On 11/11/05, Michael Krause <[EMAIL PROTECTED]> wrote: > Please clarify the following which was in the document provided by Oracle. > > On page 3 of the RDS document, under the section "RDP Interface", the 2nd > and 3rd paragraphs are state: > > * RDP does not guarantee that a datagram is delivered to the remote > application. > * It is up to the RDP client to deal with datagrams lost due to transport > failure or remote application failure. > > The HCA is still a fault domain with RDS - it does not address flushing data > out of the HCA fault domain, nor does it sound like it ensures that CQE loss > is recoverable. > > I do believe RDS will replay all of the sendmsg's that it believes are > pending, but it has no way to determine if already sent sendmsgs were > actually successfully delivered to the remote application unless it provides > some level of resync of the outstanding sends not completed from an > application's perspective as well as any state updated via RDMA operations > which may occur without an explicit send operation to flush to a known > state. I'm still trying to ascertain whether RDS completely recovers from > HCA failure (assuming there is another HCA / path available) between the two > endnodes.
RDS will replay the sends that are completed in error by the HCA, which typically would happen if the current path fails or the remote node/HCA dies. In case of a catastrophic error on the local HCA, subsequent sends will fail (for a certain time (session_time_wait ) ) as if there was no alternate path available at that time. On getting an error the application should discard any sends unacknowledged by it's peer and take corrective action. After the time_wait is over, subsequent sends will initiate a brand new connection which could use the alternate HCA ( if the path is available). > > Mike > > _______________________________________________ > openib-general mailing list > [email protected] > http://openib.org/mailman/listinfo/openib-general > > To unsubscribe, please visit > http://openib.org/mailman/listinfo/openib-general > > _______________________________________________ openib-general mailing list [email protected] http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
