Reach Isles :: luxury living in Second Life®

Musings on SL geolocation

May 28, 2009 by reacher · Leave a Comment 

Taking a departure from blogging on land topics, I thought I’d share some thoughts on computer networks that might help those of you who are planning to setup webservers for your Second Life business applications. What I mean by this is, webservers that communicate with scripted prims inside of SL, and vice versa. A common use is to have a scripted prim in-world communicate with a web-enabled database out of world, via XML-RPC and/or HTTP.

At Reach Isles we use this technology to keep track of data gathered in-world, such as visitors to our land parcels for sale. It is also the foundation for the ATM-like payment system we are working on, that will allow our customers to pay their tiers in-world from a kiosk. The interface remains in-world, but the actual data is stored safely out of world on our server’s database.

The importance of geolocation:

If you’re considering setting up a similar server, and want it to be highly available and reliable, you probably want to rent server space at a hosting facility, which offers benefits like climate control, uninterruptable power, and a redundant network backbone to draw upon. i.e, don’t store the server in your basement. ;) So then the question becomes, who to rent from? A natural choice might be to choose a provider in your local area, but that might not be the most logical choice. Consider instead who will be using the server – avatars inside SL, via the scripted prims you’ve setup on your sim there. While the people behind the avatars come from all over the world, the SL simulators do not. They are stored in datacenters in Dallas, TX, with a smaller subset in Phoenix, AZ. What matters is the exchange of data between the simulators and webserver. Thus storing the webserver close to the sims will make your scripted applications faster and more reliable when they need to interact with the server out of world.

So a server hosted in Dallas is obviously a great choice, as would be any nearby location.The less distance your data has to travel over the Internet, the faster the applications will work, and they will also be less prone to network outages on the Internet which may sever the connection between your webserver and Second Life sim. Our webserver is hosted with ServerBeach, whose service and prices are great, but more importantly they offer a free choice of datacenters around the United States, including one in San Antonio, TX, just a short hop away from Dallas.

We can use a software tool called ping to trace the round-trip time of network packets from our server to one of our SL sims.

$ ping
PING ( 56(84) bytes of data.
64 bytes from ( icmp_seq=1 ttl=58 time=8.24 ms
64 bytes from ( icmp_seq=2 ttl=58 time=8.28 ms
64 bytes from ( icmp_seq=3 ttl=58 time=8.14 ms
64 bytes from ( icmp_seq=4 ttl=58 time=8.08 ms
64 bytes from ( icmp_seq=5 ttl=58 time=8.02 ms
--- ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 8.024/8.156/8.287/0.138 ms

What this shows is that it takes only about 8 milliseconds for a packet to travel over the Internet from our server to a sim and back, which is incredibly fast. It takes about 17 times longer to communicate with a server in London, and 40 times longer for a server in Sydney, Australia. Not to mention the additional physical distance – any network trouble or outages between Dallas and those locations will cause trouble for your in-world applications, and thus your users.


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Reach Isles :: luxury living in Second Life®