Logging

Changing logging levels before startup
OpenSimulator uses the log4net package for logging. This means that every executable you run for OpenSimulator has an accompanying .config file which contains the logging configuration

For instance


 * OpenSim.exe -> config is OpenSim.exe.config
 * OpenSim.32BitLaunch.exe -> config is OpenSim.32BitLaunch.exe.config
 * Robust.exe -> config is Robust.exe.config

The OpenSim.exe.config file looks like this.

                <appender-ref ref="NHibernateFileLog"/> <level value="DEBUG" /> <appender-ref ref="Console" /> <appender-ref ref="LogFileAppender" />

This looks rather complicated, but if you want to change the level of messages logged, then you could change the value in the section (right at the end) which is

<level value="DEBUG" />

in the example above to something different, e.g.

<level value="WARN" />

which will only display warning and error level log messages. Permissible values are ALL, DEBUG, INFO, WARN, ERROR, FATAL, OFF

You can also see from the OpenSim.exe.config file that log files are written to OpenSim.log (as well as the console).

Rolling file appender and maximum log-file size
Log4net provides several log-file appenders. One of them is the RollingFileAppender, which limits log-file size and rotates log-files automatically. To use this appender, add the following section to the log4net-configuration:

<appender name="RollingFileAppender" type="log4net.Appender.RollingFileAppender"> <file value="OpenSim.log" /> <appendToFile value="true" /> <maximumFileSize value="1000KB" /> <maxSizeRollBackups value="2" /> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%date %-5level - %logger %message%newline" />

The maximum size can be set in the maximumFileSize element, the maxSizeRollBackups element determines the maximum number of rolling log-files. So, the setting above will create a log-file named OpenSim.log with a maximum size of 1000KB. When the limit is reached, OpenSim.log will be renamed to OpenSim.log.1, and a fresh OpenSim.log is started (possibly after renaming OpenSim.log.1 to OpenSim.log.2, should that file exist already).

To use the appender defined above, replace the line <appender-ref ref="LogFileAppender" /> by <appender-ref ref="RollingFileAppender" />

Further information about configuration of log4net can be found on the Log4Net configuration page.

More specialized requirements
As an example, similar to Mantis#2603, if you want logging the XEngine's DEBUG output into a separate file xengine.log, and let only the message with level INFO and higher appear on the console, you can do that by adding the following lines to your OpenSim.exe.config:

<appender name="XengineLogFileAppender" type="log4net.Appender.FileAppender"> <file value="xengine.log" /> <appendToFile value="true" /> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%date %-5level - %logger %message%newline" /> <appender name="XengineConsole" type="OpenSim.Framework.Console.OpenSimAppender, OpenSim.Framework.Console"> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%date{HH:mm:ss} - %message%newline" /> <filter type="log4net.Filter.LevelRangeFilter"> <levelMin value="INFO" /> <levelMax value="FATAL" /> <logger name="OpenSim.Region.ScriptEngine.XEngine.XEngine" additivity="false"> <appender-ref ref="XengineLogFileAppender" /> <appender-ref ref="XengineConsole" />

(if there is a shorter way to do it, please replace those lines above) ;-)

Or, as an easier example, if you want to have the normal logging, except for the HttpServers which you want only INFO messages for, you can add the following lines after the  -tag:

<logger name="OpenSim.Framework.Servers.HttpServerLogWriter"> <level value="INFO" />

MySQL Logging
This example can be used to log the data to a MySQL table.

Step 1: Create a MySQL Database "OSLog" and add the following table to which the data will be stored to

CREATE TABLE `opensim_log` (  `ID` int(10) NOT NULL AUTO_INCREMENT,   `DATE` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,   `Level` varchar(100) DEFAULT ,   `Logger` varchar(512) DEFAULT ,   `Message` varchar(1000) DEFAULT '',   PRIMARY KEY (`ID`)   );

Step 2: Replace the "LogFileAppender" appender Section with

<appender name="MySql_ADONetAppender" type="log4net.Appender.ADONetAppender"> <bufferSize value="5" /> <connectionType value="MySql.Data.MySqlClient.MySqlConnection, MySql.Data"/> <connectionString value="Server=localhost;Database=OSLog;Uid=DBUsername;Pwd=DBUserPassword"/> <commandText value="INSERT INTO opensim_log(Date,Level,Logger,Message) VALUES (@log_date, @log_level, @logger, @message)"/> <parameterName value="@log_date"/> <dbType value="DateTime"/> <layout type="log4net.Layout.RawTimeStampLayout"/> <parameterName value="@log_level"/> <dbType value="String"/> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%level"/> <parameterName value="@logger"/> <dbType value="String"/> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%logger"/> <parameterName value="@message"/> <dbType value="String"/> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%message"/>

To use the appender defined above, replace the line <appender-ref ref="LogFileAppender" /> by <appender-ref ref="MySql_ADONetAppender" />

Note: One also can continue logging to File, in which case we do not need to replace the LogFileAppender section.

Setting log levels during runtime
It isn't currently possible to change the level of logging to the log file during runtime. However, it is possible to change the level sent to the console. You can do this by executing the

set log level [ ]

command. For example

set log level error

will mean only errors are sent to the console. The log still receives messages that meet the level set in the OpenSim.exe.config file at startup.

get log level

will tell you what the current console logging level is.

Changes to the log level sent to the console will not persist over restarts. If you want the change to be permanent, you can set a threshold value in the ConsoleAppender in a config file such as OpenSim.exe.config as described above.

Specifying log file location per instance
Logging for multiple instances run from a single OpenSim.exe isn't something that the default log4net configuration handles. Fortunately, log4net accepts environment variables. This allows a script wrapping OpenSim.exe to specify a log location by setting an environment variable. An example snippet for Opensim.exe.config might be:

<appender name="LogFileAppender" type="log4net.Appender.FileAppender"> <file type="log4net.Util.PatternString" value="%env{OSIM_LOGPATH}\OpenSim.log" /> <appendToFile value="true" /> <layout type="log4net.Layout.PatternLayout"> <conversionPattern value="%date %-5level - %logger %message%newline" />

When OpenSimulator is running under Mono in Linux, then you should have something in your startscript.sh like

export LOGFILEPATH='/some/absolute/path/'

... and in Opensim.exe.config

<file type="log4net.Util.PatternString" value="${LOGFILEPATH}OpenSim.log" />