Does anyone reading this have experience with debugging ORA-12157 TNS Internal network communication error?
Googling for it isn't really helpful. I get a bunch of pages that say the same thing as the Oracle docs (turn on tracing and reproduce the issue).
The problem is that we don't see it consistently enough to even know to reproduce it properly much less create a minimal test case.
I looked in the alert.log and found a few "ORA-609 : opiodr aborting process unknown ospid" errors each with a corresponding trace file that ends with "opiino: Attach failed due to ORA-12537".