1. A method of tracking data processing in an application carried out on a distributed computing system, the distributed computing system comprising a plurality of computing nodes connected for data communications through a data communications network, the application carried out by a plurality of pluggable processing components installed on the plurality of computing nodes, the pluggable processing components including a pluggable processing provider component and a pluggable processing consumer component, the method comprising: identifying, by the pluggable processing provider component, data satisfying predetermined processing criteria, the predetermined processing criteria specifying that the data is relevant to processing provided by the pluggable processing consumer component; passing, by the pluggable processing provider component, the data to the next pluggable processing component in the application for processing, including maintaining access to the data; receiving, by the pluggable processing consumer component, the data during execution of the application; and sending, by the pluggable processing consumer component, a receipt indicating that the pluggable processing consumer component received the data.