cockroachdb performance drop after pausing node

run1.log

$ block_writer
    1s: 1025.5/sec
    2s: 1097.1/sec
    3s:  915.0/sec
    4s:  940.8/sec
    5s:  903.9/sec
    6s:  810.9/sec
    7s:  987.9/sec
    8s:  940.5/sec
    9s:  811.3/sec
   10s:  815.3/sec
   11s:  921.7/sec
   12s:  667.5/sec
   13s:  785.7/sec
   14s:  813.9/sec
   15s:  958.7/sec
   16s:  939.1/sec
   17s:  898.9/sec
   18s:  953.1/sec
   19s:  892.1/sec
   20s:  798.5/sec
   21s:  909.0/sec
   22s:  957.2/sec
   23s:  939.6/sec
   24s:  953.2/sec
   25s:  955.0/sec
   26s:  952.8/sec
   27s:  745.1/sec
   28s: 1032.2/sec
   29s:  957.4/sec
   30s:  943.6/sec
   31s:  920.8/sec # paused node
   32s:  870.5/sec
   33s:  891.4/sec
   34s: 1101.1/sec
   35s: 1205.6/sec
   36s: 1160.8/sec
   37s: 1198.3/sec
   38s: 1174.2/sec
   39s:  939.8/sec
   40s: 1256.1/sec
   41s: 1231.1/sec
   42s: 1211.0/sec
   43s: 1014.2/sec
   44s:  985.6/sec
   45s: 1020.2/sec
   46s: 1205.5/sec
   47s: 1094.7/sec
   48s: 1135.4/sec
   49s: 1091.8/sec
   50s:  762.9/sec
   51s: 1041.6/sec
   52s: 1112.2/sec
   53s: 1041.3/sec
   54s: 1021.2/sec
   55s:  995.2/sec
   56s:  853.7/sec
   57s: 1063.1/sec
   58s: 1161.9/sec
   59s: 1154.4/sec
  1m0s: 1065.9/sec
  1m1s: 1009.0/sec
  1m2s:  868.6/sec
  1m3s: 1194.3/sec
  1m4s: 1098.4/sec
  1m5s: 1064.7/sec
  1m6s:  828.4/sec
  1m7s:  712.6/sec
  1m8s:  683.1/sec
  1m9s:  644.9/sec
 1m10s:  803.8/sec
 1m11s: 1058.6/sec
 1m12s: 1117.5/sec
 1m13s: 1039.0/sec
 1m14s:  972.9/sec
 1m15s:  832.4/sec
 1m16s:  998.1/sec
 1m17s: 1029.5/sec
 1m18s: 1127.6/sec
 1m19s: 1088.8/sec
 1m20s:  899.3/sec
 1m21s:  730.8/sec
 1m22s:  957.0/sec
 1m23s: 1087.1/sec
 1m24s: 1098.9/sec
 1m25s: 1108.8/sec
 1m26s: 1024.1/sec
 1m27s:  839.0/sec
 1m28s:  760.8/sec
 1m29s:    0.0/sec # performance drop
 1m30s:    0.0/sec
 1m31s:   13.0/sec
 1m32s: 1206.1/sec
 1m33s: 1170.0/sec
 1m34s: 1162.0/sec
 1m35s: 1026.3/sec
 1m36s:  882.1/sec
 1m37s: 1053.1/sec
 1m38s: 1177.5/sec
 1m39s: 1112.6/sec
 1m40s: 1086.9/sec
 1m41s:  947.0/sec
 1m42s:  897.7/sec
 1m43s: 1024.1/sec
 1m44s: 1057.3/sec
 1m45s: 1200.3/sec
 1m46s: 1128.7/sec
 1m47s:  903.6/sec
 1m48s:  903.8/sec
 1m49s:  897.1/sec
 1m50s:  937.4/sec

run2.log

$ block_writer
    1s: 1154.2/sec
    2s: 1066.4/sec
    3s:  970.9/sec
    4s:  976.7/sec
    5s:  883.3/sec
    6s:  821.5/sec
    7s:  972.5/sec
    8s:  906.9/sec
    9s:  835.0/sec
   10s:  782.7/sec
   11s:  909.9/sec
   12s:  838.3/sec
   13s:  782.8/sec
   14s:  977.4/sec
   15s:  945.2/sec
   16s:  926.5/sec
   17s:  954.0/sec
   18s:  831.0/sec
   19s:  845.9/sec
   20s:  737.0/sec
   21s:  925.0/sec
   22s:  940.9/sec
   23s:  865.0/sec
   24s:  846.0/sec
   25s:  805.8/sec
   26s:  768.1/sec
   27s:  717.0/sec
   28s:  818.0/sec
   29s:  919.8/sec
   30s:  861.2/sec # paused node
   31s:  818.9/sec
   32s:  971.0/sec
   33s: 1049.0/sec
   34s:  999.0/sec
   35s: 1242.0/sec
   36s: 1048.9/sec
   37s: 1058.1/sec
   38s: 1154.9/sec
   39s: 1070.1/sec
   40s:  931.0/sec
   41s: 1035.0/sec
   42s: 1082.0/sec
   43s: 1143.9/sec
   44s: 1088.1/sec
   45s:  972.0/sec
   46s:  707.9/sec
   47s:    0.0/sec # performance drop
   48s:    0.0/sec
   49s:  272.0/sec
   50s: 1157.9/sec
   51s: 1163.6/sec
   52s: 1099.8/sec
   53s:  936.5/sec
   54s:  894.7/sec
   55s:  957.0/sec
   56s: 1215.8/sec
   57s: 1147.5/sec
   58s: 1176.1/sec
   59s: 1173.9/sec
  1m0s:  898.4/sec
  1m1s: 1015.3/sec
  1m2s: 1164.7/sec
  1m3s: 1136.3/sec
  1m4s:  885.5/sec
  1m5s:  919.1/sec
  1m6s:  755.1/sec
  1m7s:  751.0/sec
  1m8s: 1144.1/sec