Chapter 13. Configuring logging

Level

Description

FATAL

Critical failures with complete inability to serve any kind of request.

ERROR

A significant error or problem leading to the inability to process requests.

WARN

A non-critical error or problem that might not require immediate correction.

INFO

Red Hat build of Keycloak lifecycle events or important information. Low frequency.

DEBUG

More detailed information for debugging purposes, such as database logs. Higher frequency.

TRACE

Most detailed debugging information. Very high frequency.

ALL

Special level for all log messages.

OFF

Special level to turn logging off entirely (not recommended).

Symbol

Summary

Description

%%

%

Renders a simple % character.

%c

Category

Renders the log category name.

%d{xxx}

Date

Renders a date with the given date format string.String syntax defined by java.text.SimpleDateFormat

%e

Exception

Renders a thrown exception.

%h

Hostname

Renders the simple host name.

%H

Qualified host name

Renders the fully qualified hostname, which may be the same as the simple host name, depending on the OS configuration.

%i

Process ID

Renders the current process PID.

%m

Full Message

Renders the log message and an exception, if thrown.

%n

Newline

Renders the platform-specific line separator string.

%N

Process name

Renders the name of the current process.

%p

Level

Renders the log level of the message.

%r

Relative time

Render the time in milliseconds since the start of the application log.

%s

Simple message

Renders only the log message without exception trace.

%t

Thread name

Renders the thread name.

%t{id}

Thread ID

Render the thread ID.

%z{<zone name>}

Timezone

Set the time zone of log output to <zone name>.

%L

Line number

Render the line number of the log message.