March, 2003 SOS 7 Jim Harrell Unlimited Scale Inc.

The Good The Bad The Future

Good things are unimportant. Bad things should be fixed. The Future is what you make of it. Ron asked for Opinions…

Introduction Everything begins and ends with the hardware and applications System Software is just glue – it is nothing by itself –My background System Software projects all the hardware capabilities to applications in a easy to use well understood fashion –System Services – HSM, etc. must be out of the way… –Systems have to be up to be used –One system is better than 10 thousand

Good Processors are cheap and fast –Peak speeds are like gas mileage projections –Hot – and poorly cooled –Complex – additions not always useful –Driven out specialized processors and software –Fewer choices – used to be more processors than companies… Memory is cheap –Larger memory is traded off for expensive and fast Interconnects exist –Just implemented as I/O devices I/O channel speeds are as fast as HPC systems 10 years ago –More than 10x cheaper –Striping data can extend across nodes

The Good Unix is the OS of choice –20+ years of dominating delivered systems in HPTC –Software system research is irrelevant – (Rob Pike) –Linux is Unix Recognizable at source level Only Unix for IA32 Java is programming MPPs are gone –Commodity pressure on engineering costs –Late generation MPPs had single process space and single filename space – this should be salvaged We have clusters –This is good – expect small smps for the foreseeable future Multi-threading is hard and all components have to be threaded..

The Bad Operating System development and checkout should not be done in public –New systems and larger systems always provide surprises –Onsite integration of what ought to be compatible equipment is often hard to do.. –Traditionally large systems need to be shipped and require some work onsite

The Bad I/O and filesystems don’t work well enough –MPP model of data delivery requires high speed interconnect –Years of MPPs have reduced the expectations for I/O performance Expectations appear to be for large sequential I/O –Clusters have to share data using software – this becomes a difficult filesystem issue –Need global filename spaces and reasonable performance Cluster filesystems may be only part of the answer. Quorum is a Latin word. Latin is a dead language.

The Bad Complexity … –The level of complexity is too high for applications MPI has a high learning curve and looks like a protocol –Specialization and growth can create distance -

The Future Heterogeneous processors – in a single system –Use processors for the work suited to the capabilities –Apply specialized cpus, PIMM, FPGA, etc. to application work –Support with commodity processors Interconnects built as interconnects - not I/O devices Distributed system software instead of cluster service software –Single systems – single process space, global resource management, and single filename space systems CoArray Fortran, upc, etc. – move towards integrating parallelism in programming environments Cycle of commodity dominance has not peaked – but will