3.4. General Run-Time Support Notes
The PMIx installation must be in your
PATH
on all nodes (and potentiallyLD_LIBRARY_PATH
orDYLD_LIBRARY_PATH
, iflibpmix
is a shared library).PMIx’s run-time behavior can be customized via Modular Component Architecture (MCA) parameters (see the MCA section for more information on how to get/set MCA parameter values).
If specified, we recommend that the
ptl_tcp_if_include
parameter include the loopback device (lo
on many Linux platforms) to ensure that at least one intra-node transport can be found between a local client and its server. For example:export PMIX_MCA_ptl_tcp_if_include lo,eth1 ...
Running on nodes with different endian and/or different datatype sizes within a single PMIx-based application is supported in this release, at least from a PMIx perspective (i.e., we will pack/unpack to handle the situation). However, PMIx does not resize data when the same datatype differs in size (for example, sending a 4 byte
double
and receiving an 8 bytedouble
will fail).