Re: Oracle MVS CPU Utilization Nightmare
Date: 1996/10/03
Message-ID: <5307u4$93b_at_news00.btx.dtag.de>#1/1
Jim Ford <Jim_Ford_at_mgic.com> wrote:
>We are running Oracle for MVS, 7.2.3, but use it strictly as a mechanism
>to access our Unix instances of Oracle. For example, a CICS program will
>connect to Oracle/MVS, which then uses SQL*Net (2.2.3) and IBM's version
>of TCP/IP for MVS (V3) to route the request to a remote instance of
>Oracle on our AIX boxes. There are no Oracle instances on MVS.
>While our applications work, we are paying a terribly heavy price for it
>in CPU consumption. We have a three processor Amdahl box, and Oracle,
>SQL*Net and TCP/IP are by far the largest consumers of CPU on it, to the
>point where little else is getting done. We are pumping a lot of
>transactions through (I don't have the exact numbers, but can get them),
>but this still seems irrational to me. The three MVS address spaces are
>basically doing not much more than routing the work to Unix. To my way
>of thinking, we are paying a lot and getting a little. I can contrast
>this to the DB2 work that is going on at the same time. It uses quite a
>bit less CPU than Oracle is using, and DB2 is actually managing data
>bases on MVS, not sending work somewhere else to be done.
>Management is reluctant to upgrade the mainframe; moving work to Unix
>was supposed to reduce mainframe usage, not lead to upgrades. Also, it
>seems likely that there's enough latent demand that we'll expand to use
>up whatever we upgrade to, anyway.
>I am not an Oracle DBA (my background is DB2), so I hope what's here
>makes sense. Oracle says that things are working as designed, but I
>don't buy it. We're in a pickle, and I hope someone can help.
I am not familar with this setup in real life, but was faced with a similar question from a customer.
We came to a different solution: CICS will be installed on the AIX side, and the CICS-requests will then be routed to the AIX box which performs the actual SQL-Connection.
Also, I think this way you are able to use SNA, which at this time is much more CPU-friendly to MVS than TCP/IP...
What you are doing now is Client/server, the MVS in the role of the client. If you have many transactions, then you surely have a lot of communication, which will be CPU intensive.
You should also take a look at your application. If the application sends 10 simple requests to the DB to display a simple screen, then the two systems must communicate 10 times with each other. If your application does complex queries with many joins or full-table scans, then the communication overhead will be less compared to the DB-load, and you actually can offload work from your mainframe.
Willy Klotz
Willy Klotz
Willys Mail FidoNet 2:2474/117 2:2474/118 Mailbox: analog 06297 95035 ISDN 06297 910105 Internet: willyk_at_t-online.de -> No Request from 06.00 to 08.00 <- ======================================================================Received on Thu Oct 03 1996 - 00:00:00 CEST