# GC s1 always used 100%, never less than 100%

**URL:** <https://discuss.elastic.co/t/gc-s1-always-used-100-never-less-than-100/111076>\
**Category:** Elasticsearch\
**Created:** [December 11, 2017, 11:19am UTC](https://discuss.elastic.co/t/gc-s1-always-used-100-never-less-than-100/111076 "2017-12-11T11:19:45Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![Robin\_Guo](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/robin_guo/32/42297_2.png) [@Robin\_Guo](https://discuss.elastic.co/u/Robin_Guo)\
**Post date:** [December 12, 2017, 2:54am UTC](https://discuss.elastic.co/t/gc-s1-always-used-100-never-less-than-100/111076/3 "2017-12-12T02:54:41Z")

</div>

> [@colings86](#):
>
> this output. No GC has happened during this output (since YGC and FGC have not increased) so I would not expect S1 to change. The eden space (E) is increasing and close to being full so I would expect a young GC to happen soon after the end of this output at which point I would expect S1 to drop to 0 (as any surviving object will be moved to S0) and S0 to increase to some value between 0 and 100 depending on the survival rate of the objects in the Eden space.

hi @colings86,

I've been monitoring the GC for a while, even if the YGC changed , but S1 never changed , it always 100, I never ever see the s1 changed to some valule.

```
171212105051 root@esdata02 ~ # jstat -gcutil 28948 2000 100
  S0 S1 E O M CCS YGC YGCT FGC FGCT GCT
  0.00 100.00 75.41 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 76.08 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 76.17 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 76.27 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 76.56 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 76.65 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 77.03 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 77.22 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 77.32 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 77.89 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 78.09 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 78.18 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 78.47 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 78.56 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 78.85 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 79.04 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 79.23 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 79.52 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 79.71 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 79.90 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 80.00 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 80.00 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 80.29 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 80.67 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 82.58 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 84.02 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 84.50 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 84.78 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 85.17 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 87.94 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 88.42 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 89.00 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 89.28 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 93.30 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 94.93 82.10 91.54 82.89 2191 229.038 0 0.000 229.038
  0.00 100.00 8.53 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 12.40 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 13.95 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 15.50 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 21.71 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 28.68 55.35 91.54 82.89 2192 229.149 0 0.000 229.149
  0.00 100.00 29.46 55.35 91.54 82.89 2192 229.149 0 0.000 229.149

```

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