17 Sep 08 95th percentile billing explaination

95th percentile billing commonly misspelled as “percential” is a method used by some NOCs to change for bandwidth.

The system is simple and essentially discards the top 5% of your traffic peaks, and then uses the next value down as your bandwidth rate. 5% of a month is 36 hours. This might sound like a bit of a scam, because you’re being billed for bandwidth consumption that you may not have used, but it’s not difficult to get it to work for you.

If you’re hosting a site where a lot of content is downloaded, it may be better to go for bandwidth billing. A client’s content server uses about 8,000GB transfer per month and shows a 95th percentile of 34mbit/sec. It’s certainly cheaper to pay for 8,000GB transfer over 30+mbit/sec dedicated.
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Tags: 95th, 95th percential, 95th percentile, bandwidth consumption, bandwidth management, bandwidth rate, burst, content, datacenter, download, hosting, limiting, noc, peak, peaks, servers, shaping, traffic, traffic peaks

14 Sep 08 Linux virtualization, vmware, xen, hosting, and squeezing the most out of your resources

I’d guess that 90% of hosting providers ‘oversell’. This essentially means that should they have 1,000GB allocated, they might offer 15 packages of 100Gb to 15 of their customers, banking on the fact that no one will fully use their 100GB allocation - Selling 5 Virtual Machines with 256MB RAM on a 1GB host, assuming that no one will use their full RAM allocation. This is bad, because you’ll generally be able to confirm that you’ve been allocated the resources, but nonetheless benchmark tests will show that you’re just not getting them, and your environment will be sluggish and unresponsive. This is the same as airlines selling 110 seats on a 100 seat plane. When that 101st paying customer does show up to claim his seat, he’s stuck without a flight.

The general consensus is that a VPS is a cheaper and lower-grade option than a dedicated service, however VPSs have a number of undisputable advantages over dedicated servers and I’m going to discuss why almost all the dedicated machines I manage are hosts for a range of VPSs.
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Tags: 10mbit, adamsinfo.com, advantages, allocation, apache2, backup service, benchmark, bind, cheap, client, co-locate, colocate, config, CPU, datacenter, debian, dedicated, dedicated servers, disk access, disk IO, endpoint, environment, exim, host, hosting, hosting providers, Intel, kernel, kernel upgrade, mailserver, mppc, mppe, MySQL, named, noc, oversell, packages, php5, pptp, processor type, Quad Core, racks, reboot, remote services, routing, seek time, spamassassin, system administrator, tick speed, virtualization, vmware, vmware free server, vmware gsx, VPN, vps, xen, Xeon

02 Jul 08 Bandwidth Limiting HOWTO with linux, tc and iproute2

I’ve recently optimized the scripts used for bandwidth management in one of our UK facilities and I thought I’d post a quick howto on it.

Discuss this page here

My setup here is a live feed entering eth0 on this linux router and leaving eth1 into a switch connected to a collection of other servers. This is set up as an unrestricted public router, routing between a /30 on eth0 and a /24 on eth1.
Note: We can’t in any way restrict the amount of traffic that eth0 receives from the outside, so instead we restrict how fast eth0 sends data out, the same applies the other way round. So, if we want to limit the amount of data that the local servers can send, we shape the router’s external interface (eth0). If we want to limit the amount of data that the local servers can receive, we shape the router’s internal interface (eth1)
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Tags: 100mbit, 10mbit, 95th percential, 95th percentile, Add new tag, apt-get, bandwidth management, bmon, bulk, classes, datacenter, debian, external interface, htb, interactive, internal interface, iproute2, Linux, percentile, priority, qdisc, restrict traffic, router, routing, switch, tc, traffic shaping