Techniques and tools are described for matching documents against monitors. An index can be generated from a plurality of monitors, where the index represents the query logic of the plurality of monitors. The index can be searched using the documents as search queries. The searching can comprise matching the documents against the monitors using the query logic represented in the index. An index can be distributed to a plurality of computing devices to be searched at the plurality of computing devices, where each computing device searches a subset of a plurality of documents against the full index. Searching at the plurality of computing devices can be performed in parallel, and results can be aggregated at a central location.