Compliance and Interoperability Discussion 11/25/2014 Paul Grun

C & I Already agreed on several criteria leading up to a release: –Provider existence proof, test cases, man pages… Should we also include either compliance or interoperability testing –Either as part of the release process or as an adjunct to it Should the OFA provide a C&I service for libfabrics implementations? ISC

Compliance Compliance: An implementation is said to be compliant with a set of requirements if it conforms to those requirements through some measurable objective criteria Important point: “Compliance of what, with respect to what?” Typically, requirements are stated in formal language as part of a specification –There is no formal libfabrics specification ISC

Application hardware consumer provider In terms of classical layering… Application hardware consumer provider - Any given layer has a vertical interface to the layers above it and below it. - Peer layers communicate with each other via a protocol. protocol interface

Application hardware consumer provider Compliance, Interoperability Application hardware consumer provider Technically: Interoperability describes how accurately two peers exchange a well-defined protocol. Compliance describes how well a given layer conforms to an interface specification.

Application hardware consumer provider Compliance, Interoperability Application hardware consumer provider For our purposes, roughly: Interoperability is the horizontal relationship between peer layers, Compliance is the vertical relationship between adjacent layers. interop compliance

Application hardware consumer provider Application layer Application hardware consumer provider Interoperability among instances of an application is defined solely by the...application. Similarly, the interface to the consumer is defined by a combination of the consumer and the application. Both are outside the scope of the OFA.

Application hardware consumer provider Consumer layer Application hardware consumer provider The consumer protocol is defined by…somebody else (OpenMPI, MPICH…). Outside the scope of the OFA. But the consumer/provider interface is defined by us (OFI WG). Very much in scope for the OFA. Should the OFA define a compliance test for OFI WG consumers?

Application hardware consumer provider Provider layer Application hardware consumer provider As above, the consumer/provider interface is defined by OFI WG. Should the OFA define a compliance test for OFI providers? Not clear! What about the end-to-end provider protocol? Again, not clear.

Application hardware consumer provider Hardware layer Application hardware consumer provider Interoperability on the wire is defined by an industry standard – ENET, FCOE, IB…Clearly out of scope for the OFA. Likewise, the provider/hardware interface is the province of somebody else.

Application hardware MPI OFI provider Example: MPI Application hardware MPI OFI provider defined by MPI The MPI on-the-wire protocol is defined by somebody like OpenMPI, MPICH, etc… The application interface is similarly defined by somebody else. In both cases, this is outside the scope of the OFA

Application hardware MPI OFI provider Example: MPI Application hardware MPI OFI provider libfabrics API defined by MPI defined by OFA But the interface to the OFI provider is defined by the OFA – OFI

Application hardware MPI OFI provider Example: MPI Application hardware MPI OFI provider libfabrics API As an industry service, the OFA could provide: 1.Compliance testing of the MPI implementation to the OFI-defined APIs but not the MPI on-the-wire protocol 2.Compliance testing of the provider implementation to the OFI-defined APIs

Application hardware MPI OFI provider Example: MPI Application hardware MPI OFI provider libfabrics API As an industry service, the OFA could provide: 1.Compliance testing of the MPI implementation to the OFI-defined APIs but not the MPI on-the-wire protocol 2.Compliance testing of the provider implementation to the OFI-defined APIs 3.Protocol testing of provider layer on-the-wire protocols

Discussion ISC 2013