1. A system comprising: one or more computer-readable storage devices storing a data repository, the data repository comprising a plurality of different data collections; one or more computing devices comprising at least one or more memories and one or more processors; data server nodes, implemented at least partially by the one or more processors, configured to perform data operations on data collections, each particular data server node assigned to one or more data collections among the plurality of different data collections and configured to process messages by performing particular data operations on the one or more data collections to which the particular data server node is assigned; a message distribution component, implemented at least partially by the one or more processors, configured to receive particular messages, determine particular data collections of the plurality of different data collections that each particular message is associated with, and distribute the particular messages to particular data server nodes that are assigned to the associated particular data collections; a node creation component, implemented at least partially by the one or more processors, configured to, when a message of the particular messages is associated with one or more particular data collections to which none of the existing data server nodes are assigned, dynamically create a new data server node based on configuration data associated with the one or more particular data collections, assign the new data server node to the one or more particular data collections, and send the message to the new data server node, wherein the configuration data associated with the one or more particular data collections includes parameters that impact how the new data server node processes the one or more data collections.