Changing OSWatcher User
Tracing TFA to find out how to change user under under which OSWatcher ist started. Continue Reading
eBPF
Troubleshooting TFA Start
A server crash can prevent a correct TFA start. Continue Reading
Kernel Memory Leak due to ACFS Snapshots
The case study of troubleshooting a serious kernel memory leak issue caused by a failed ACFS snapshot deletion. Continue Reading
WINDOW SORT PUSHED RANK Performance Regression in Oracle 21c
New optimization causing severe performance degradation. It can be switched off with the fix control. Continue Reading
Workaround for Non-Functioning uretprobes with Oracle Database Software
Oracle database software breaks uprobes and uretprobes. The workaround for uprobes is well known – adding an offset to the function entry. This article explains how to emulate uretprobes with uprobes as a workaround. Continue Reading
killsnoop Limitation
The current implementation of the eBPF bcc tool killsnoop doesn’t capture signals sent by the tgkill() system call. Continue Reading
oradebug request completion
Exploring the internals of the undocumented Oracle wait event “oradebug request completion” with eBPF. An example of an off-CPU analysis. Continue Reading
Perilous New Undocumented Tracing Feature in Oracle 21c
Database writer performance impaired by sudden debug trace. Continue Reading