While making a cfhttp call to a coldfusion server the apache httpclient library tries to generate a secure random number. It is an operation which depends on the "entropy" of the system.
In case of linux systems (mainly the ones which are freshly installed) it is observed that this operation can be quite time consuming because the system "entropy" is apparently quite low. Hence, as a consequence cfhttp calls will be slow.
Source: http://blogs.coldfusion.com/post.cfm/optimizing-cfhttp-calls-on-linux-systems
Solution: Add “-Djava.security.egd=file:/dev/./urandom”
to your jvm-setting.
In the Adobe Forums, you find another thread with your problem and the same solution and a following link with further informations about the random number generator: http://forums.adobe.com/thread/1063806
There is no need for not using /dev/urandom as it is a secure solution: https://security.stackexchange.com/a/3939