Came across this today on an app we are deploying across many servers. I was hashing some strings to store in a shared key/value store. The .hash method of String is returning different integers depending on the server. Any ideas why? Note that I am interested in why; not possible work arounds.
Example:
server1 $ ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
server1 $ irb
irb(main):001:0> "test".hash
=> 4146582576695053125
server2 $ ruby -v
ruby 1.9.2p180 (2011-02-18 revision 30909) [x86_64-linux]
server2 $ irb
"test".hash
=> 3479379392688537032
These machines are EC2 instances with the same specs and build.