[Mimedefang] High CPU Load Average

[An.H.Nguyen]

One if my two Solaris servers has very high CPU load Average and the 
Milter-graylist process takes high CPU usage.
We use BigBrother to monitor and report CPU Avage Load. (Each server takes 
50% work load from the DNS distribution balancer)
It shows LOAD AVG on hestia is above 250 a couple of times a day (high for 5 
minutes then back to around 60 to 90) while LOAD AVG on demeter is 0.66 in 
the last 4 days
Each server proccesses 30 thousand emails daily and it runs spamassassin, 
mine-defang software. Both servers has two 900MHZ CPUs with 4GB of RAM.
We run mimedefang version 2.51 and SpamAssassin version 3.0.3  running on 
Perl version 5.8.0

I think that there is an application problem on Hestia but do not know 
what's wrong. It looks like milter-greylist proccess put the a high load on 
the cpu. Is there a problem here?
Any help will be very appreciated.
Thanks,
An H. Nguyen

Instant snapshots from 'top' command:

Problem host: 'hestia'

load averages:  1.20,  1.33,  1.42 
hestia                                                       15:19:09
69 processes:  66 sleeping, 1 stopped, 2 on cpu
CPU states: 41.2% idle, 55.9% user,  2.9% kernel,  0.0% iowait,  0.0% swap
Memory: 4.0G real, 3.3G free, 214M swap in use, 7.9G swap free

   PID USERNAME THR PR NCE  SIZE   RES STATE   TIME FLTS    CPU COMMAND
  1958 smmsp     49 48   0 46.9M 45.8M cpu00  36:48    0 22.59% 
milter-greylist
   776 defang     4 23   0 35.3M 34.5M sleep   0:09    0  5.99% 
mimedefang.pl
   965 defang     4 20   0 32.1M 31.2M sleep   0:02    0  4.09% 
mimedefang.pl
   701 root       1 58   0 2560K 1536K cpu01   0:01    0  0.63% top
  1912 root      58 58   0 39.2M 37.6M sleep   2:10    0  0.62% ismilter
  1956 defang    74 58   0 4128K 3152K sleep   1:07    0  0.49% mimedefang
 22038 root      14 58   0 3128K 1832K sleep   1:43    0  0.23% syslogd
  1961 root       1 43   0 2888K 1680K sleep   0:19    0  0.11% sendmail
   978 root       1 48   0 3312K 2648K sleep   0:00    0  0.11% sendmail
  1942 defang     3 58   0 3576K 1592K sleep   0:13    0  0.10% 
mimedefang-mult
   987 root       1 58   0 3328K 2648K sleep   0:00    0  0.09% sendmail
   986 root       1 58   0 3336K 2656K sleep   0:00    0  0.09% sendmail
   988 root       1 58   0 3336K 2664K sleep   0:00    0  0.07% sendmail
   993 root       1 53   0 3304K 2512K sleep   0:00    0  0.02% sendmail
   979 root       1 55   0 3312K 2528K sleep   0:00    0  0.02% sendmail




Normal  host 'demeter'
load averages:  0.86,  1.18,  1.34 
demeter                                                      15:18:13
55 processes:  52 sleeping, 1 running, 1 stopped, 1 on cpu
CPU states: 27.8% idle, 69.4% user,  2.8% kernel,  0.0% iowait,  0.0% swap
Memory: 5.0G real, 4.3G free, 190M swap in use, 4.3G swap free

   PID USERNAME THR PR NCE  SIZE   RES STATE   TIME FLTS    CPU COMMAND
 17104 smmsp     36 58   0 44.8M 43.7M sleep  36:01    0 12.21% 
milter-greylist
 16025 defang     1 50   0 31.7M 31.0M run     0:10    0  6.91% 
mimedefang.pl
 16210 root       1 58   0 2560K 1544K cpu00   0:00    0  1.31% top
 17058 root      40 59   0 37.0M 35.3M sleep   2:12    0  0.39% ismilter
 17101 defang    55 58   0 3648K 2680K sleep   1:05    0  0.34% mimedefang
 17107 root       1 38   0 2888K 1672K sleep   0:20    0  0.11% sendmail
 16260 root       1 58   0 3336K 2656K sleep   0:00    0  0.11% sendmail
 16239 root       1 58   0 3328K 2656K sleep   0:00    0  0.10% sendmail
  4456 root       1 58   0 6568K 2720K sleep   0:03    0  0.10% sshd
 10562 root      14 58   0 3144K 1856K sleep   1:40    0  0.09% syslogd
 16052 defang     1 40   0 28.8M 28.1M sleep   0:03    0  0.07% 
mimedefang.pl
 16245 root       1 48   0 3336K 2664K sleep   0:00    0  0.06% sendmail
 16258 root       1 48   0 3320K 2648K sleep   0:00    0  0.06% sendmail
 16251 root       1 56   0 3336K 2640K sleep   0:00    0  0.05% sendmail
 16265 root       1 58   0 3320K 2528K sleep   0:00    0  0.05% sendmail