Upgrade to clamav 0.90.2 makes scanning extremely slow

DAve dave.list at pixelhammer.com
Thu Apr 26 22:06:19 IST 2007

Richard Lynch wrote:
> Julian Field wrote:
>> Hash: SHA1
>> What's wrong with just using clamavmodule? You need to use 
>> Mail::ClamAV 0.20 with ClamAV 0.90 and later, which is all included in 
>> my ClamAV+SA package.
>> I don't understand the sudden rush to clamd at all. Can someone 
>> explain to me please?
>> Jules.
> The only advantage I see is that it's all maintained by a single 
> source.  That is, the ClamAV team maintains clamd and clamdscan 
> together.  There's no third party perl package that may not be up to 
> date.  I don't know if there's a performance improvement one way or the 
> other.  It's conceivable that clamdscan/clamd performs better in a 
> multiprocessor environment by spreading the load across other 
> processors.  It's just as possible that the overhead of the 
> communications between the two costs too much to justify doing it that way.
> I would probably suggest that clamdscan/clamd always be used instead of 
> just clamscan.  From what I've seen using clamscan alone is the worst 
> possible case performance wise.
> Rich

I can't disagree with that but I can say performance is not unreasonable 
using clamscan. Messages for us take from 2 to 6 seconds to process in 
batches from 1 to 4 messages. We stop most of our messages long before 
they ever hit AV scanning. Not using clamdscan or clamavmodule leaves us 
with one less process to monitor on our MS servers, and changes/updates 
made by the ClamAV team have never adversely affected us (so far...).

We may move up to clamdscan or clamavmodule in the near future when we 
upgrade the MS servers, but right now I can see no compelling reason to 
do so. I tend to always favor stability over performance, and I abhor 
surprises on Monday mornings. Call me a Luddite, but new ain't always 

Also, it's not like we don't process a few connections either, here are 
a single days stats for one of our servers.

Rejected by Greylisting       196,047
Blocked for Pipelining         11,072
Blocked for RFC                18,528
Blocked for RBL                94,857
Blocked for Bad Sender          2,746
Blocked for No Account         12,000
Found Spam Message             18,778
Messages Delivered             33,840


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logo change for Memorial Day. Why do they choose to do logos
for other non-international holidays, but nothing for

Maybe they forgot who made that choice possible.

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