That's a very valid point.  I hesitated to mention it only because my 
experience with distributed mirrors has been that the files on each mirror are 
timestamped when the mirror you happen to be talking to at that moment 
downloaded the file which is inconsistent over the pool.  I wondered if, 
perhaps, the clamav mirroring structure had found a way around that issue, but 
when I see freshclam does either a DNS TXT check or a "first 512 byte header 
comparison" check it made me think this was still an issue and 
if-modified-since couldn't be relied upon to work until you got to the absolute 
last mirror to pull down the absolute newest version which could still be 
pretty inefficient overall (depending on the size of the pool compared to how 
often files change).  AND this issue would percolate down to the clients of the 
PrivateMirror unless, of course, the issue with differing timestamps from 
mirror to mirror has been resolved in some way.

So, I'm curious if your wget --timestamping approach has been tested in this 
context as truly downloading each file only once or if your point was to note 
the capability of the wget command?

Thanks,

Scott

________________________________
From: clamav-users <[email protected]> on behalf of Arjen 
de Korte via clamav-users <[email protected]>
Sent: March 23, 2020 4:35 PM
To: ClamAV users ML <[email protected]>
Cc: Arjen de Korte <[email protected]>
Subject: Re: [clamav-users] PrivateMirror set on client machine. Disable cld 
downloads

Citeren "Scott A. Wozny via clamav-users" <[email protected]>:

> One caveat with that suggestion is that if you move off of freshclam
> to do your signature retrieval with wget, you give up the
> efficiencies of just downloading the first 512 bytes of each DB file
> to see if it's been updated and, if not, going back to sleep until
> the next check.  Using wget you go from a few KB of bandwidth per
> server per check to hundreds of MB for each update on each server.
> If you don't care about bandwidth and disk I/O, then this difference
> won't matter to you, but if it does, just be aware of the difference.

The --timestamping option of wget will fix that for you and will only
download the file if the timestamp of the remote file changes:

     wget --timestamping http://database.clamav.net/daily.cvd

> Alternatively, you could emulate what freshclam does and curl the
> first 512 bytes, do the comparative version checking and then
> sleeping or doing the full download.  But once you get to that
> point, you're practically rewriting freshclam and then the option of
> reaching out to the devel list to modify freshclam to fit your needs
> for a custom build starts to become a comparable amount of work.
>
> Scott
>
> ________________________________
> From: clamav-users <[email protected]> on behalf
> of G.W. Haywood via clamav-users <[email protected]>
> Sent: March 23, 2020 12:32 PM
> To: ClamAV users ML <[email protected]>
> Cc: G.W. Haywood <[email protected]>
> Subject: Re: [clamav-users] PrivateMirror set on client machine.
> Disable cld downloads
>
> Hi there,
>
> On Mon, 23 Mar 2020, vin9999 via clamav-users wrote:
>
>> ... how can we disable .cld downloads? ...
>
> Use something else to download the files?
>
> Presumably you use freshclam to keep the private mirror up to date,
> but there is nothing which forces you to use freshclam to copy files
> from the private mirror to its clients.  A utility like 'wget' could
> do what you need.
>
> --
>
> 73,
> Ged.
>
> _______________________________________________
>
> clamav-users mailing list
> [email protected]
> https://lists.clamav.net/mailman/listinfo/clamav-users
>
>
> Help us build a comprehensive ClamAV guide:
> https://github.com/vrtadmin/clamav-faq
>
> http://www.clamav.net/contact.html#ml




_______________________________________________

clamav-users mailing list
[email protected]
https://lists.clamav.net/mailman/listinfo/clamav-users


Help us build a comprehensive ClamAV guide:
https://github.com/vrtadmin/clamav-faq

http://www.clamav.net/contact.html#ml
_______________________________________________

clamav-users mailing list
[email protected]
https://lists.clamav.net/mailman/listinfo/clamav-users


Help us build a comprehensive ClamAV guide:
https://github.com/vrtadmin/clamav-faq

http://www.clamav.net/contact.html#ml

Reply via email to