Re: better understanding rdma-cm UNREACHABLE/ETIMEDOUT scheme

[Alex Rosenbaum <alexr-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>]

On 5/21/2013 6:24 PM, Hefty, Sean wrote:
> My first guess is that the server isn't responding to new requests. - 
> Sean 

This is where we're looking now.
Now testing on 17 server with 8 clients per server.

When disabling all RDMA traffic in the test we get 100% RDMA connection 
established. So at least we know this is not some fundamental issue with 
our setup.

Modifying our code to increasing the priority of RDMA connection 
handling to be higher then the RDMA traffic (CQ completions handling) we 
still see many UNREACHABLE events. But only after quite a few client got 
connected and started pushing traffic (1GB RDMA WRITEs from server to 
client).

We are now adding code (via the conn_attr private data) to compare 
timestamp between the rdma_conenct, RDMA_CM_EV_CONNECT_REQ, rdma_accept 
and on the client events of UNREACHABLE or CONNECTED.
We'll have better understand once we see these results.

thanks,

Alex
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