4.6.1. Setting up Logging in Tomcat
This section covers the setup of logging in development environment.
Running Gradle setupTomcat task installs the Tomcat server into the project directory and performs its additional configuration. Particularly, setenv.bat
and setenv.sh
files are created in the tomcat/bin
subfolder, and logback.xml
is created in the tomcat/conf
subfolder.
Among other things, the setenv.*
files define loading parameters for the logback.xml
configuration file using the CATALINA_OPTS
variable.
logback.xml
defines logging configuration. The file has the following structure:
-
appender
elements define the "output device" for the log. The main appenders areFILE
andCONSOLE
. Thelevel
parameter ofThresholdFilter
defines the message threshold. By default, it isDEBUG
for a file andINFO
for console. It means thatERROR
,WARN
,INFO
andDEBUG
messages are written to a file, whileERROR
,WARN
andINFO
are written to console.The path to the log file for the file appender is defined in the
file
parameter. The default istomcat/logs/app.log
. -
logger
elements define the logger parameters that are used to print messages from the program code. Logger names are hierarchical, i.e. the settings of thecom.company.sample
logger have effect on thecom.company.sample.core.CustomerServiceBean
andcom.company.sample.web.CustomerBrowse
loggers, if the loggers do not explicitly override the settings with their own.Minimum logging level is defined by the
level
attribute. For example, if the category isINFO
, thenDEBUG
andTRACE
messages will not be logged. It should be kept in mind that message logging is also affected by the level threshold set in the appender.
You can quickly change logger levels and appender thresholds for a running server using the Administration > Server Log screen available in the web client. Any changes to the logging settings are effective only during server runtime and are not saved to a file. The screen also enables viewing and loading log files from the server logs folder (tomcat/logs).
The platform automatically adds the following information to the messages written to the file log:
-
application – the name of the web application that has logged the message. This information enables identifying messages from different application blocks (Middleware, Web Client), since they are written into the same file.
-
user – the login name of the user who invoked the code logging the message. This helps to track activity of a certain user in the log. If the code that logged a message was not invoked within a specific user session, the user information is not added.
For example, the following message has been written to the log by the code of the Middleware block (app-core
), running under the admin
user:
16:12:20.498 DEBUG [http-nio-8080-exec-7/app-core/admin] com.haulmont.cuba.core.app.DataManagerBean - loadList: ...