6.3.6. Instance parameters — logging

Instance parameters can be set on the tabs of the Edit Instance Parameters window. The Logging tab has the following parameters:

Instance parameters — logging

Figure 6.20. Instance parameters — logging

  • Verbosity level: It is the general verbosity of the instance. It ranges from 0 to 9; the higher value means more detailed logging.

    Note

    Setting a high verbosity level (above 6) can dramatically decrease the performance. On level 9 Zorp logs the entire passing traffic.

    Tip

    The default verbosity level is 3, which logs every connection, error and violation without many details.

    Level 4 to 6 include protocol-specific information as well.

    Levels 7 to 9 are recommended only for troubleshooting and debugging purposes.

  • Message filter expression: It sets the verbosity level on a per-category basis. Each log message has an assigned multi-level category, where levels are separated by a dot. For example, HTTP requests are logged under http.request. A log specification consists of a wildcard matching log category, a colon, and a number specifying the verbosity level of that given category. Separate log specifications with a comma. Categories match from left to right. For example, http.*:5,core:3. The last matching entry will be used as the verbosity of the given category. If no match is found the default verbosity is used.

  • Include message tags: It prepends a log category and a log level to each message.

  • Escape binary characters in log files: It replaces non-printable characters with XX to avoid binary log files, also characters with codes lower than 0x20 or higher than 0x7F.

Note

Customized logging can be very useful, but should be used with caution. Too many log specifications can decrease the overall performance of Zorp.

Example 6.4. Customized logging for HTTP accounting

The HTTP proxy logs accounting information into the accounting category. Requested URLs are logged on level 4. To log the URLs, but leave the general verbosity level on 3, add a new log specification to the Message filter expression list: http.accounting:4.