[ofa-general] general questions about librdmacm

[Steven Dake]

Developers,

I am a maintainer of a project called openais/corosync (www.openais.org)
which implements a network protocol called Totem.  This code is the
basis for much of the community work on clustering in Linux and other
platforms.  I don't yet have hardware, but will shortly and intend to
add OFED RDMA support to the base Totem protocol used for our
communications.

Totem is a reliable virtual synchrony multicast protocol which transmits
a message from any node to all nodes in a collection of computers
(called the configuration or membership).  It has a few requirements:

unreliable datagram multicast
unreliable datagram unicast
ability to bind to a specific port and interface
ability to poll() (POLLIN) via system call for new multicast datagram
messages

Today Totem is based upon IP(v4 or v6 are supported) and uses UDP.

Few questions:
1)  I would like to continue to use IP addressing but it looks like I
have to use a different addressing model in librdmacm.  I looked at the
examples in the library and it isn't clear to me whether they use IP
addressing or some other addressing model.  I see references to IPoverIB
but I don't see any information in the wiki on the topic.  Anyone have
links to documentation on the topic of node addressing?

2)  The library doesn't have any non blocking (kernel wait queue based)
polling mechanism that I can see.  Am I missing a call here?

3)  Of course using the standard socket API would be highly desired as
it requires less code changes.  Is there some other library I should be
using?

Regards
-steve