This is a sysadmin & developer tool that adds extensive tracing facilities for Drupal hook invocations, database queries and PHP errors.
For an introduction, read the original blog post at:
Some features provided by version 1.0 this module:
- Outputs trace messages to a file or the syslog (on Unix platforms).
- Traces Drupal hook invocations with an optional filter and stack trace.
- Traces PHP warnings and errors with an optional full stack trace.
- Traces SQL database queries with optional filtering by query type.
- Trace output includes microsecond-level timing information.
- Stack traces include the function's passed arguments in PHP syntax.
- Optional debug output includes PHP superglobals and HTTP headers.
- Defines a hook allowing other modules to extend the trace output targets.
Note: this module is primarily intended for use by system administrators and developers, and the available documentation (or lack thereof) reflects that in the set of implicit assumptions it makes. Please post a support request in the module's issue tracker if anything is unclear.