Embodiments of the present disclosure relates to data block processing in a distributed processing system. According to one embodiment of the present disclosure, a computer-implemented method is proposed. A first performance indicator for processing a data block by a first processing module is obtained, where the data block is loaded into the first processing module. Then, a second performance indicator for processing the data block by a second processing module is obtained, where the first and second processing modules being logical instances launched in a distributed processing system for processing data blocks. Next, one processing module is selected from the first and second processing modules for processing the data block based on a relationship between the first and second performance indicators.