[CentOS-mirror] Bandwidth questions

Wed Mar 23 19:31:06 UTC 2011
Simeon Berkley <sberkley at mcclatchyinteractive.com>

On 03/22/2011 12:24 PM, Jonathan Thurman wrote:
>> From: centos-mirror-bounces at centos.org [centos-mirror-bounces at centos.org] on behalf of Jim Kusznir
>
>> So do users have a suggestion on how to throttle / rate limit their
>> mirror server?  Mine sits on a gig-e connection, and I just got a call
>> from campus IT questioning the amount of bandwidth I'm using...Right
>> now, I'm running it "fully open", but I may have to restrict that, at
>> least during certain hours.  I run http, ftp, and rsync on my server.
>
> Rsync I haven't throttled bandwith usage, but have capped the max number of concurrent connections.  Unless someone is creating a fresh copy of the mirror, then rsync is rather efficient.  I also do not see a lot of users connecting over rsync.
>
> If you are using vsftp, then you could add something like this to your /etc/vsftp/vsftp.conf:
>
> # Max transfer rate 10 Mb
> anon_max_rate=10485760
>
...

We're running a ftp-only (so far) mirror that I'm about to announce to 
the list. It's my understanding that you need to adjust anon_max_rate 
*and* max_clients or else you could get, for example, 100 connections 
using a max transfer rate of 10Mb. So far I'm limiting our ftp 
connections/rate thusly:

anon_max_rate=5000000
max_clients=20

so that we can't get hit by over 100Mb of traffic. Please let me know if 
this doesn't sound right, or if 20 clients maximum is way too wimpy to 
be a useful mirror. Also, I'm assuming that since we're talking about 
network transfer rate, the rate doesn't need to be x(1024^2), just 
x(1000^2)?

I'm going to set the speed of the interface and the switch to 100, as a 
stopgap as well.

-- 
S i m e o n  B e r k l e y

Systems Engineer
Mcclatchy Interactive