HP provides IMAGE deadlock detection in PowerPatch 6

As HP readied the latest PowerPatch 7 of MPE/iX 5.5, a database expert pointed out a new feature of IMAGE/SQL just available in the prior PowerPatch 6 to reduce database deadlocks.

Mike Hornsby of Beechglen Development noted that “HP apparently added and enabled automatic deadlock detection for IMAGE/SQL databases. Up until this point it was especially easy to create a ‘deadly embrace’ that would usually result in the need for an HP 3000 reboot. In recent versions there have been some ‘undeadlock’ utilities, but this method is far superior.”

Although careful programming can eliminate the prospect of deadlocks, Hornsby points out that applications with a long history of development and use at a site sometimes aren’t coded that way — which makes the deadlock detection valuable.

“On larger systems with software that has been developed over decades by a cast of many programmers, deadlocks occasionally occur,” Hornsby said. “Rebooting the system is a major problem, and back-tracking the events to fix the problem is very time-consuming. This usually is viewed by the users as a reason for dumping this ‘legacy’ system and going with something new.

“The big deal is that HP has finally fixed one of the original bugs in IMAGE — any programmer that can give MR to a program could deadlock the database. And the bigger deal is that they made the switch happen automatically.”