link is up, but the server is down, the client will not be blocked when making log requests but the log events will be lost due to server unavailability.
Even if a SocketAppender is no longer attached to any logger, it will not be destroyed in the presence of a connector thread. A connector thread exists only if the connection to the server is down. To avoid this destruction problem, you should close the the SocketAppender explicitly. See also next item.

Long lived applications which create/destroy many SocketAppender instances should be aware of this destruction problem. Most other applications can safely ignore it.
If the application hosting the SocketAppender exits before the SocketAppender is closed either explicitly or subsequent to destruction, then there might be untransmitted data in the pipe which might be lost.

To avoid lost data, it is usually sufficient to close the SocketAppender either explicitly or by calling the LogManager::shutdown method before exiting the application.