We recognize that our foreman installation slows down more and more. We actually manage around 200 hosts (vsphere) with Foreman. We each new host the ui become more unresponsive.
An example. We are on the dashboard and click "All hosts" than these page often not loaded because the reload intervall is shorter then the time for loading the overview.

We already checkt the database but here we have 300 - 400 MB of data, not a problem.
We also checkt load and memory usage of the foreman server.

# top -n1 -u foreman

Tasks: 162 total,   1 running, 161 sleeping,   0 stopped,   0 zombie
%Cpu(s): 14,4 us,  0,8 sy,  0,0 ni, 84,4 id,  0,3 wa,  0,0 hi,  0,1 si,  0,0 st
KiB Mem :  4046456 total,   438380 free,  3275508 used,   332568 buff/cache
KiB Swap:  1949692 total,  1658756 free,   290936 used.   497804 avail Mem 

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                                                                                                                                                                  
 1072 foreman   20   0   45276   3880   3508 S   0,0  0,1   0:00.05 systemd                                                                                                                                                                  
 1078 foreman   20   0   61560    104      0 S   0,0  0,0   0:00.00 (sd-pam)                                                                                                                                                                 
 1826 foreman   20   0 1401496 498964   9304 S   0,0 12,3  22:56.48 foreman-tasks                                                                                                                                                            
 1828 foreman   20   0  216956  12476   2456 S   0,0  0,3   0:14.68 foreman-tasks                                                                                                                                                            
 7209 foreman   20   0 1232116 357128  10580 S   0,0  8,8   0:04.84 ruby                                                                                                                                                                     
 9407 foreman   20   0 1348980 433472  10052 S   0,0 10,7   3:28.60 ruby                                                                                                                                                                     
17596 foreman   20   0 1285828 388844  10852 S   0,0  9,6   0:09.22 ruby                                                                                                                                                                     
17837 foreman   20   0 1285924 406168  11000 S   0,0 10,0   0:09.05 ruby                                                                                                                                                                     
27818 foreman   20   0 1347852 478160  10220 S   0,0 11,8 158:38.60 ruby                                                                                                                                                                     
27833 foreman   20   0 1479020 526148  10316 S   0,0 13,0  53:49.93 ruby 

# free -m
              total        used        free      shared  buff/cache   available
Mem:           3951        3197         428           3         325         486
Swap:          1903         284        1619

So it's inconspicuous.

What suggestions you can give us to improve the performance of the WebUI?