Benchmarking auth

[micah anderson]

Hello,

I'm attempting to use imaptest to test auths/sec on my imap server, to
simulate the number I'm getting now on a new server. Based on my
readings of dovecot stats outputs, my current machine is doing somewhere
between 11.6 and 196 logins/sec at its busiest, and I want to make sure
the new server can handle that amount.

With imaptest I attempt to simulate this by just simulating login/logout
speed, but I'm not sure I understand the results and where things are
being blocked.

For testing purposes, I set:

  mail_max_userip_connections = 6000
  mail_max_userip_connections = 6000
  auth_worker_max_count = 240

If you have some additional suggestions for what I can also tweak here
to improve this, I would like to know.

I then ran imaptest with:

imaptest clients=196 user=test pass=testpw host=127.0.0.1 port=14300 - select=0 seed=123 secs=300

It doesn't seem like I can simulate *only* authentications/logins. I
have to pair them with logouts. It makes me wonder how I can simulate
the amount of load on my current live system on this system.

How do I read the output? I don't really understand what is being shown
here:

Logi Logo 
100% 100% 
   0    0 100/100 [51%]

does this mean that it tried 100 logins and 100 logouts and 51%
succeeded? What are the first two columns?
   
   7    7 104/121 [61%]
   6    6 131/139 [70%]
   3    3 137/148 (84 stalled >3s) [75%]
84 stalled for more than 3 seconds, how does this relate to the other
values presented?

   5    5 155/163 (79 stalled >3s) [83%]
   1    1 166/166 (107 stalled >3s) [84%]
   2    2 168/172 (128 stalled >3s) [87%]
   6    5 179/190 (140 stalled >3s) [96%]
  22   22 182/196 (136 stalled >3s)
   4    3 195/196 (133 stalled >3s)
5845  129 ms/cmd avg

I really wonder if these first two columns are ms/cmds?

It then continues:

Logi Logo 
100% 100% 
  10   11 195/196 (131 stalled >3s)
   7    8 194/196 (150 stalled >3s)
   3    3 194/196 (171 stalled >3s)
  10    9 192/196 (166 stalled >3s)
  22   22 182/196 (156 stalled >3s)
   8    9 193/196 (153 stalled >3s)
 - 2 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 7 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 8 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 9 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 11 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 12 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 14 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 22 stalled for 16 secs in command: 1 LOGIN "test" "testpw"
 - 25 stalled for 16 secs in command: 1 LOGIN "test" "testpw"

... it starts to build up like this, until I hit control-c twice:

 - 100 stalled for 17 secs in command: 1 LOGIN "test" "testpw"
^CInfo: Received second SIGINT - stopping immediately
11347  118 ms/cmd avg

Totals:
Logi Logo 
100% 100% 
 130  134 

What are these totals?

Thanks!
micah