STREAM BROWSER FOR DATA STREAMS

The described technology is generally directed towards a stream browser that provides a human-readable (e.g., hierarchical) view of event data for a data stream of a data streaming storage service. A stream browser associated with a data stream maintains routing key and event data for the data stream, e.g., in a primary index. The routing keys can correspond to container structures, e.g., folders and subfolders, with the events associated with each routing key corresponding to hierarchical children of the routing key parent container structures (e.g., like files). A secondary index can be used to evict the oldest events from the primary index to limit the number of data stream events returnable by the stream browser to a practical number.