Single System Image?
#1
My five boards arrived yesterday and, of course, I want to cluster them together. I have a program to run which is multithreaded but not parallel across processors (that I know of.)

There once was Kerrighed and OpenSSI, both of which could present the cluster to the user/software as a single system image and hand the transport and messaging layer invisibly. Kerrighed hasn't been active since kernel 2.x and OpenSSI was last updated six or seven years ago.

Is there still a way to create a single system image type cluster?
  Reply
#2
most articles i've read on cluster sbc mention using spark which uses master/slave type setup. but it's not a single image. i would think each board needs an image.
  Reply
#3
Right, each board needs it's own image - at least until we figure out a way to diskless boot them - but there's software that handles message passing and load balancing so the user/software sees a, for example, 20-core processor instead of 5x 4-core processors. That's what Kerrighed and OpenSSI did but, since the projects have lain abandoned for years, I assume something better or easier to maintain has come along. I just can't find it. Maybe my Google-fu is weak.
  Reply
#4
(02-18-2017, 11:34 AM)Paraplegic Racehorse Wrote: Right, each board needs it's own image - at least until we figure out a way to diskless boot them - but there's software that handles message passing and load balancing so the user/software sees a, for example, 20-core processor instead of 5x 4-core processors. That's what Kerrighed and OpenSSI did but, since the projects have lain abandoned for years, I assume something better or easier to maintain has come along. I just can't find it. Maybe my Google-fu is weak.
setup cluster on rpi  gave some useful links.
  Reply
#5
Yep. Those are all pretty useful, but it's all either High Availability (failover), instead of High Perfomance (parallel processing), and all the HPC stuff is based on code requiring parallel API calles (mpich, etc.) instead of Single System Image setups. Beowulf, for example, is parallel but not SSI. The software still sees each node as a separate node. The idea behind Single System Image is none of the HP stuff needs new API calls written into the software. Unmodified multi-threaded applications see the whole cluster as a single system, rather than a cluster of nodes, and can just use it as such.

Maybe there's something already built into the kernel to handle this? Kerrighed was a stack of kernel loadable modules and config files. I'm not quite sure how OpenSSI worked. The setup instructions are lacking, to be generous.
  Reply
#6
this seems to be the latest incarnation, not sure if it is still active. but it came out of openMOSIX, i read.
http://linuxpmi.org/trac/
however,
Is LinuxPMI SSI(single system image) software?
A: No. LinuxPMI is multi-system-image software. it looks like SSI, but from the perspective of *each* *node*. LinuxPMI can work in clusters with a diverse choice in linux distributions, libraries, etc. the only thing that must remain the same are CPU types, and some OS kernel features
  Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)