SK.gnome.dwarf.log
Class SyslogLogger

java.lang.Object
  SK.gnome.dwarf.GenericService
      SK.gnome.dwarf.thread.ThreadService
          SK.gnome.dwarf.log.GenericLogger
              SK.gnome.dwarf.log.SyslogLogger

All Implemented Interfaces:

Logger, java.lang.Runnable, Service

public class SyslogLogger

extends GenericLogger

The syslog logger.

This logger forwards the log messages to a syslog server. The syslog server is a standard TCP/IP network service described by the RFC 3164. It listens on UDP port 514 for incoming event notification messages, collects them and either writes to a physical medium or forwards to another syslog server.

The address of the remote syslog server can be specified via the setAddress(InetAddress) method. The setFacility(int) method specifies the facility of the generated syslog messages. The default facility is local0, but you may use another facility, if desired.

See the write(long, String, LogLevel, String, Throwable) method for detailed information about the logging process.

Field Summary

protected java.net.InetAddress	address The address of the remote syslog server.
protected int	facility The facility of generated syslog messages.
protected boolean	hostname Whether to send the HOSTNAME header field.
protected int	port The UDP port on the remote syslog server.
protected java.net.DatagramSocket	socket The datagram socket for sending the messages.

Fields inherited from class SK.gnome.dwarf.log.GenericLogger

facilities, levels, lock, LOG_FACILITY_ALL

Fields inherited from class SK.gnome.dwarf.thread.ThreadService

daemon, thread

Fields inherited from class SK.gnome.dwarf.GenericService

initParameters, parent

Fields inherited from interface SK.gnome.dwarf.Service

INITIALIZED, LOG_DEBUG, LOG_ERROR, LOG_FATAL, LOG_INFO, LOG_TRACE, LOG_WARN, LOG_XFER, SHUTDOWN, STARTED, STOPPED

Constructor Summary

SyslogLogger(java.lang.String name)
Creates a new SyslogLogger.

Method Summary

void	init(Server parent) Inititalizes the service.
void	setAddress(java.net.InetAddress address) Sets the address of the remote syslog server.
void	setFacility(int facility) Sets the facility of the generated syslog messages.
void	setPort(int port) Sets the UDP port of the remote syslog server.
void	setSendHostname(boolean enable) Enables or disables sending of HOSTNAME field in the header.
void	shutdown() Shuts down the service and closes the datagram socket.
protected boolean	wouldLog(java.lang.String facility, LogLevel level) Decides whether the logger would log a message with the given loggging level and facility.
protected void	write(long time, java.lang.String facility, LogLevel level, java.lang.String message, java.lang.Throwable error) Sends the message to the syslog server.

Methods inherited from class SK.gnome.dwarf.log.GenericLogger

enableThread, getLastAccessed, log, log, loop, setFacilities, setLevels, setMarkInterval, setRepeatedInterval, start

Methods inherited from class SK.gnome.dwarf.thread.ThreadService

finish, run, setDaemon, stop

Methods inherited from class SK.gnome.dwarf.GenericService

getAuthenticator, getAuthFacility, getFullName, getInitParameter, getInitParameterNames, getLogFacility, getLogger, getName, getParameters, getPrincipal, getShutdownTimeout, getState, log, log, login, logout, setAuthFacility, setInitParameters, setLogFacility, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

socket

protected java.net.DatagramSocket socket

The datagram socket for sending the messages.

It is initialized in the init(Server) method. The access to the socket must be synchronized.

address

protected java.net.InetAddress address

The address of the remote syslog server.

See Also:

setAddress(InetAddress)

port

protected int port

The UDP port on the remote syslog server.

Default: 514

See Also:

setPort(int)

facility

protected int facility

The facility of generated syslog messages.

Default: 16

See Also:

setFacility(int)

hostname

protected boolean hostname

Whether to send the HOSTNAME header field.

Default: true

See Also:

setSendHostname(boolean)

Constructor Detail

SyslogLogger

public SyslogLogger(java.lang.String name)

Creates a new SyslogLogger.

Method Detail

setAddress

public void setAddress(java.net.InetAddress address)

Sets the address of the remote syslog server.

This is the address of the syslog server the messages will be routed to.

Parameters:

address - the inet address

See Also:

address

setPort

public void setPort(int port)

Sets the UDP port of the remote syslog server.

Normally, the default UDP port number 514 is used for the syslog service. You should never change this value.

Parameters:

port - the port number

See Also:

port

setFacility

public void setFacility(int facility)

Sets the facility of the generated syslog messages.

Typically, one of the local use facilities or the user level facility should be used by the services which have not been assigned a concrete facility number. The following facilities are defined byt the RFC 3164:

         Numerical             Facility
           Code
 
            0             kernel messages
            1             user-level messages
            2             mail system
            3             system daemons
            4             security/authorization messages (note 1)
            5             messages generated internally by syslogd
            6             line printer subsystem
            7             network news subsystem
            8             UUCP subsystem
            9             clock daemon (note 2)
           10             security/authorization messages (note 1)
           11             FTP daemon
           12             NTP subsystem
           13             log audit (note 1)
           14             log alert (note 1)
           15             clock daemon (note 2)
           16             local use 0  (local0)
           17             local use 1  (local1)
           18             local use 2  (local2)
           19             local use 3  (local3)
           20             local use 4  (local4)
           21             local use 5  (local5)
           22             local use 6  (local6)
           23             local use 7  (local7)
 

The SyslogLogger uses local0 facility by default.

Parameters:

facility - the facility code

See Also:

facility

setSendHostname

public void setSendHostname(boolean enable)

Enables or disables sending of HOSTNAME field in the header.

The syslog protocol description states that the HOSTNAME field should be send along with the TIMESTAMP info in the message packet header. However, some syslog servers would log this hostname information twice, so this method may be used to prevent such information redundancy. The sending of hostname is enabled by default for conformance with the RFC document.

Parameters:

enable - true to enable sending of hostname

See Also:

hostname

init

public void init(Server parent)
          throws ServiceException

Inititalizes the service.

The new DatagramSocket is created and connected to the address and port. The socket reference is then assigned to the socket field.

Specified by:

init in interface Service

Overrides:

init in class GenericService

Throws:

ServiceException

shutdown

public void shutdown()

Shuts down the service and closes the datagram socket.

Specified by:

shutdown in interface Service

Overrides:

shutdown in class GenericLogger

wouldLog

protected boolean wouldLog(java.lang.String facility,
                           LogLevel level)

Decides whether the logger would log a message with the given loggging level and facility.

It first checks whether the UDP socket has been initialized and then calls the overriden wouldLog method and returns its result.

Overrides:

wouldLog in class GenericLogger

Parameters:

facility - the logging facility

level - the logging level

Returns:

true if the logger would log the message, false otherwise

write

protected void write(long time,
                     java.lang.String facility,
                     LogLevel level,
                     java.lang.String message,
                     java.lang.Throwable error)

Sends the message to the syslog server.

This method formats the message and sends it to the remote syslog server via the socket.

The Dwarf logging levels are mapped to severity levels defined by the protocol specification as follows:

         Dwarf         Syslog           Severity
         Level          Code 
 
       LOG_FATAL  =<     0       Emergency: system is unusable
                         1       Alert: action must be taken immediately
                         2       Critical: critical conditions
       LOG_ERROR  =<     3       Error: error conditions
       LOG_WARN   =<     4       Warning: warning conditions
                         5       Notice: normal but significant condition
       LOG_INFO   =<     6       Informational: informational messages
       LOG_DEBUG  =<     7       Debug: debug-level messages
 

Since the length of a syslog datagram packet is limited to 1024 bytes, any messages longer than this limit will be truncated to 1kB automatically.

Specified by:

write in class GenericLogger

Parameters:

time - the current time of the logged event

facility - the log facility

level - the log level

message - the message

error - the error (optional)

See Also:

GenericLogger.log(String, LogLevel, String), GenericLogger.log(String, LogLevel, String, Throwable)