XML Config

This page describes xml config.

Structure

The top element is config. It contains three types of optional elements:

appender - describes how/where to write/stream/filter messages.
logger - describes a level filter and what appenders to use.
service - describes how to route messages from loggers to appenders.

<config>
    <appender name="console" factory="com.epam.deltix.gflog.core.appender.ConsoleAppenderFactory"/>
   
    <logger>
        <appender-ref ref="console"/>
    </logger>

    <service/>
</config>

Appender

Attribute	Default	Required	Description
name		Y	Appender name.
factory		Y	Factory class to create an instance.
level	TRACE	N	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.

Usually contains the specific attributes and elements depending on the type. For instance:

<appender name="file" factory="com.epam.deltix.gflog.core.appender.FileAppenderFactory" file="log.txt">
    <layout template="%d %p '%c' [%t] %m%n"/>
</appender>

Logger

Attribute	Default	Description
name	""	Log name.
level	INFO	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.

Contains appender-ref element to select which appenders to use:

<logger level="DEBUG" name="my-logger">
    <appender-ref ref="console"/>
    <appender-ref ref="file"/>
</logger>

Service

Attribute	Default	Description
factory	com.epam.deltix.gflog.core.service.AsyncLogServiceFactory	Factory class to create an instance.

Contains the specific attributes and elements depending on the type. For instance:

<service entryEncoding="UTF-8">
    <idle-strategy maxSpins="5"/>
</service>

Appenders

Console

Writes messages to the console.

Attribute	Default	Required	Description
name		Y	Appender name.
factory		Y	com.epam.deltix.gflog.core.appender.ConsoleAppenderFactory
level	TRACE	N	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.
bufferCapacity	2M	N	Buffer capacity. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
flushCapacity	bufferCapacity*	N	Max size to flush at once. Window's default is 16K. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
wrap	false	N	Uses a wrapper over the system stream. Otherwise tries to use the underlying FileChannel directly.
stderr	false	N	Uses the standard error stream instead of the standard output stream.

Contains an optional layout element:

<appender name="console" factory="com.epam.deltix.gflog.core.appender.ConsoleAppenderFactory" bufferCapacity="1M" stderr="true">
    <layout template="%d (${user.name}) %p '%c' [%t]: %m%n"/>
</appender>

File

Writes messages to a file.

Attribute	Default	Required	Description
name		Y	Appender name.
factory		Y	com.epam.deltix.gflog.core.appender.FileAppenderFactory
file		Y	File path to write to.
level	TRACE	N	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.
append	true	N	Appends to the existing file or truncates it.
bufferCapacity	2M	N	Buffer capacity. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
flushCapacity	bufferCapacity	N	Max size to flush at once. Supports suffixes: k/kb/K/KB/m/mb/M/MB.

Contains an optional layout element:

<appender name="console" factory="com.epam.deltix.gflog.core.appender.FileAppenderFactory" file="my-log.log">
    <layout template="%d (${user.name}) %p '%c' [%t]: %m%n"/>
</appender>

Daily Rolling File

Writes messages to files. Starts a new file on daily basis or if the current file exceeds the configured size. Deletes old files if configured.

The file name pattern: ${directory}/${name}${suffix}${index}${extension}.

For file "my-dir/my-file.log" and fileSuffixTemplate "-yyyy-MM-dd" it would be: "my-dir/my-file-2021-02-15.0.log".

Attribute	Default	Required	Description
name		Y	Appender name.
factory		Y	com.epam.deltix.gflog.core.appender.DailyRollingFileAppenderFactory
file		Y	File path to write to. Pattern: ${directory}/${name}${suffix}${index}${extension}.
fileSuffixTemplate	-yyyy-MM-dd	N	File suffix template. Pattern: ${directory}/${name}${suffix}${index}${extension}.
level	TRACE	N	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.
append	true	N	Appends to the existing file or truncates it.
maxFiles	0	N	Preserves only N last files and removes old ones. Enabled if positive.
maxFileSize	0	N	Triggers file rolling if the current file exceeds the specified size. Enabled if positive. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
zoneId	system	N	Which time zone to use when rolling files.
bufferCapacity	2M	N	Buffer capacity. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
flushCapacity	bufferCapacity	N	Max size to flush at once. Supports suffixes: k/kb/K/KB/m/mb/M/MB.

Contains an optional layout element:

<appender name="file" factory="com.epam.deltix.gflog.core.appender.DailyRollingFileAppenderFactory"
              file="gflog-sample/build/tmp/file.log" fileSuffixTemplate="_yyyy-MM-dd-HH-mm-ss"
              maxFiles="2" maxFileSize="1KB"/>

Tcp

Sends messages through a TCP connection to a remote side.

Attribute	Default	Required	Description
name		Y	Appender name.
factory		Y	com.epam.deltix.gflog.core.appender.TcpAppenderFactory
host		Y	Remote host.
port		Y	Remote port.
level	TRACE	N	Level filter. Values: TRACE, DEBUG, INFO, WARN, ERROR, FATAL.
bufferCapacity	2M	N	Buffer capacity. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
flushCapacity	bufferCapacity	N	Max size to flush at once. Supports suffixes: k/kb/K/KB/m/mb/M/MB.
connectTimeout	5s	N	Connect timeout on startup. Application threads can be blocked.
reconnectInitialPeriod	5s	N	Reconnect period is reset to this value on a successful connection attempt.
reconnectMaxPeriod	10m	N	Reconnect period is doubled gradually up to this value on each consequent failed connection attempt.
sendTimeout	5s	N	Disconnects after this period if a message can't be sent to socket because of backpressure.
socketSendBufferCapacity	2M	N	Socket send buffer capacity. 0 is OS's default.
socketReceiveBufferCapacity	0	N	Socket receive buffer capacity. 0 is OS's default.
socketTcpNoDelay	false	N	Socket tcp no delay. true is to enable Nagle's algorithm.

Contains an optional layout element:

<appender name="gelf" factory="com.epam.deltix.gflog.core.appender.TcpAppenderFactory"
          host="localhost" port="5555" connectTimeout="1s" reconnectInitialPeriod="1ms" sendTimeout="1s">

    <layout factory="com.epam.deltix.gflog.core.layout.GelfLayoutFactory">
        <additional-fields>
            <entry key="container" value="${container.name}"/>
        </additional-fields>
    </layout>
</appender>

Layouts

Template

%p - log level.
%c - log name.
%t - thread name.
%m - message.
%n - line break.
%d - date time. By default uses yyyy-MM-dd HH:mm:ss.SSS format. Custom format can be specified using {} suffix: or use custom format. For example, ISO 8601 format can be specified as %d{yyyy-MM-dd'T'HH:mm:ss.SSS'Z'}.

<!-- 2021-03-05 17:14:38.154 INFO [main] Hello there! -->
<layout/>

<!-- 2021-03-05 17:15:40.879 INFO 'com.epam.deltix.gflog.sample.ConfigSample' [main]: Hello there! -->
<layout template="%d %p '%c' [%t]: %m%n"/>

<!-- 2021-03-05 17:09:04.612 (my-user) INFO 'ConfigSample' [main]: Hello there! -->
<layout template="%d (${user.name}) %p '%c{1}' [%t]: %m%n"/>

<!-- 5 Mar 2021 17:26:42.990 INFO @ Hello there! -->
<layout template="%d{d MMM yyyy HH:mm:ss.SSS} %p \0x40 %m%n"/>

<!-- 2021-03-05T17:26:42.990Z INFO @ Hello there! --> 
<layout template="%d{yyyy-MM-dd'T'HH:mm:ss.SSS'Z'} %p    [%t]: %m%n" zoneId="UTC"/>

Gelf

You can stream log messages to Gray Log by using com.epam.deltix.gflog.core.layout.GelfLayout and com.epam.deltix.gflog.core.appender.TcpAppender.

You can use the following config sample to configure GF Log:

<config>
    <appender name="gelf" factory="com.epam.deltix.gflog.core.appender.TcpAppenderFactory" host="10.10.87.126" port="11111">
        <layout factory="com.epam.deltix.gflog.core.layout.GelfLayoutFactory">
            <additional-fields>
                <entry key="key" value="value"/>
            </additional-fields>
        </layout>
    </appender>

    <logger>
        <appender-ref ref="gelf"/>
    </logger>

</config>

A message sample from the config above will be:

{  
   "version":"1.1",
   "level":4,
   "host":"localhost",
   "_key":"value",
   "short_message":"Hey there!",
   "_logger":"java.util.Object",
   "_thread":"main",
   "timestamp":1345.234567890
}\0x00

Services

Async

Attribute	Default	Description
factory	default	com.epam.deltix.gflog.core.service.AsyncLogServiceFactory
entryEncoding	ASCII	Which encoding to use. Values: ASCII, UTF-8.
entryInitialCapacity	4K	Initial entry size per thread.
entryMaxCapacity	64K	Max entry size per thread.
entryTruncationSuffix	>>	Truncation suffix to append when exceeding the max entry size.
bufferCapacity	8M	Ring buffer capacity in bytes. The ring buffer is used to pass messages to the background thread.
overflowStrategy	WAIT	What to do if the ring buffer is full. Values: WAIT, DISCARD.

Contains an optional idleStrategy element to specify how to idle when no messages to process:

<service entryEncoding="UTF-8" entryInitialCapacity="16K" entryMaxCapacity="128K" entryTruncationSuffix="TRNCTD>>" 
    bufferCapacity="16M" overflowStrategy="DISCARD">
   
    <idle-strategy maxSpins="0" maxYields="10" minParkPeriod="1000" maxParkPeriod="100000"/>
</service>

Sync

Good for testing to not mess up messages from different tests.

Attribute	Default	Description
factory	change to	com.epam.deltix.gflog.core.service.SyncLogServiceFactory
entryEncoding	ASCII	Which encoding to use. Values: ASCII, UTF-8.
entryInitialCapacity	4K	Initial entry size per thread.
entryMaxCapacity	64K	Max entry size per thread.
entryTruncationSuffix	>>	Truncation suffix to append when exceeding the max entry size.

XML Config - epam/gflog GitHub Wiki

XML Config

Structure

Appender

Logger

Service

Appenders

Console

File

Daily Rolling File

Tcp

Layouts

Template

Gelf

Services

Async

Sync

⚠️ GitHub.com Fallback ⚠️

XML Config - epam/gflog GitHub Wiki

XML Config

Structure

Appender

Logger

Service

Appenders

Console

File

Daily Rolling File

Tcp

Layouts

Template

Gelf

Services

Async

Sync

⚠️ **GitHub.com Fallback** ⚠️

⚠️ GitHub.com Fallback ⚠️