Before the cloud solution era, TPC-C online transaction processing benchmarks were dominated by Oracle-based solutions using Oracle Tuxedo as the TP monitor. Many TPC-C reports include the Tuxedo application code and Oracle Tuxedo is still powering our financial institutions, telecom, and many other companies.

In this talk, I will focus on the UNIX APIs that have made the Tuxedo messaging core tick since the early 1980s: System V IPC message queues.

I will start with an overview of an early and simple implementation from PDP-11 days and end up with a modern Linux implementation and some important performance tricks. I will show how eBPF tools can be used to gain more insight and collect metrics beyond the standard ones.

Next, we will look at how Tuxedo uses the API to implement the request-reply pattern, overcome message size limits to send large messages, improve scalability, add timeouts for blocking API calls, and finally communicate with other machines invisible to the developer.