log4j logging hierarchy order

Question

What is the hierarchy of log4j logging   DEBUG INFO WARN ERROR FATAL   Which one provides the highest logging which would be helpful to troubleshoot issues  Can any one provide the order or hierarchy in which logging take place from highest to lowest  Thanks

User · Answer

Taken from http   javarevisited blogspot com 2011 05 top-10-tips-on-logging-in-java html   DEBUG is the lowest restricted java logging level and we should write everything we need to debug an application  this java logging mode should only be used on Development and Testing environment and must not be used in production environment   INFO is more restricted than DEBUG java logging level and we should log messages which are informative purpose like Server has been started  Incoming messages  outgoing messages etc in INFO level logging in java   WARN is more restricted than INFO java logging level and used to log warning sort of messages e g  Connection lost between client and server  Database connection lost  Socket reaching to its limit  These messages and java logging level are almost important because you can setup alert on these logging messages in java and let your support team monitor health of your java application and react on this warning messages  In Summary WARN level is used to log warning message for logging in Java   ERROR is the more restricted java logging level than WARN and used to log Errors and Exception  you can also setup alert on this java logging level and alert monitoring team to react on this messages  ERROR is serious for logging in Java and you should always print it   FATAL java logging level designates very severe error events that will presumably lead the application to abort  After this mostly your application crashes and stopped   OFF java logging level has the highest possible rank and is intended to turn off logging in Java

User · Answer

Use the force  read the source  excerpt from the Priority and Level class compiled  TRACE level was introduced in version 1 2 12    public final static int OFF INT   Integer MAX VALUE  public final static int FATAL INT   50000  public final static int ERROR INT   40000  public final static int WARN INT    30000  public final static int INFO INT    20000  public final static int DEBUG INT   10000  public static final int TRACE INT   5000   public final static int ALL INT   Integer MIN VALUE     or the log4j API for the Level class  which makes it quite clear   When the library decides whether to print a certain statement or not  it computes the effective level of the responsible Logger object  based on configuration  and compares it with the LogEvent s level  depends on which method was used in the code  ndash  trace debug     fatal   If LogEvent s level is greater or equal to the Logger s level  the LogEvent is sent to appender s   ndash   printed   At the core  it all boils down to an integer comparison and this is where these constants come to action

User · Answer

Hierarchy order    ALL TRACE DEBUG INFO WARN ERROR FATAL OFF

User · Answer

OFF FATAL ERROR WARN INFO DEBUG TRACE ALL

User · Answer

Hierarchy of log4j logging levels are as follows in Highest to Lowest order     TRACE  DEBUG  INFO  WARN  ERROR  FATAL  OFF   TRACE log level provides highest logging which would be helpful to troubleshoot issues  DEBUG log level is also very useful to trouble shoot the issues   You can also refer this link for more information about log levels    https   logging apache org log4j 2 0 manual architecture html

User · Answer

This table might be helpful for you     Going down the first column  you will see how the log works in each level  i e for WARN   FATAL  ERROR and WARN  will be visible  For OFF  nothing will be visible

[logging] log4j logging hierarchy order

Examples related to logging

Examples related to log4j