New MS install is slow to an extreme

Julian Field MailScanner at
Thu Apr 3 14:17:26 IST 2008

DAve wrote:
> Julian Field wrote:
>> DAve wrote:
>>> After much plugging away, double checking, triple checking and 
>>> herding of cats I *think* we may out of the woods. I won't know 
>>> until tomorrow AM when traffic picks up again. Here are my findings 
>>> so far.
>>> MailScanner 4.67.6
>>> ClamAV 0.92.1
>>> SpamAssassin 3.2.4
>>> Virus Scanners = [clamav | clamavmodule] - There appears to be no 
>>> real gain in running clamavmodule, some speed increase but not 
>>> enough to be noticed. I have clamavmodule configured just to save 
>>> some memory.
>>> ClamAV Full Message Scan = yes - That is a killer, it seems to 
>>> really increase processing time. I have it now set to no, and I have 
>>> removed my MSRBL sigs.
>>> Incoming Work Dir = tmpfs (mdmfs in FreeBSD) - Surprisingly little 
>>> difference. I left it on a memory file system for now.
>>> -> skip_rbl_checks 1 - Oddly does not do what it 
>>> claims. SA is still doing rbl checks. I commented out the DNSEval 
>>> plugin in v320.pre file and was rewarded with errors for my effort. 
>>> Not certain what the correct method of disabling rbl checks in SA is 
>>> now. Peter Farrow found a message where this has been seen already. 
>>> MailScanner batch size - With version 4.54.6 MS processed 10 
>>> messages per batch and kept up just fine. With version 4.67.6 it 
>>> will grab 30+ messages which takes longer to process. Increasing MS 
>>> children has no effect. More children working slower doesn't process 
>>> more mail for me. I don't see where I can configure this.
>> "Max Children =" in MailScanner.conf. If you were using 
>> upgrade_MailScanner_conf to upgrade your MailScanner.conf file then 
>> this setting would not have been changed between versions. Do you 
>> really copy over all your settings by hand into the new 
>> MailScanner.conf file? Wow! That must take *hours*.
> Nope, I can modify Max Children, my question is can I control how 
> large a batch size each child will process? Previously if I had 500 
> messages waiting each child would pick up 10 messages, now they will 
> each pick up 30 messages. This is clearly evident in my MRTG graphs 
> where I show over  the last four months I never had a batch over 10, 
> yesterday I had batch sizes of 30 for several hours.
Max Unscanned Bytes Per Scan = 100m
Max Unsafe Bytes Per Scan = 50m
Max Unscanned Messages Per Scan = 30
Max Unsafe Messages Per Scan = 30

> I do use upgrade_MailScanner_conf, and works a treat ;^)
Phew! You had me worried for a moment there :-)

> DAve
>>> I am currently seeing processing times of .8 to 20 seconds per 
>>> message, generally around the 2 to 4 seconds mark. This is for 
>>> batches of 1 to 10 messages. I was seeing as much as 800 seconds for 
>>> a batch size of 30 messages this morning. So there has been 
>>> improvement.
>>> I am compiling my SA rules and I run my RBLs in the MTA (hence why I 
>>> do not want rbl checking in SA).
>>> Overall, my previous install of MS 4.54.6, Clam .92, and SA 3.1.9 
>>> would run rings around this install. I am seriously contemplating 
>>> rolling back but I am uncertain if I have the original tarball for 
>>> Julian's Clam+SA package.
>>> I believe my issue is configuration of MS or SA at this point. I am 
>>> open to suggestions.
>>> Thanks for the help.
>>> DAve
>> Jules


Julian Field MEng CITP CEng
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