Questions regarding imaptest

[rub zorghy]

Sorry, I forgot to specify my workload :

./imaptest-1.0.0/src/imaptest secs=300 clients=800 seed=123
userfile=/tmp/userlist_imaptest no_tracking mbox=/tmp/dovecot-crlf

with dovecot-crlf : http://www.dovecot.org/tmp/dovecot-crlf

Kind regards, rub

2015-01-14 15:50 GMT+01:00 rub zorghy <gdrub13 at gmail.com>:

> Hi,
>
> The measurements were created under the following conditions :
>
> • operating system : Red Hat Enterprise Linux Server release 6.6
> (Santiago) kernel in version 2.6.32-504.el6.x86_64
> • virtual server (VMware) with an Intel(R) Xeon(R) 4vCPU E5649 x 2,526 GHz
> (2 cores per virtual socket) and 4 GB RAM
> • 7,200 RPM SATA 1TB (FC SAN IBM System Storage N3400)
> • all file systems had been formated in ext4
> • Dovecot v.2.0.9
> • imaptest v.1.0.0
> • LDAP 389 Directory Server v.1.2.2
> • free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches
> and services restarted before the test
>
> "Tuning" based upon the book « *Dovecot: POP3/IMAP servers for
> enterprises and ISPs* » Peer Heinlein :
>
>  ---%<------------------------------------------
>
> imap {} (10-master.conf).
> service imap {
> [...]
> process_limit = 8192
> [...]
> }
>
> auth {}
> service auth {
> [...]
> client_limit = 9516
> [...]
> }
>
> process_min_avail = 16
>
>  ---%<------------------------------------------
>
> mail_max_userip_connections = 100
>
> The test results shows :
>
> Logi List Stat Sele Fetc Fet2 Stor Dele Expu Appe Logo
> 100%  50%  50% 100% 100% 100%  50% 100% 100% 100% 100%
>                           30%                  5%
>  324  142  128  263  299  405   92  153  320  336  335 800/800
>  212   92   92  182  166  233   59   87  178  201  202 800/800
>  - 4051 stalled for 16 secs in command: 8 APPEND "INBOX" () {3251+}
>  315  160  134  300  275  400   85  136  300  317  317 800/800
>  - 4051 stalled for 17 secs in command: 8 APPEND "INBOX" () {3251+}
>  247  130  163  292  251  366   99  115  239  240  240 800/800
>  222  122  117  234  279  383  112  147  263  222  222 800/800
>  188   93   94  177  168  232   65   87  162  196  195 800/800
>  290  126  119  260  262  383  102  126  283  282  283 800/800
>  240  125  107  243  259  353  102  130  253  256  256 800/800
>  276  158  144  291  280  400  101  149  266  261  261 800/800
>  254   95   89  189  235  313   78  118  243  253  253 800/800
>   82  829  926  861  722  593  455  628 1695 2252    4 ms/cmd avg
>
> Logi List Stat Sele Fetc Fet2 Stor Dele Expu Appe Logo
> 100%  50%  50% 100% 100% 100%  50% 100% 100% 100% 100%
>                           30%                  5%
>  148   59   55  126  119  174   43   64  130  147  147 800/800
>  - 8770 stalled for 16 secs in command: 4 FETCH 1:2 (INTERNALDATE UID
> INTERNALDATE)
>  261  128  139  247  252  369  101  125  258  269  269 800/800
>  302  159  158  307  282  398  109  126  296  298  297 800/800
>  234   96  118  239  270  369   98  138  357  428  427 800/800
>  361  213  220  450  383  596  151  197  240  165  166 800/800
>  192   93   92  206  256  352  104  118  297  289  290 800/800
>  - 9806 stalled for 16 secs in command: 4 FETCH 1 (RFC822.SIZE)
>  245   85   72  162  128  190   52   73  157  174  173 800/800
>  - 9806 stalled for 17 secs in command: 4 FETCH 1 (RFC822.SIZE)
>  294  152  165  348  360  526  136  179  313  308  309 800/800
>  272   87   79  174  164  229   54   85  218  230  230 800/800
>  218  152  152  310  325  467  117  152  265  236  221 798/800
>  119  830  852  859  707  566  511  702 1672 2161    6 ms/cmd avg
>
> I have three questions :
>
> 1) how to interpret each row except the last one ?
>
> 2) how to explain the stalled commands ?
>
> 3) why benchmark shows too few read disk I/O ?
>
> Thanks so much,
>
> rub
>
>