Performance, Rpm performance, 4 performance – HP Integrity NonStop H-Series User Manual
Page 17
HP NonStop
RPM User’s Guide Page 17 of 52
1.4 Performance
RPM was designed to provide a fast lightweight means of determining the busiest processes and processors in
collections of NonStop servers.
Additionally unlike some performance monitors, RPM monitors processes without requiring any disk I/O at all. The
result is that RPM has extremely low-overhead and very low-response-time at start-up.
RPM also provides super-scalability, meaning it can monitor from 1 processor, up to 4000+ processors in a linearly
scalable manner without causing any performance degradation or processor "hot spots". Thus RPM can monitor
many millions of processes, quickly determining which processes are the busiest and providing displays such as
the ones shown in this manual.
Since RPM is a memory based monitor and does not cause any disk I/O, RPM provides the fastest possible way to
determine the busiest processes and processors on your NonStop servers.
Beginning with RPM release 1.2 the notion of "busiest process" was significantly extended from the basic notion of
only being able to discover processes that consume the most Cpu cycles. RPM now provides a more refined
notion of being able to discover "busiest" processes based on a wide-range of process selection and analysis
criteria as discussed for BY item options in the
As a result of new BY item capabilities in RPM, it was possible to discover detailed performance issues and to
engineer significant performance improvements into the RPM 1.2 release.
RPM 1.2 performance was improved so that RPM processor overhead was REDUCED 10-20x, and RPM 1.2
messaging overhead was REDUCED by more than 100x over prior versions of RPM.
Interestingly these RPM performance enhancements were the result of RPM being able to analyze itself in real-
time. Likewise it should be possible in many cases to utilitze RPM features to gain a greater understanding of real-
time application and system performance using this low-cost tool.