How to adjust datax jvm paramter , eg: -Xmn

[heichong]

in datax：
I want to adjust the jvm parameter : -Xmn. Is there any way to adjust the size of the Eden in the JVM heap?

I would like to explain why it is necessary to adjust the size of the Eden :

My datax task JVM STAT as follows:

[root@dw-test3 ~]# jstat -gcutil 8383 2000
  S0     S1     E      O      M     CCS    YGC     YGCT    FGC    FGCT     GCT
  0.00   0.00  22.01   0.00  17.41  19.80      0    0.000     0    0.000    0.000
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.01   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.67   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.67   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.67   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.67   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  12.67   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00   0.00  86.55   1.67  97.60  92.79      1    0.023     1    0.038    0.061
  0.00  54.65  68.69   1.68  96.27  91.93      3    0.111     1    0.038    0.149
 43.43   0.00   9.49   1.68  96.67  91.94      6    0.165     1    0.038    0.203
 51.14   0.00  77.04   2.14  96.98  92.00      8    0.204     1    0.038    0.242
  0.00  73.63  30.38   2.16  97.20  92.00     11    0.257     1    0.038    0.295
  0.00  56.51  74.43   2.17  97.30  92.00     13    0.282     1    0.038    0.320
 54.75   0.00  49.33   2.18  96.49  92.00     16    0.371     1    0.038    0.409
  0.00  99.69  25.02   2.18  96.59  92.00     19    0.401     1    0.038    0.439
  0.00  99.53  98.56   2.19  96.68  92.00     21    0.428     1    0.038    0.466
 62.42   0.00  73.97   2.21  96.77  92.00     24    0.487     1    0.038    0.525
  0.00  67.14  58.38   2.22  96.95  92.02     27    0.546     1    0.038    0.584
 71.37   0.00  47.31   2.22  97.00  92.02     30    0.618     1    0.038    0.656
 69.37   0.00  63.19   2.39  97.09  92.02     32    0.703     1    0.038    0.741
 65.34   0.00  93.22   2.39  97.18  92.02     34    0.750     1    0.038    0.788
  0.00  66.85  38.95   2.40  97.39  92.02     37    0.783     1    0.038    0.821
 71.59   0.00  32.04   2.40  96.48  92.02     40    0.805     1    0.038    0.843
  0.00  76.98  15.38   2.41  96.57  92.02     43    0.835     1    0.038    0.873
 77.79   0.00  79.99   2.41  96.64  92.02     44    0.852     1    0.038    0.890
  0.00  86.15  44.69   2.41  96.86  92.02     47    0.878     1    0.038    0.916
 69.63   0.00  76.03   2.50  96.90  92.02     50    0.953     1    0.038    0.991
  0.00  99.88  18.46   3.05  96.98  92.02     53    0.991     1    0.038    1.030
  0.00  63.40  16.15   4.00  96.99  92.02     55    1.034     1    0.038    1.072
  0.00  65.21  85.22   4.01  97.04  92.03     57    1.049     1    0.038    1.087
 65.76   0.00  28.17   4.01  97.26  92.03     60    1.071     1    0.038    1.109
 62.16   0.00  90.94   4.02  97.29  92.03     62    1.101     1    0.038    1.139
  0.00  56.07  81.18   4.02  97.31  92.03     65    1.158     1    0.038    1.196
  0.00  99.65  87.63   4.02  97.35  92.03     67    1.194     1    0.038    1.232
 37.59   0.00  33.82   4.03  96.42  92.03     70    1.229     1    0.038    1.267
  0.00  99.07  14.78   4.04  96.45  92.03     73    1.268     1    0.038    1.306
  0.00  50.41  51.34   4.04  96.50  92.03     75    1.302     1    0.038    1.340
 50.27   0.00  51.13   4.05  96.53  92.03     78    1.327     1    0.038    1.365
  0.00  58.73   3.42   4.06  96.60  92.03     81    1.363     1    0.038    1.401
 93.10   0.00  99.47   4.07  96.61  92.03     82    1.370     1    0.038    1.408
  0.00  56.89  47.73   4.07  96.69  92.03     85    1.426     1    0.038    1.464
 95.34   0.00  38.52   4.07  96.78  92.03     88    1.472     1    0.038    1.510
  0.00  99.64  95.99   4.08  97.53  92.03     91    1.510     1    0.038    1.548
 49.77   0.00  66.33   4.08  97.54  92.03     94    1.559     1    0.038    1.597
  0.00  66.19   7.67   4.11  97.55  92.03     97    1.614     1    0.038    1.653
  0.00  68.09  77.38   4.12  97.55  92.03     99    1.630     1    0.038    1.668
  0.00  58.88  62.86   4.19  97.55  92.03    103    1.661     1    0.038    1.699
 59.34   0.00  31.27   4.19  97.56  92.03    104    1.669     1    0.038    1.707
 59.34   0.00  31.27   4.19  97.56  92.03    104    1.669     1    0.038    1.707
 59.34   0.00  31.27   4.19  97.56  92.03    104    1.669     1    0.038    1.707
 59.34   0.00  31.27   4.19  97.56  92.03    104    1.669     1    0.038    1.707
 59.34   0.00  34.20   4.19  97.56  92.03    104    1.669     1    0.038    1.707

We can find that YGC occurred 104 times, while FGC only occurred once;
As of the end of the task, the old only used 4% of memory, while the other 96% of memory was wasted.

so,I want to increase the size of the Eden memory

 public String loadJvmEnv(DataxParameters dataXParameters) {
        int xms = Math.max(dataXParameters.getXms(), 1);
        int xmx = Math.max(dataXParameters.getXmx(), 1);
        return String.format(JVM_PARAM, xms, xmx);
    }

But, It was found in the source code that only Xms and Xmx can be adjusted，How to adjust -Xmn ？

[heichong]

I think it's possible to add a parameter to the page: jvmArgs, so that users can fine-tune the jvm parameters