This article 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.


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

If BaseX is used in a Web Application, all trace output (generated via fn:trace, prof:time 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 LOG option.
  • The maximum length of logging messages can be changed via LOGMSGMAXLEN.
  • The Admin Functions provide access to the log files from XQuery.

If a proxy is used, the original IP address of the client will be added to the logs.


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 request:set-attribute 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 session:set (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.


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

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

Example 2
01:23:33.251   john   OK        QUERY[0] 'hi'   0.44 ms
01:23:33.337   john   OK        ITER[0]         1.14 ms
01:23:33.338   john   OK        INFO[0]         0.36 ms
01:23:33.339   john   OK        CLOSE[0]        0.21 ms
01:23:33.359   john   REQUEST   EXIT
01:23:33.359   john   OK                        0.14 ms

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

Example 3
01:31:51.888   admin   REQUEST   [GET] http://localhost/rest/factbook
01:31:51.892   admin   200                                              4.43 ms

An admin user has accessed the factbook database via REST.


Version 9.5
  • Updated: Show IP address behind proxy.
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 LOGPATH option.
  • Updated: Include session attributes in log data.

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