如何定义内存使用量
| time | before GC(MB) | after GC(MB) | |
| 19:23:23 | 2807442 | 2663288 | |
| 19:24:04 | 2696290 | 2575996 | old GC |
| 19:31:06 | 3233018 | 2553234 | |
| 19:35:02 | 3189076 | 2605652 | |
| 19:37:34 | 3012064 | 2605270 | |
| 19:40:33 | 3073020 | 2617134 | |
| 19:43:21 | 3133246 | 2629384 | |
| 19:46:46 | 3176390 | 2639902 | |
| 19:49:30 | 3151098 | 2629860 | |
| 19:50:12 | 2762622 | 2447828 | old GC |
| 19:56:09 | 3192812 | 2293238 | |
| 20:42:40 | 3173658 | 2315198 |
memory cost about 60GB
before job started, gc reached to about 2.56TB
during job, gc reached to about 2.62TB, which means 10 threads hold about 60G memory
