From mboxrd@z Thu Jan 1 00:00:00 1970 From: Szymon Miotk Date: Fri, 03 Jun 2005 06:37:30 +0000 Subject: Re: [LARTC] How many (htb) tc classes and qdiscs are too many? Message-Id: <429FFAAA.2070406@crocom.com.pl> List-Id: References: <000501c567bf$792fd700$650fa8c0@hotsitespencer> In-Reply-To: <000501c567bf$792fd700$650fa8c0@hotsitespencer> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lartc@vger.kernel.org Spencer wrote: > We have a Linux box that is acting as the gateway to the internet for about > 400 people, typically there are not more then 50 of them using the internet > at any given time. We would like to provide different levels of access to > different users. For example 128kbps to some users and 256kbps to others. > We have considered creating a class and qdisc for each user (using htb) > however we don't know how much overhead creating 50-200 classes and > qdiscs would involve, would this put too much strain on the Linux box? Is > it > better to create fewer classes and qdisc and assign multiple users to each? > I haven't been able to find any test on maximum effect number of qdiscs, but > it could be I have just been looking in the wrong place. If any one has any > ideas or could point me in the right direction it would be greatly > appreciated. I have P4 3.0 GHz, 1 GB RAM. I have 3500 potential users (top load about 800 users, average 400). I have 3 interfaces (2 WAN + 1 LAN), so I have 10500 queues total (3500 on each interface). The traffic is 24Mbit max, average 20Mbit. Without u32 hashing my box run at 60-70% CPU utilization. After applying hashing the box is running with 25% top utilization, average 15%. The two thing you must remember when running a box for many users: * use iptables chains. I prefer chains of 30-40 entries. * use u32 hashing. This will greatly improve CPU utilization. About 500-1000% in my case. Szymon Miotk _______________________________________________ LARTC mailing list LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/cgi-bin/mailman/listinfo/lartc