How do I limit the maximum children for spamd? For if there is a large spam attack – too many processes are started and the system can run out of resources.

How do I limit the maximum children for spamd? For if there is a large spam attack – too many processes are started and the system can run out of resources.
RESOLUTION
In Plesk 7.5 and 8.0 you can limit the number of simultaneously running SpamAssassin processes with ‘SPAMASSASSIN_MAX_CHILDREN’ option in /etc/psa/psa.conf:

SPAMASSASSIN_MAX_CHILDREN 5

You can specify a desired value then restart psa-spamassassin.
If the line is omitted then the default value is 20 for SpamAssassin 2.6 and 5 for SpamAssassin 3.x.

Since Plesk 8.1 SPAMASSASSIN_MAX_CHILDREN option is obsoleted but this value can be managed through Plesk CP. Use “The maximum number of worker spamd processes to run (1-5)” on the Settings tab of Server>SpamFilter page. The value is stored in psa.misc table (param=’spamfilter_max_children’).

SpamAssassin cannot be started: “Unable to make action: Unable to manage service by spamd: Empty error message from utility”

SpamAssassin cannot be started: “Unable to make action: Unable to manage service by spamd: Empty error message from utility.”
RESOLUTION

Full error message:

Unable to make action: Unable to manage service by spamd: Empty error message from utility. 0: /usr/local/psa/admin/htdocs/server/restart_services.php:19 psaerror(string “Unable to make action: Unable to manage service by spamd: Empty error message from utility.”)

Try to start psa-spamassassin from the command line:

/etc/init.d/psa-spamassassin start
Can’t locate Text/Iconv.pm in @INC (@INC contains:
/usr/local/lib/perl5/5.8.7/i686-
linux /usr/local/lib/perl5/5.8.7
/usr/local/lib/perl5/site_perl/5.8.7/i686-linux
/usr/local/lib/perl5/site_perl/5.8.7 /usr/local/psa/lib/perl5/5.8.7
/usr/local/psa/lib/perl5/5.8.7/i686-linux
/usr/local/psa/lib/perl5/site_perl/5.8.7/i686-linux
/usr/local/psa/lib/perl5/site_perl/5.8.7 /usr/lib/perl5/site_perl/5.8.0
/usr/local/lib/perl5/site_perl) at
/usr/lib/perl5/site_perl/5.8.0/Mail/SpamAssassin/CmdManage.pm line 8.
BEGIN failed–compilation aborted at
/usr/lib/perl5/site_perl/5.8.0/Mail/SpamAssassin/CmdManage.pm line 8.
Compilation failed in require at /usr/local/psa/admin/sbin/spammng line 71.

This error means that there is something wrong with Perl itself because it cannot find all needed modules. Make sure that all RPMs required for ‘Spamassassin’ are installed.

Check Perl version:

perl -v
rpm -q perl

And package integrity with the command:

rpm -V perl

Reinstall Perl RPM if versions which are shown by these commands don’t match or integrity test shows any errors.