using dbt2 postgresql 8.4 - rampup time issue

Hi,

We are using dbt2 to check performance of postgresql 8.4 on Linux64 machine. When we increase "TERMINALS PER WAREHOUSE" TPM value increase rapidly but rampup time increase too , dbt2 estimated rampup time calculation do not work properly that’s why it run the test for wrong duration i.e.

1.
Settings :
    DATABASE CONNECTIONS: 50
    TERMINALS PER WAREHOUSE: 10
    SCALE FACTOR (WAREHOUSES): 200
    DURATION OF TEST (in sec): 7200
Result :
                             Response Time (s)
     Transaction      %    Average :    90th %        Total        Rollbacks      %
    ------------  -----  ---------------------  -----------  ---------------  -----
        Delivery   3.96      0.285 :     0.023        26883                0   0.00
       New Order  45.26      0.360 :     0.010       307335             3082   1.01
    Order Status   3.98      0.238 :     0.003        27059                0   0.00
         Payment  42.82      0.233 :     0.003       290802                0   0.00
     Stock Level   3.97      0.245 :     0.002        26970                0   0.00
    ------------  -----  ---------------------  -----------  ---------------  -----
    
    2508.36 new-order transactions per minute (NOTPM)
    120.1 minute duration
    0 total unknown errors
    2000 second(s) ramping up

2.
Settings :
    DATABASE CONNECTIONS: 50
    TERMINALS PER WAREHOUSE: 40
    SCALE FACTOR (WAREHOUSES): 200
    DURATION OF TEST (in sec): 7200
Result :
                             Response Time (s)
     Transaction      %    Average :    90th %        Total        Rollbacks      %
    ------------  -----  ---------------------  -----------  ---------------  -----
        Delivery   3.95      8.123 :     4.605        43672                0   0.00
       New Order  45.19     12.205 :     2.563       499356             4933   1.00
    Order Status   4.00      7.385 :     3.314        44175                0   0.00
         Payment  42.89      7.221 :     1.920       473912                0   0.00
     Stock Level   3.97      7.093 :     1.887        43868                0   0.00
    ------------  -----  ---------------------  -----------  ---------------  -----
    
    7009.40 new-order transactions per minute (NOTPM)
    69.8 minute duration
    0 total unknown errors
    8016 second(s) ramping up
3.
Settings :
    DATABASE CONNECTIONS: 50
    TERMINALS PER WAREHOUSE: 40
    SCALE FACTOR (WAREHOUSES): 200
    DURATION OF TEST (in sec): 7200
Result :
                             Response Time (s)
     Transaction      %    Average :    90th %        Total        Rollbacks      %
    ------------  -----  ---------------------  -----------  ---------------  -----
        Delivery   3.98      9.095 :    16.103        15234                0   0.00
       New Order  45.33      7.896 :    14.794       173539             1661   0.97
    Order Status   3.96      8.165 :    13.989        15156                0   0.00
         Payment  42.76      7.295 :    12.470       163726                0   0.00
     Stock Level   3.97      7.198 :    12.520        15198                0   0.00
    ------------  -----  ---------------------  -----------  ---------------  -----
    
    10432.09 new-order transactions per minute (NOTPM)
    16.3 minute duration
    0 total unknown errors
    11227 second(s) ramping up
    
These results show that dbt2 test actually did not run for 2 hours but it start varying with the increase of  "TERMINALS PER WAREHOUSE" value i.e. 1st Run ( 120.1 minute duration ), 2nd Run (69.8 minute duration) and 3rd Run (16.3 minute duration).

To fix and sync with the rampup time, I have made a minor change in the dbt2-run-workload script i.e.

    --- dbt2-run-workload      2010-07-02 08:18:06.000000000 -0400
    +++ dbt2-run-workload   2010-07-02 08:20:11.000000000 -0400
    @@ -625,7 +625,11 @@
     done
    
     echo -n "estimated rampup time: "
    -do_sleep $SLEEP_RAMPUP
    +#do_sleep $SLEEP_RAMPUP
    +while ! grep START ${DRIVER_OUTPUT_DIR}/*/mix.log ; do
    +       sleep 1
    +done
    +date
     echo "estimated rampup time has elapsed"
    
     # Clear the readprofile data after the driver ramps up.
 
What is rempup time ? And what do you think about the patch?. Can you please guide me?. Thanks.

Best Regards,
Asif Naeem

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