On Mar 05, 2007 14:22 +0100, Donadini Thibault wrote: > Since the last documentation, OST_IO_PORTAL has been created and has > replaced OST_REQUEST_PORTAL 6, which became OST_REQUEST_PORTAL 28. > > What is the purpose of OST_IO_PORTAL ? > How does it work ? ( opcodes associated, ...., how many buffers.. with > which information, etc..) > > What is the new purpose of OST_REQUEST_PORTAL ?
The reason for this change is that small/fast RPC requests like getattr were being blocked behind many GB of IO RPCs and this was causing responsiveness problems. For reasons of compatibility, the service threads running on portal #6 were kept for doing the large IO requests (because they have pre-allocated 1MB buffers for doing IO without allocations). The small request RPCs were moved to a new portal (#28) if both the client and server understand the OBD_CONNECT_REQPORTAL feature. Both services handle the same RPC requests over the wire. The same is true for the MDS_*_PORTAL - the format of the requests and the back-end handling code is exactly the same, but they are split into different portals because of latency or deadlock-avoidance issues. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. _______________________________________________ Lustre-discuss mailing list [email protected] https://mail.clusterfs.com/mailman/listinfo/lustre-discuss
