Logging

This article is part of the Advanced User's Guide. It describes how client operations are logged by the server. The server logs can e.g. be used to get an overview of all processes executed on your server, trace any errors or compile performance statistics.

Introduction
The server logs are written in plain text. In your Database Directory, you can find a folder named  in which all log files are stored with the according date. Note that, depending on your OS and configuration, files and folders beinning with a  may be hidden. The log directory can be changed via the option.

If BaseX is running as Web Application, all trace output (generated via fn:trace, $$ and similar functions) will be stored in the logs as well.

Some more notes on the logging facility:


 * HTTP requests are included in the log files.
 * Logging can be turned on/off via the option.
 * The maximum length of logging messages can be changed via.
 * The Admin Module provides access to the log files from XQuery.

RESTXQ
The request attributes will be checked for a user id.

By default, RESTXQ code is executed with the admin user. As a result, this user will be displayed in the logs for all RESTXQ requests. In a web application with a custom user management, however, the name of the actual user who has sent a request is often more relevant.

When log data is written during the processing of a RESTXQ function, the following is looked up as follows:


 * 1) The current request is checked for an id attribute. The attribute can be assigned via RESTXQ and the $$ function, and it is the recommended approach for stateless requests as all request attributes will be dropped after the finalization of a request.
 * 2) If none is found, the id attribute is looked up in the current user session. The attribute can be assigned via $$ (see e. g. the DBA code for sessions and user handling). If the request path contains a dba segment, a dba session attribute will be looked up instead.
 * 3) If none is found, the default path will be taken, and the user of the current database context will be included in the logs.

Format

 * Example 1:

01:18:12.892  SERVER           admin   OK        Server was started (port: 1984) 01:18:15.436  127.0.0.1:4722   jack    REQUEST   XQUERY for $i in 1 to 5 return random:double 01:18:15.446  127.0.0.1:4722   jack    OK        Query executed in 2.38 ms.                       2.72 ms 01:18:15.447   127.0.0.1:4722   jack    REQUEST   EXIT 01:18:15.447  127.0.0.1:4722   jack    OK                                                         0.39 ms

A server has been started and a user  has connected to the server to perform a query and exit properly.


 * Example 2:

01:23:33.251  127.0.0.1:4736   john   OK        QUERY[0] 'hi'   0.44 ms 01:23:33.337   127.0.0.1:4736   john   OK        ITER[0]         1.14 ms 01:23:33.338   127.0.0.1:4736   john   OK        INFO[0]         0.36 ms 01:23:33.339   127.0.0.1:4736   john   OK        CLOSE[0]        0.21 ms 01:23:33.359   127.0.0.1:4736   john   REQUEST   EXIT 01:23:33.359  127.0.0.1:4736   john   OK                        0.14 ms

A user  has performed an iterative query, using one of the client APIs.


 * Example 3:

01:31:51.888  127.0.0.1:4803   admin   REQUEST   [GET] http://localhost:8984/rest/factbook 01:31:51.892  127.0.0.1:4803   admin   200                                                   4.43 ms

An admin user has accessed the  database via REST.

=Changelog=


 * Version 9.3
 * Updated: Store trace output in database logs
 * Updated: RESTXQ: The request attributes will be checked for a user id.


 * Version 8.6
 * Added: The log directory can be changed with the option.
 * Updated: Include session attributes in log data.