How is logging handled?
The Yellowfin & Tomcat log files are extremely useful when troubleshooting issues, or just to find out how things are currently running.
The list of log files (with default options) are listed below:
Log Name | Directory Path | Description |
|---|---|---|
YellowfinInstallLog-YYYYMMDD.log (where YYYYMMDD is the date of installation) | Directly in Yellowfin application folder | This is the installation log file. It logs information about all the chosen installation options, along with any errors encountered during installation. |
YellowfinPatchLog–YYYYMMDD.log (where YYYYMMDD is the date the update was run) | Directly in Yellowfin application folder (if an update has been run) | This is the update installation log file. It logs update information (such as updating the database) and will capture any errors encountered. A log file is created each time you run an update. |
Yellowfin.log | appserver>logs | This is the Yellowfin application log file. It logs processes/tasks that are run in Yellowfin, such as startup, running reports, exporting items, etc. It will also capture most application errors. By default, this file will cycle once it reaches 1024KB , and will create up to nine files (eg, Yellowfin.log.1, Yellowfin.log.2, and so on, with the most recent data always stored in Yellowfin.log and the oldest in the filename with the largest number). The size and number of files can be adjusted if required. Additional information can be logged by enabling debug logging. |
JDBC.log | appserver>logs | This is the Yellowfin configuration database log file. It logs details of the repository database startup and any connection errors. |
source.XXXXX.log (Where XXXXX is the ID of the data source) | appserver>logs | These files contain connection information specific to data sources. Each data source has its own ID, so for each data source, a respective log file exists. Note that a log file for a deleted data source will remain until you manually remove it. |
catalina.YYYY-MM-DD.log (where YYYY-MM-DD is the date Tomcat was started) | appserver>logs | This is the Tomcat startup log file. It logs any errors encountered while starting the service. |
yellowfin-stdout_YYYY-MM-DD.log (where 'yellowfin-' is the name of the Windows service and YYYY-MM-DD is the date Yellowfin was started) | appserver>logs | Note: This file is ONLY present if you have installed Yellowfin as a Windows service. This log file logs information that is usually visible in the console log (the black window that opens when you start Yellowfin). |
yellowfin-stderr_YYYY-MM-DD.log (where 'yellowfin-' is the name of the Windows service and YYYY-MM-DD is the date Yellowfin was started) | appserver>logs | Note: This file is ONLY present if you have installed Yellowfin as a Windows service . This log file captures the same errors as the stdout log file, but without capturing any other processes. |
commons-daemon._service.YYYY-MM-DD.log (where YYYY-MM-DD is the date Yellowfin was started) | appserver>logs | Note: This file is ONLY present if you have installed Yellowfin as a Windows service. This log file logs information relating to the actual Windows service start. |
Catalina.out | appserver>logs | Note: This file is ONLY present if you have installed Yellowfin on a Mac (OS X)/Linux box and you're using the 'Startup (background)' option to start Yellowfin. This log file is NOT created on a Mac/Linux box if you are running Yellowfin via the ‘Startup (terminal)’ option because all info would be logged in the console (as you would see on a Windows box). This log file logs all information relating to the Yellowfin application process; it captures all errors and processes. |
Modifying log files
You can modify what information is logged and how log files are treated — including file size, file management and pattern syntax — via the directory Yellowfin/appserver/webapps/ROOT/WEB-INF/.
Look for one of the following files:
| Yellowfin release | Filename | More info |
|---|---|---|
| Yellowfin 9.4 or later | log4j2.xml | Logging has been upgraded to Log4j2 and works differently in Yellowfin 9.4 and beyond. See https://logging.apache.org/log4j/2.x/index.html for further details. |
| Yellowfin 9.0–9.3 | log4j.properties | Earlier versions of Yellowfin used Log4j logging, which has reached end of life. See http://logging.apache.org/log4j/1.2/ for further details. |
Before making any changes to the file, we recommend that you back up your existing file and place it in a different location.
If you wish to email these files, you may need to stop the Yellowfin service (especially on Windows) as it will either not allow you to send, or send blank files.
Appenders and loggers
Appenders and loggers work together to deliver log events to log files. An appender defines a pattern for each log line, the destination of the line (file, DB, cloud etc.) and any associated configuration. A logger tells Yellowfin what to log and level of logging. A logger also maps Java class files to the appender that the class should use to write its logs. A number of Log4j2 appenders and loggers already exist and are detailed on the log4j2 appenders page.
RepositoryErrorAppender
RepositoryErrorAppender is a custom Log4j2 appender for saving error log messages to the Events table in the Yellowfin repository database.
Error messages having lesser severity such as INFO or DEBUG are not written. However, more severe error messages, such as ERROR or FATAL, are written to the database.
By default, RespositoryErrorAppender is not used.
Use RepositoryErrorAppender — Yellowfin 9.4 and later
To enable the appender:
- Add the appender.
- Associate the appender with the logger category or root category.
within your log4j2.xml file.
1. To add the appender, find the <Appenders> element and add a new line:
<RepositoryErrorAppender name="repos"/>
2. Associate the appender with the logger level or root category in the <Loggers> element. In the example below, we've added the line with "repos" to Root. Root is the default logger. It has no parents and is therefore at the top of the log4j2 logger heirarchy. It therefore logs all error messages from anywhere in Yellowfin's backend to the repository DB.
<Root level="INFO"> <AppenderRef ref="applog"/> <AppenderRef ref="cons" /> <AppenderRef ref="repos" /> </Root>
You can also associate the appender with an entire group of classes. In the example below, we've added the line with "repos" to the class group of com.hof.cluster, which logs all error events from Yellowfin's clustering classes to the repository DB. This is irrespective of the INFO level defined for this category because the code in this particular appender allows only ERROR or higher to be logged.
<Logger name="com.hof.cluster" level="INFO"> <AppenderRef ref="repos" /> </Logger>
Use RepositoryErrorAppender — Yellowfin 9.0–9.3
To enable the appender:
- Add the appender.
- Associate the appender with the logger category or root category.
within your log4j.properties file.
1. To add the appender, add the following line to the log4j.properties file:
log4j.appender.repos=com.hof.adapter.RepositoryErrorAppender
2. Associate the appender with a logging category or the root category of the log4j.properties file. In the example below, we've added "repos" to the following line for rootCategory, so it logs all error messages from anywhere in Yellowfin's backend to the repository DB.
log4j.rootCategory=INFO, cons, applog, repos
You can also associate the appender with an entire group of classes. In the example below, we've added the line with "repos" to the class group of com.hof.cluster, which logs all error events from Yellowfin's clustering classes to the repository DB. This is irrespective of the INFO level defined for this category because the code in this particular appender allows only ERROR or higher to be logged.
log4j.category.com.hof.cluster=INFO, repos
The sourcelog appender
sourcelog is a Log4j appender that logs messages about each source database in their own individual log files.
This appender creates a RollingFileAppender for each source and supports most properties that the RollingFileAppender supports.
The "file" parameter has a %s token, which is automatically replaced with the Yellowfin sourceId.
NOTE: this logger is intended for use by the Yellowfin DBConnectionPool. While the appender may be configured, there is little value in using the appender for any other logger.
By default, the sourcelog appender is enabled.
Locate/modify RepositoryErrorAppender configuration — Yellowfin 9.4 and later
If you wish to modify the sourcelog appender, it can be found in the <Appenders> element area of your log4j2.xml file.
<SourceLog name="sourcelog" fileName="C:/logs/source.%s.log" filePattern="C:/logs/source.%s.log.%i" maxFileSize="1024KB" maxFiles="9">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} %6p: %m%n" />
</SourceLog>
Locate/modify RepositoryErrorAppender configuration — Yellowfin 9.0–9.3
If you wish to alter the sourcelog appender, look for the following lines in your log4j.properties file:
log4j.appender.sourcelog=com.hof.pool.SourceLogAppender
log4j.appender.sourcelog.File=C:/logs/source.%s.log
log4j.appender.sourcelog.MaxFileSize=1024KB
log4j.appender.sourcelog.MaxBackupIndex=9
log4j.appender.sourcelog.layout=org.apache.log4j.PatternLayout
log4j.appender.sourcelog.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %6p: %m%n