I also notice a very high CPU load in the hosts after running /etc/rc.local:


top - 11:00:15 up 6 min,  1 user,  load average: 9.88, 4.09, 1.62
Tasks: 369 total,   9 running, 354 sleeping,   0 stopped,   6 zombie
%Cpu(s):  0.1 us,  5.7 sy,  0.0 ni, 94.2 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 13188960+total, 13057571+free,   746472 used,   567416 buff/cache
KiB Swap:        0 total,        0 free,        0 used. 13023952+avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                                
  884 root      20   0   52032  21652  17148 R 100.0  0.0   2:06.06 systemd-journal                                                                                                        
 2235 root      20   0       0      0      0 S  25.9  0.0   0:29.72 kworker/1:2                                                                                                            
  270 root      20   0       0      0      0 S  24.3  0.0   0:28.07 kworker/17:1                                                                                                           
  272 root      20   0       0      0      0 R  23.9  0.0   0:27.08 kworker/4:1                                                                                                            
  273 root      20   0       0      0      0 S  23.9  0.0   0:28.75 kworker/5:1                                                                                                            
  267 root      20   0       0      0      0 S  23.3  0.0   0:27.92 kworker/3:1                                                                                                            
   45 root      20   0       0      0      0 S  22.9  0.0   0:27.52 kworker/7:0                                                                                                            
  235 root      20   0       0      0      0 S  22.3  0.0   0:25.20 kworker/0:2                                                                                                            
  266 root      20   0       0      0      0 S  22.3  0.0   0:26.04 kworker/2:1                                                                                                            
  274 root      20   0       0      0      0 S  22.3  0.0   0:26.84 kworker/21:1                                                                                                           
  260 root      20   0       0      0      0 S  21.6  0.0   0:26.14 kworker/6:1                                                                                                            
  276 root      20   0       0      0      0 S  21.3  0.0   0:23.96 kworker/20:1                                                                                                           
  314 root      20   0       0      0      0 S  21.3  0.0   0:25.15 kworker/19:1                                                                                                           
  316 root      20   0       0      0      0 S  20.6  0.0   0:24.92 kworker/23:1                                                                                                           
  315 root      20   0       0      0      0 S  19.9  0.0   0:22.49 kworker/16:1                                                                                                           
  275 root      20   0       0      0      0 S  19.6  0.0   0:22.25 kworker/18:1                                                                                                           
  326 root      20   0       0      0      0 S  19.3  0.0   0:22.42 kworker/22:1                                                                                                           
  233 root      20   0       0      0      0 S  16.9  0.0   0:17.46 kworker/12:1                                                                                                           
  183 root      20   0       0      0      0 S  14.6  0.0   0:16.10 kworker/13:1                                                                                                           
 1499 root      20   0       0      0      0 S  14.3  0.0   0:16.48 kworker/14:2                                                                                                           
  208 root      20   0       0      0      0 S  14.0  0.0   0:16.64 kworker/11:1                                                                                                           
  271 root      20   0       0      0      0 S  14.0  0.0   0:16.30 kworker/15:1                                                                                                           
  320 root      20   0       0      0      0 S  13.6  0.0   0:14.60 kworker/28:1                                                                                                           
  269 root      20   0       0      0      0 S  13.3  0.0   0:15.68 kworker/10:1                                                                                                           
  268 root      20   0       0      0      0 S  12.3  0.0   0:14.36 kworker/9:1                                                                                                            
  280 root      20   0       0      0      0 S  11.0  0.0   0:13.05 kworker/25:1                                                                                                           
  281 root      20   0       0      0      0 S  11.0  0.0   0:12.36 kworker/31:1                                                                                                           
  184 root      20   0       0      0      0 S  10.3  0.0   0:30.89 kworker/29:1                                                                                                           
  278 root      20   0       0      0      0 S  10.3  0.0   0:12.57 kworker/30:1                                                                                                           
  279 root      20   0       0      0      0 S   9.3  0.0   0:12.26 kworker/27:1                                                                                                           
  277 root      20   0       0      0      0 S   8.0  0.0   0:09.98 kworker/26:1                                                                                                           
  282 root      20   0       0      0      0 S   7.6  0.0   0:09.02 kworker/24:1                                                                                                           
    8 root      20   0       0      0      0 S   1.3  0.0   0:01.80 rcu_sched             
....