Quarkus - Configuring Logging

This guide explains logging and how to configure it.

Run Time Configuration

Run time configuration of logging is done through the normal application.properties file.

Configuration property fixed at build time - ️ Configuration property overridable at runtime

Configuration property

Type

Default

The default log level

Level

The default minimum log level

Level

INFO

Logging categories

Type

Default

The minimum level that this category can be set to

string

inherit

The log level level for this category

string

inherit

Console logging

Type

Default

If console logging should be enabled

boolean

true

string

%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p [%c{3.}] (%t) %s%e%n

The console log level

Level

ALL

If the console logging should be in color. If undefined quarkus takes best guess based on operating system and environment.

boolean

Specify how much the colors should be darkened

int

0

Indicates whether to log asynchronously

boolean

false

The queue length to use before flushing writing

int

512

Determine whether to block the publisher (rather than drop the message) when the queue is full

block, discard

block

File logging

Type

Default

If file logging should be enabled

boolean

false

The log format

string

%d{yyyy-MM-dd HH:mm:ss,SSS} %h %N[%i] %-5p [%c{3.}] (%t) %s%e%n

The level of logs to be written into the file.

Level

ALL

The name of the file in which logs will be written.

File

quarkus.log

Indicates whether to log asynchronously

boolean

false

The queue length to use before flushing writing

int

512

Determine whether to block the publisher (rather than drop the message) when the queue is full

block, discard

block

The maximum file size of the log file after which a rotation is executed.

MemorySize

The maximum number of backups to keep.

int

1

File handler rotation file suffix. Example fileSuffix: .yyyy-MM-dd

string

Indicates whether to rotate log files on server initialization.

boolean

true

Syslog logging

Type

Default

If syslog logging should be enabled

boolean

false

The IP address and port of the syslog server

host:port

localhost:514

The app name used when formatting the message in RFC5424 format

string

The name of the host the messages are being sent from

string

Sets the facility used when calculating the priority of the message as defined by RFC-5424 and RFC-3164

kernel, user-level, mail-system, system-daemons, security, syslogd, line-printer, network-news, uucp, clock-daemon, security2, ftp-daemon, ntp, log-audit, log-alert, clock-daemon2, local-use-0, local-use-1, local-use-2, local-use-3, local-use-4, local-use-5, local-use-6, local-use-7

user-level

Set the SyslogType syslog type this handler should use to format the message sent

rfc5424, rfc3164

rfc5424

Sets the protocol used to connect to the syslog server

tcp, udp, ssl-tcp

tcp

Set to true if the message being sent should be prefixed with the size of the message

boolean

false

Set to true if the message should be truncated

boolean

true

Enables or disables blocking when attempting to reconnect a org.jboss.logmanager.handlers.SyslogHandler.Protocol#TCP TCP or org.jboss.logmanager.handlers.SyslogHandler.Protocol#SSL_TCP SSL TCP protocol

boolean

false

The log message format

string

%d{yyyy-MM-dd HH:mm:ss,SSS} %-5p [%c{3.}] (%t) %s%e%n

The log level specifying, which message levels will be logged by syslog logger

Level

ALL

Indicates whether to log asynchronously

boolean

false

The queue length to use before flushing writing

int

512

Determine whether to block the publisher (rather than drop the message) when the queue is full

block, discard

block

Log cleanup filters - internal use

Type

Default

The message starts to match

list of string

inherit

About the MemorySize format

A size configuration option recognises string in this format (shown as a regular expression): [0-9]+[KkMmGgTtPpEeZzYy]?. If no suffix is given, assume bytes.

Logging categories

Logging is done on a per-category basis. Each category can be independently configured. A configuration which applies to a category will also apply to all sub-categories of that category, unless there is a more specific matching sub-category configuration.

Property Name Default Description

quarkus.log.category."<category-name>".level

INFO [1]

The level to use to configure the category named <category-name>. The quotes are necessary.

The quotes shown in the property name are required as categories normally contain '.' which must be escaped. An example is shown in File TRACE Logging Configuration.

Root logger configuration

The root logger category is handled separately, and is configured via the following properties:

Property Name Default Description

quarkus.log.level

INFO

The default minimum log level for every log category.

Format String

The logging format string supports the following symbols:

Symbol Summary Description

%%

%

Renders a simple % character.

%c

Category

Renders the category name.

%C

Source class

Renders the source class name.[2]

%d{xxx}

Date

Renders a date with the given date format string, which uses the syntax defined by java.text.SimpleDateFormat.

%e

Exception

Renders the thrown exception, if any.

%F

Source file

Renders the source file name.[2]

%h

Host name

Renders the system simple host name.

%H

Qualified host name

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

%i

Process ID

Render the current process PID.

%l

Source location

Renders the source location information, which includes source file name, line number, class name, and method name.[2]

%L

Source line

Renders the source line number.[2]

%m

Full Message

Renders the log message plus exception (if any).

%M

Source method

Renders the source method name.[2]

%n

Newline

Renders the platform-specific line separator string.

%N

Process name

Render the name of the current process.

%p

Level

Render 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 just the log message, with no exception trace.

%t

Thread name

Render the thread name.

%t{id}

Thread ID

Render the thread ID.

%z{<zone name>}

Time zone

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

%X{<MDC property name>}

Mapped Diagnostics Context Value

Renders the value from Mapped Diagnostics Context

%X

Mapped Diagnostics Context Values

Renders all the values from Mapped Diagnostics Context in format {property.key=property.value}

%x

Nested Diagnostics context values

Renders all the values from Nested Diagnostics Context in format {value1.value2}

Examples

Console DEBUG Logging, No color, Shortened Time, Shortened Category Prefixes
quarkus.log.console.enable=true
quarkus.log.console.format=%d{HH:mm:ss} %-5p [%c{2.}] (%t) %s%e%n
quarkus.log.console.level=DEBUG
quarkus.log.console.color=false

quarkus.log.category."io.quarkus".level=DEBUG
If you are adding these properties via command line make sure " is escaped. For example -Dquarkus.log.category.\"io.quarkus\".level=DEBUG.
File TRACE Logging Configuration
quarkus.log.file.enable=true
# Send output to a trace.log file under the /tmp directory
quarkus.log.file.path=/tmp/trace.log
quarkus.log.file.level=TRACE
quarkus.log.file.format=%d{HH:mm:ss} %-5p [%c{2.}] (%t) %s%e%n
# Set 2 categories (io.quarkus.smallrye.jwt, io.undertow.request.security) to TRACE level
quarkus.log.category."io.quarkus.smallrye.jwt".level=TRACE
quarkus.log.category."io.undertow.request.security".level=TRACE

Supported Logging APIs

Applications and components may use any of the following APIs for logging, and the logs will be merged:


1. Some extensions may define customized default log levels for certain categories, in order to reduce log noise by default. Setting the log level in configuration will override any extension-defined log levels.
2. Format sequences which examine caller information may affect performance