Conference futurs::sybase

507.0. "UCX vs DECnet performance (INETDRIVER, SYBASE appli)?" by PRSSOS::DIETZ (Pierre-Etienne DIETZ, Support/France) Fri Mar 28 1997 18:02

Problem: A SYBASE application, on an ALPHA 2100A, is running at 
         least 4 to 10 times slower with UCX than with DECnet.      
         (It's being ported from a RDB application on a VAX 7000).
         *** cross-posted in LASSIE::UCX and in ORAREP::NOMAHS::SQL ***
In example:
          +------------------------------------------+   Client transactions:
Config :  !  DataBase Server          Cobol Client <---- Reads 4500 lines
--------  !  SYBASE V11.0.2                 !        !        from a file
          !         !    <- SRI QIO$ ->     !        !  => 4 to 5 SQL requests
          !     INETDRIVER             INETDRIVER    !        by line
          !         !                       !        !  => ~20000 requests
          !         !----<--        --->----!        !
          !                 UCX V4.1                 !
          !                 VMS 6.2                  !
          !         Alpha 2100A Biprocessor          !
          +------------------------------------------+
  Performance figures:                         Batch Elapsed Time:
              DECnet => ~10 SQL requests /sec (completion in  5 minutes)
              UCX    => ~0.5 SQL request /sec (completion in 60 minutes)!!!
                                                             ===========
- Tests also run on a similar configuration, with similar results:
    SYBASE V10.0.2
    UCX V4.0 ECO 3
    AS 2100A  

Analysis : the following has been checked:
---------

o  The client process is running ...
    (If UCX)    50% of its time in Kernel Mode (pretty high)
    (if DECnet) 25% of its time in Kernel Mode (~normal)
o  UCX proto TCP quota increase (4K -> 32K) does not improve the link.
o  No MBUF Waits or Drops.
o  No Device_socket "SEND" Buffer or I/O waits 

Questions:
---------
- INETDRIVER Setup: Yet the QIOs done on the INETDRIVER have to be run 
    a second time on the BGDRIVER, is there some tuning available?
- Kernel Mode activity: Is that level of Kernel Mode reduceable? 
- Any other reference of such an application with good performances, 
    in order to compare with that one?

Thanks a lot for any advice, best regards
Pierre-Etienne