Lon Hohberger wrote: > On Thu, 2005-06-23 at 11:23 -0400, Olivier Crete wrote: > > >>>If you use CMAN's service manager, you will be able to tell if the app >>>has crashed (all nodes in that service group will be notified of the >>>state change). >> >>In the RHEL4 branch there does not seem to be a userspace API for the >>Service manager.. apart from the ioctl and libmagma. Is libmagma your >>long term api ? Also, can libmagma be used in non-GPL apps? I saw some >>scary comments in magmamsg.h... > > > Correct. > > libmagma is LGPL. The theory is that you could write any app and link > it dynamically against it. Furthermore, the idea was that, on the > back-end, you could make it load a non-Free plugin to talk to a non-Free > cluster infrastructure. > > libmagmamsg is GPL, due to having code chunks from an older GPL project. > The code is quite awful, but it works. I hope it gets replaced with an > nice cluster-agnostic message system at some point which can be used for > more than just cluster stuff. > > >>>Internal deadlocks are harder to detect from the cluster infrastructure >>>perspective. I'd consider using the kernel watchdog timer. >> >>An easy way would be to have a cluster watchdog (ie.. the app must >>"ping" the cman daemon at least one in X seconds and if it isnt its >>considered deadlocked..) > > > As it stands now, kernel-mode cman doesn't have this kind of capability. > I could be mistaken, of course. cman manages nodes, not applications. -- patrick -- Linux-cluster@xxxxxxxxxx http://www.redhat.com/mailman/listinfo/linux-cluster
