System Administration - eXist: A NoSQL Database and Application Development Platform - page 386

Level Description

Warn Used for reporting unexpected or nonoptimal behavior that is noncritical; that is, your operation or query will most

likely still perform correctly.

Error Used for reporting errors while performing a database or query operation. These messages indicate that something

failed and the user or system administrator may need to take action.

Fatal Used for reporting critical failures within eXist. Rarely used in eXist, but can report a corruption in the database or an

index.

Levels in log4j are inherited upward, meaning that logging at the most fine-grained
Trace level will log all message levels (i.e., also the Debug, Info, Warn, Error, and
Fatal levels); likewise, logging at the Info level would actually log messages from the
Info, Warn, Error, and Fatal levels.

In eXist the log4j configuration file is $EXIST_HOME/log4j.xml , and it is configured
to log at the Info level by default. If you wish to adjust this, you can change the prior‐
ity levels in the log4j configuration file as follows:

<root>
<priority value= "debug" />
<appender-ref ref= "exist.core" />
</root>
Log4j allows you to direct log messages from different parts of the database to
different receivers. By default, in eXist all of the receivers are files, and the logfiles are
written into the directory $EXIST_HOME/webapp/WEB-INF/logs . See Table 15-2 .

Table 15-2. eXist logfiles

Logfile Description

exist.log The main logfile of eXist; all messages that are not directed to any of the other logfiles end up here. It

contains details of the database server, the database and index status and health, and XQuery execution.

xacml.log The logfile for the XACML (eXtensible Access Control Markup Language) engine in eXist. XACML support in

eXist is deprecated.

xmldb.log The logfile for XML:DB API operations; typically these log messages also appear in exist.log .

urlrewrite.log The logfile for the XQuery URL rewriting engine. When you are developing XQuery apps that use URL

rewriting, it can be useful to study both exist.log and this file when you have issues.

profile.log If you switch on XQuery profiling using util:enable-profiling or the profiling pragma, the results of

the profiling can be logged to this file at the Trace level. This approach is deprecated in favor of the profiling
tool in the Admin Web Application (see “Checking Index Usage” on page 282 ).

scheduler.log This file logs messages related to scheduled tasks in eXist. These include the database flush-to-disk tasks and

also your own XQuery or Java scheduled jobs. If you are having trouble running your own scheduled jobs, this
is the place to look for feedback.