Discovering the correct dataset efficiently is critical for computations and effective simulations in scientific experiments. In contrast to searching web documents over the Internet, massive binary datasets are difficult to browse or search. Users must select a reliable data publisher from the large collection of data services available over the Internet. Once a publisher is selected, the user must then discover the dataset that matches the computation's needs, among tens of thousands of large data packages that are available. Some of the data hosting services provide advanced data search interfaces but their search scope is often limited to local datasets. Because scientific datasets are often encoded as binary data formats, querying or validating missing data over hundreds of Megabytes of a binary file involves a compute intensive decoding process. We have developed a system, GLEAN, that provides an efficient data discovery environment for users in scientific computing. Fine-gr...