Poor Oracle performance with load CPU load

hi,

   we run oracle8.1.7 on HP-UX 11i.

   The DB performance becomes very poor that a lot data is lost for application processing queue overflow.

          Application  ---- >     DB
                ^
                |
         data queue here

   I noticed that CPU load of db server is not high, but the top5 process change from DB main process 'oraclecodb' to ora_lgwr_codb, ora_dbw1_codb, ora_dbw2_codb, ora_dbw3_codb , ora_dbw0_codb .

   with sar -d 5 1000, it shows some disk is very busy

     23:56:55   c0t6d0    3.61    0.50       6      35    0.00   11.36
           c4t6d0    3.61    0.50       5      33    0.00   10.57
         c11t12d1   38.68    1.33      96     776    4.47   11.48
         c11t12d7   32.87    1.11      90     728    3.13   10.23
         c11t13d5   32.87    2.04     104     842    7.59   10.18
         c11t14d3   37.68    1.99     108     922    7.30   10.83
         c11t15d1   34.07    1.84      96     781    7.22   10.89
         c11t15d7   37.27    1.63     101     830    5.48   10.78
          c12t0d5   31.66    1.42      97     774    4.98   10.37
          c12t1d3   29.66    1.59      99     806    5.68   10.16
           c9t2d1   35.07    1.19      93     745    4.22   11.78
           c9t2d6   38.88    1.88     101     837    7.30   11.82
           c9t2d7   35.27    1.40     100     798    5.45   12.05
           c9t3d5   40.68    1.50     104     837    5.85   11.90
           c9t4d3   40.68    1.78     103     826    7.26   13.19
           c9t5d1   36.07    1.27      96     765    4.57   11.56
           c9t5d7   34.47    1.02      97     774    3.00   11.49
           c9t6d5   37.27    1.21      96     766    4.46   11.80
         c11t12d2   14.23    0.50      24     192    0.00    9.06
         c11t13d0   18.64    0.63      30     239    1.14   14.30
         c11t13d6   19.64    0.50      29     231    0.00   12.33
         c11t14d4   17.84    0.50      27     218    0.07   11.78
         c11t15d2   18.24    0.50      28     221    0.00   10.66
          c12t0d0   16.43    0.50      27     216    0.15   12.48
          c12t0d6   18.24    0.50      29     232    0.00   11.44
          c12t1d4   15.03    0.50      28     223    0.00   10.08
           c9t2d2   18.64    0.52      29     236    0.33   13.11
           c9t3d0   20.04    0.56      32     258    0.55   13.47
           c9t3d4   16.43    0.50      26     212    0.00   12.69
           c9t3d6   21.24    0.50      35     277    0.02   14.18
           c9t4d4   20.84    0.76      36     289    1.78   14.72
           c9t5d2   23.05    1.06      46     372    3.62   17.83
           c9t6d0   23.65    0.74      40     322    2.08   17.16
           c9t6d6   19.04    0.50      28     223    0.01   15.05
          c19t0d4   58.72    9.55     200    1597   31.99   14.60
          c19t0d5   51.30    8.87     174    1390   30.64   15.28
          c19t0d6   56.91    7.09     180    1441   24.49   14.90
          c19t0d7   55.71    7.12     179    1430   24.78   15.41
          c19t1d0   54.91    7.96     175    1396   28.06   15.43
          c19t1d1   55.91    8.70     188    1504   30.61   15.12
          c19t1d2   55.31    8.07     179    1435   27.21   15.25
          c19t1d3   54.91    8.53     186    1485   28.86   14.98
          c20t1d4   55.31    9.05     182    1454   30.60   15.06
          c20t1d5   56.91   12.45     186    1486   41.73   15.51
          c20t1d6   55.51   10.49     183    1461   34.74   14.73
          c20t1d7   54.71    8.07     173    1387   27.26   15.59
          c20t2d0   56.71    6.91     177    1414   23.97   15.36
          c20t2d1   56.31    6.54     174    1395   20.73   14.67
          c20t2d2   57.11    9.53     186    1491   31.22   15.03
          c20t2d3   54.71   10.66     186    1491   35.68   15.22
          c18t2d1   35.07    2.26     120     957    3.73    7.30
          c18t2d2   32.67    1.88     120     964    2.89    7.12
          c18t2d3   32.46    1.92     117     939    2.98    6.97
          c18t2d4   35.07    1.64     118     946    2.47    7.57
          c21t2d5   36.27    2.25     130    1042    4.62    8.14
          c21t2d6   37.27    2.50     126    1012    5.23    8.82
          c21t2d7   35.87    2.27     119     956    4.56    8.42
          c21t3d0   35.07    1.78     109     872    3.64    8.76
          c21t3d1   39.08    1.53     126    1012    2.88    8.16
          c21t3d2   18.04    0.50     184    4186    0.00    1.00
          c18t0d7   14.63   15.77     140    1121   22.46    6.88
          c21t1d0   15.43   13.28     103     832   26.19   10.19

    what are those ora_lgwr_codb, ora_dbw1_codb, ora_dbw2_codb, ora_dbw3_codb , ora_dbw0_codb process for ? where is the possible bottleneck and how to improve the situation ?

     Any word will be high appreciated.

Joe Received on Thu Aug 02 2007 - 10:59:57 CDT