README

This directory contains SystemTap scripts for userspace probing of Oracle database processes, originally developed for Oracle troubleshooting and investigations of Oracle internals.

Author: Luca.Canali@cern.ch
First release: September 2014

Relevant blog posts:
http://externaltable.blogspot.com/2014/11/life-of-oracle-io-tracing-logical-and.html
http://externaltable.blogspot.com/2014/09/systemtap-into-oracle-for-fun-and-profit.html
http://externaltable.blogspot.com/2016/03/systemtap-guru-mode-and-oracle-sql.html

Acknowledgments: 
  @FritsHoogland for original work and collaboration on Oracle userspace tracing.

Compatibility and notes:
   The userspace-trace scripts require Linux UTRACE or UPROBES. 
   This is the case of RHEL/CentOS/Oracle Linux 6.x (UTRACE)and 7.x (UPROBES)
   These scripts will not work with old kernels such as RHEL 5.
   SystemTap 2.5 or higher is needed.

Notable exception and issues with Uprobes and Oracle 12c
   When using UPROBES to trace Oracle 12c the scripts will throw "inode-offset registration error"
   Oracle 11g is not affected by this issue
   This issue is relevant for RHEL/OL version 7.1 or higher
   @Hatem__Mahmoud has describes this issue in details and proposes a workaround at:
   https://mahmoudhatem.wordpress.com/2017/03/27/workaround-for-systemtap-issue-oracle-tracing-registration-error-rc-0
   Another workaround is to use an older version of Linux kernel (kernel 3.10.0-123.x or older) 
   
The installation of Kernel debuginfo is needed for several of the scripts that also have OS probes. See details on the scripts' headers.