A method for processing data includes receiving an adjustment request for adjusting a number of consumer instances from a first number to a second number, and determining a migration overhead for adjusting a first distribution of states associated with the first number of consumer instances to a second distribution of the states associated with the second number of consumer instances, wherein the states are intermediate results of processing the data and the migration overhead includes a latency and a bandwidth shortage incurred for migrating the states. Based on the determined migration overhead, the states are migrated between the first number of consumer instances and the second number of consumer instances, and thereafter the data is processed based on the second distribution of the states at the second number of consumer instances.