A Fleet of Trucks That Couldn't Fell MPE
July 14, 2015
Out on the HP 3000 newsgroup, Tracy Johnson inquired about the state of the 3000's and MPE's durability. Johnson, who's worked with OpenMPE in the past while managing 3000s for Measurement Specialties, was addressing the Truck Factor for the 3000 and its OS. "In what year did MPE reach the Truck Factor?" he asked, referring to the number of developers who'd have to get hit by a truck before development would be incapacitated.
The Truck Factor is used to measure the durability of open source projects. Results of an industry study show that most open source systems have a small truck factor. Close to half have a Truck Factor of 1, and 28 percent have a Truck Factor of 2. It's measured by looking at software author signatures for code hosted on GitHub in six languages: JavaScript (22 systems), Python (22 systems), Ruby (33 systems), C/C++ (18 systems), Java (21 systems), and PHP (17 systems).
MPE long ago stopped counting the names of such authors. Development ended for the OS when HP retired or reassigned its lab staff during 2009. But the tribal operating and administrative knowledge of the OS has a high truck factor, if you account for global connectivity. Dozens of MPE experts who are known to the community would have to fall under the wheels of trucks for MPE's operational knowledge to expire.
"I honestly don't think it applies any longer to MPE," Art Bahrs commented on the list, "as MPE has now stabilized and has a support base in people like Stan Sieler, Birket Foster, Donna Hofmeister, Neil Armstrong, Alfredo Rego and such. I know I'm forgetting lots more."
One advantage to moving out of the active development phase of life is that a technology becomes stable. It won't acquire new capabilities, and newer technologies will struggle to be relevant in an environment like MPE. But newer wonders like netty, a "client server framework which enables quick and easy development of network applications such as protocol servers and clients," have a TF of 1. If just one developer got taken out by a truck, more than half the GitHub code for netty would be orphaned.
Birket Foster has long used the examples of a rogue bus or a lottery victory to illustrate the delicate state of MPE knowledge at many customer sites. Winning a lottery and immediately retiring, or meeting your end under the wheels of a bus (or truck) could start a local demise of MPE practices. Finding seasoned help to take over in such a tough circumstance would not be impossible. But recovering the knowledge of custom apps will be a challenge for any company who doesn't document crucial applications and practices.
The senior status of MPE among technologies evoked another use of the truck metaphor for Scott Gates. Commenting on the newsgroup, he evoked the history of the 3000 at his school district.
For me, MPE and the HP 3000's "Truck Factor" has been it's like an old pickup truck — you put the key in, turn it over, and it's running. In my four years at Bellefonte, we had one unscheduled downtime when an original system drive failed after almost 10 years of constant use.