[LINK] Green web servers with netbook components
grove at zeta.org.au
grove at zeta.org.au
Thu May 21 09:20:32 EST 2009
On Wed, 20 May 2009, Tom Worthington wrote:
> At 09:57 PM 19/05/2009, Bernard Robertson-Dunn wrote:
>> ... My experience of servers in data centres is that reliability and
>> availability are very important ...
> Reliability and availability can be provided by redundant servers,
> rather than servers with redundant components. That is you provide
> more than one server, so that if any of the components fail (power
> supply, disk, network connection or CPU) the other server takes over.
> This is the approach Google takes
> With this approach the design of the individual servers is much
> simpler, at the cost of increased complexity in the software. This
> also provides for the components to be geographically separated for
> another level of redundancy.
I architected a system like this, that has been going since 2005.
We call it "horizontal scaling". Each webserver is a Sun B100 blade
in a shelf with 3 such shelves in different geographical locations,
served behind a content switch.
Each blade contains:
1x 1Ghz CPU
Each blade runs a copy of Solaris in a rather lightweight mode. Just the
OS, no apps.
The web farm is mounted via NAS to a mountpoint that is shared amongst
all the blades. Every blade runs the same copy of the software/web
individually. we use apache vhosts to serve the farmed sites up.
Logging is done to local disk and processed via a merge script on a logserver.
I keep asking for "splunk" so I can get rid of my crappy scripts, but
the managers don't "get it".
The setup is extremely robust. The NAS is replicated so we can lose
a whole 2 datacentres and still serve the farm.
I am a big fan of horizontal scaling as a result. It will scale to
quite a huge setup. With reliance on a blade, rather than a
virtual zone, I can get a lot more processing power and page serves
out of each one.
> Tom Worthington FACS HLM tom.worthington at tomw.net.au Ph: 0419 496150
> Director, Tomw Communications Pty Ltd ABN: 17 088 714 309
> PO Box 13, Belconnen ACT 2617 http://www.tomw.net.au/
> Adjunct Senior Lecturer, Australian National University
> Link mailing list
> Link at mailman.anu.edu.au
Rachel Polanskis Kingswood, Greater Western Sydney, Australia
grove at zeta.org.au http://www.zeta.org.au/~grove/grove.html
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