Sends spi::LoggingEvent elements to a remote a log server, usually in XML format. More...

#include <xmlsocketappender.h>

Inheritance diagram for log4cxx::net::XMLSocketAppender:

Public Member Functions
	XMLSocketAppender ()

	~XMLSocketAppender ()

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

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

Public Member Functions inherited from log4cxx::net::SocketAppenderSkeleton
	SocketAppenderSkeleton (int defaultPort, int reconnectionDelay)

	~SocketAppenderSkeleton ()

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

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

void	activateOptions (helpers::Pool &p) override
	Activate the options that were previously set with calls to option setters.

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

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

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.

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

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

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

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

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

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.

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

void	fireConnector ()

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

Public Member Functions inherited from log4cxx::AppenderSkeleton
	AppenderSkeleton ()

	AppenderSkeleton (const LayoutPtr &layout)

virtual	~AppenderSkeleton ()

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

void	activateOptions (helpers::Pool &) override
	Activate the options that were previously set with calls to option setters.

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

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

void	clearFilters () override
	Clear the filters chain.

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

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

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

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

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

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

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

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

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

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

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

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

Public Member Functions inherited from log4cxx::Appender
virtual	~Appender ()

virtual void	addFilter (const spi::FilterPtr newFilter)=0
	Add a filter to the end of the filter list.

virtual spi::FilterPtr	getFilter () const =0
	Returns the head Filter.

virtual void	clearFilters ()=0
	Clear the list of filters by removing all the filters in it.

virtual void	close ()=0
	Release any resources allocated within the appender such as file handles, network connections, etc.

virtual void	doAppend (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)=0
	Log in `Appender` specific way.

virtual LogString	getName () const =0
	Get the name of this appender.

virtual void	setLayout (const LayoutPtr layout)=0
	Set the Layout for this appender.

virtual LayoutPtr	getLayout () const =0
	Returns this appenders layout.

virtual void	setName (const LogString &name)=0
	Set the name of this appender.

virtual bool	requiresLayout () const =0
	Configurators call this method to determine if the appender requires a layout.

Public Member Functions inherited from log4cxx::spi::OptionHandler
virtual	~OptionHandler ()

virtual void	activateOptions (helpers::Pool &p)=0
	Activate the options that were previously set with calls to option setters.

virtual void	setOption (const LogString &option, const LogString &value)=0
	Set `option` to `value`.

Public Member Functions inherited from log4cxx::helpers::Object
virtual	~Object ()

virtual const helpers::Class &	getClass () const =0

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

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

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

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

static const int	MAX_EVENT_LEN
	Unused.

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

void	cleanUp (helpers::Pool &p) override

int	getDefaultDelay () const override

int	getDefaultPort () const override

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

Protected Member Functions inherited from log4cxx::net::SocketAppenderSkeleton
	SocketAppenderSkeleton (std::unique_ptr< SocketAppenderSkeletonPriv > priv)

virtual void	setSocket (log4cxx::helpers::SocketPtr &socket, log4cxx::helpers::Pool &p)=0

virtual void	cleanUp (log4cxx::helpers::Pool &p)=0

virtual int	getDefaultDelay () const =0

virtual int	getDefaultPort () const =0

Protected Member Functions inherited from log4cxx::AppenderSkeleton
	AppenderSkeleton (LOG4CXX_PRIVATE_PTR(AppenderSkeletonPrivate) priv)

virtual void	append (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &p)=0
	Subclasses of `AppenderSkeleton` should implement this method to perform actual logging.

void	doAppendImpl (const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool)

Detailed Description

Sends spi::LoggingEvent elements to a remote a log server, usually in XML format.

Here is an example configuration that writes JSON to the TCP input plugin of a fluent-bit log server running on the same system as the application:

<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="A1" class="XMLSocketAppender">
  <param name="RemoteHost" value="localhost" />
  <param name="Port"       value="5170" />
  <layout class="JSONLayout"/>
</appender>
<root>
  <priority value ="INFO" />
  <appender-ref ref="A1" />
</root>
</log4j:configuration>

XMLSocketAppender has the following properties:

The event will be logged with the same time stamp, NDC, location info as if it were logged locally by the client.
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 an XMLSocketAppender 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 XMLSocketAppender explicitly. See also next item.

Long lived applications which create/destroy many XMLSocketAppender instances should be aware of this destruction problem. Most other applications can safely ignore it.
If the application hosting the XMLSocketAppender exits before the XMLSocketAppender 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 XMLSocketAppender either explicitly or by calling the LogManager::shutdown method before exiting the application.

Constructor & Destructor Documentation

◆ XMLSocketAppender() [1/3]

log4cxx::net::XMLSocketAppender::XMLSocketAppender ( )

◆ ~XMLSocketAppender()

log4cxx::net::XMLSocketAppender::~XMLSocketAppender ( )

◆ XMLSocketAppender() [2/3]

log4cxx::net::XMLSocketAppender::XMLSocketAppender	(	helpers::InetAddressPtr	address,
		int	port
	)

Connects to remote server at address and port.

◆ XMLSocketAppender() [3/3]

log4cxx::net::XMLSocketAppender::XMLSocketAppender	(	const LogString &	host,
		int	port
	)

Connects to remote server at host and port.

Member Function Documentation

◆ append()

void log4cxx::net::XMLSocketAppender::append	(	const spi::LoggingEventPtr &	event,
		helpers::Pool &	p
	)

overrideprotectedvirtual

Subclasses of AppenderSkeleton should implement this method to perform actual logging.

See also AppenderSkeleton::doAppend method.

Implements log4cxx::AppenderSkeleton.

◆ cleanUp()

void log4cxx::net::XMLSocketAppender::cleanUp ( helpers::Pool & p )

overrideprotectedvirtual

Implements log4cxx::net::SocketAppenderSkeleton.

◆ getDefaultDelay()

int log4cxx::net::XMLSocketAppender::getDefaultDelay ( ) const

overrideprotectedvirtual

Implements log4cxx::net::SocketAppenderSkeleton.

◆ getDefaultPort()

int log4cxx::net::XMLSocketAppender::getDefaultPort ( ) const

overrideprotectedvirtual

Implements log4cxx::net::SocketAppenderSkeleton.

◆ setSocket()

void log4cxx::net::XMLSocketAppender::setSocket	(	log4cxx::helpers::SocketPtr &	socket,
		helpers::Pool &	p
	)

overrideprotectedvirtual

Implements log4cxx::net::SocketAppenderSkeleton.

Member Data Documentation

◆ DEFAULT_PORT

int log4cxx::net::XMLSocketAppender::DEFAULT_PORT

static

The default port number of remote logging server (4560).

◆ DEFAULT_RECONNECTION_DELAY

int log4cxx::net::XMLSocketAppender::DEFAULT_RECONNECTION_DELAY

static

The default reconnection delay (30000 milliseconds or 30 seconds).

◆ MAX_EVENT_LEN

const int log4cxx::net::XMLSocketAppender::MAX_EVENT_LEN

static

Unused.

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

xmlsocketappender.h

Public Member Functions

Static Public Attributes

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ XMLSocketAppender() [1/3]

◆ ~XMLSocketAppender()

◆ XMLSocketAppender() [2/3]

◆ XMLSocketAppender() [3/3]

Member Function Documentation

◆ append()

◆ cleanUp()

◆ getDefaultDelay()

◆ getDefaultPort()

◆ setSocket()

Member Data Documentation

◆ DEFAULT_PORT

◆ DEFAULT_RECONNECTION_DELAY

◆ MAX_EVENT_LEN