redis_key does not return unique key

[stcheung]

I am relying on the default redis_key method in the 1.2.1 version to produce a unique key when the args is the same. In my case, the args is simply a single numeric id, such as 347. Poking into the code I realized that redis_key returns "Digest::MD5.hexdigest encode(:class => job, :args => args)". The problem with this is that the encode method would return a string where sometimes the :args parameter comes first, and sometimes the :class parameter comes first:

(1) "{"args":[347],"class""AsyncCallback"}"
(2) "{"class""AsyncCallback", "args":[347]}"

I can only reproduce it on a staging server (but not on development). Furthermore, within the same rails console I will always get the same version back. But when I restart the console then usually I can see the other version being returned. It seems to alternate but even if not, I can usually get the other version within a few console restarts.

I am using ruby 1.8.7 and Rails 3.0.19. I can overwrite the redis_key method in my class but I wonder if this is a generic issue that should be fixed in the plugin itself. Thanks.

[stcheung]

Upon further inspection and experimentation I realized it's because ultimately we are calling the "to_json" method on the hash and since 1.8.7 doesn't guarantee the key ordering, the resulting string can look different due to a different ordering of the keys.