1. A computer implemented method for improved clustering of analytic functions in a data processing environment, the computer implemented method comprising: identifying a set of instances of an analytic function receiving data input from a set of data sources, a first subset of instances configured to receive input from a first subset of data sources, and a second subset of instances configured to receive input from a second subset of data sources, wherein the analytic function is described by an analytic function specification, an instance in the set of instances executing in the data processing environment, and wherein the analytic function performs an analytical computation when the instance executes in the data processing environment; assigning the set of instances to a cluster, wherein the cluster is a process within which the set of instances are configured to execute, and wherein the instances in the set of instances satisfy a condition; and beginning executing the cluster in a computer in the data processing environment when the first subset of data sources begins transmitting time series data input to the first subset of instances in the cluster.