1. A hot-update method, comprising: obtaining, in response to receiving a hot-update instruction by a running program, an update assembly and difference descriptions for describing differences between the update assembly and an existing assembly of the running program, wherein, identical metadata in said update assembly and said existing assembly have identical identifiers; loading said update assembly into memory, and finding, in said update assembly, functions which have been modified with respect to the existing assembly according to said difference descriptions; performing just-in-time compilation to the modified functions which have been found to obtain update native code; and running said update native code in place of corresponding existing native code of said modified functions when said existing native code is required to be run.