1. A method for processing inputs comprising: providing a plurality of rules engines, wherein each of the plurality of rules engines is written in a different programming language; performing input validation processing of a first set of one or more inputs by a first of the plurality of rules engines using a first portion of validation rules, wherein said first set of one or more inputs are user inputs obtained from a user interface and in connection with provisioning storage for a logical entity in a data storage system, wherein each of the validation rules includes a message identifier associated with an error message, and each of the validation rules includes validation criteria comprising required validation criteria and optionally comprising optional validation criteria, wherein a specified input needs to meet the required criteria and additionally needs to meet the optional validation criteria, if specified, to be successfully validated in accordance with said each validation rule, wherein said optional validation criteria of at least one of the validation rules includes any of: a minimum length of an input, a maximum length of an input, and an expression denoting an acceptable pattern or format of an input, wherein a plurality of message catalogues include text of a same set of error messages for a plurality of spoken languages, the plurality of message catalogues each using a same set of message identifiers whereby a same one of the message identifiers in each of the plurality of message catalogues is associated with text of a same error message in a different one of the plurality of spoken languages; and responsive to the input validation processing by the first rules engine determining that the first set of one or more inputs is valid, performing processing including: transforming at least one of the first set of one or more inputs and producing a second set of one or more inputs as a result of said transforming; and performing input validation processing of the second set of one or more inputs by a second of the plurality of rules engines using the second portion of the validation rules.