Archive for January, 2009

iMob brings down GeoNames, other iPhone apps

Thursday, January 22nd, 2009

A lot of iPhone applications need to convert a user’s location from the latitude/longitude that the iPhone SDK returns into a postal code. This is primarily because a lot of APIs still use postal codes to look up information. This is the case for Hot Popcorn where we look up movie times using either a postal code or city, state.

The popular choice for doing this conversion is GeoNames, a web service run by Marc Wick free of charge under a creative commons attribution license. When an API is free, there have to be limits to set to prevent abuse. GeoNames limits usage in it’s terms of service to 50,000 requests per IP address per day.

But this is a new world with rich clients like the iPhone, each with their own IP addreess. So what happens when a free popular iPhone game like iMob uses GeoNames? Mayhem.

iMob Online is currently #5 in the Top Free Apps on iTunes and this has essentially brought down GeoNames:

The problem since yesterday evening is an enormously popular iphone application called iMob. It is hammering the server with > 100 requests per second which has the effect of a DDOS attack. I am trying to get in touch with the developers to have them remove this feature from their application.

This forced Marc to take down the server:

We have temporarily removed the domain ws.geonames.org from the dns setting to protect the server from exessive use by an iphone application. You can access the server with the domain ws5.geonames.org

Now any iPhone application trying to use GeoNames will fail. Thanks iMob!