Latch acquisition/release call-graph : Dynamic tracing tools in action

In an oracle database, it’s very common for a process to hold multiple latch at different level in different mode (shared/exclusive) concurrently. The question is : Is it  possible to draw a call graph to track the different step of acquisition and release for a particular process ?

perf_events : Off/On/Mixed CPU flamegraph extended with oracle wait events

Using  FlameGaphs  for investigating performance problem can be a valuable asset for quick resolution and identification of the root cause. This type of analysis may be needed when the traditional oracle instrumentation are not enough.

This post is based and inspired by the awesome work of Brendan Gregg ,Luca Canali and Frits Hoogland in this area. Please check the references at the end of the post for more info (Worth reading !)

What i will cover here is a tiny script i written for generating 3 types of extended flamegaph using the build in perf tool. I said extend because they actually include the oracle wait events.

• Off cpu
• On cpu
• HOT/COLD flame graph