1. A distributed data repository node allowing for content-based data storage and retrieval, comprising a network interface operative to communicate with client nodes and at least one other distributed data repository node over a computer network, wherein client nodes transmit messages including message payloads; a content-based filter layer operative to receive the message payloads transmitted by the client nodes; apply at least one content-based filter to the message payloads received by the client nodes to extract one or more content attribute values corresponding to respective content attributes defined in the at least one content-based filter; a memory that stores a content map and at least one index map corresponding to an attribute; and a mapping module operative to receive, from the content-based filter layer, the message payloads and the extracted one or more content attribute values, store the message payloads received from the content-based filter layer in the content map in association with unique identifiers, store the one or more content attribute values associated with the message payloads received from the content-based filter layer in the at least one index map; synchronize the one or more content attribute values in the at least one index map with the at least one other distributed data repository node; receive a query including one or more attribute values each corresponding to a respective attribute; determine one or more unique identifiers for message payloads that match the query, the determining using one or more index maps associated with one or more attributes that correspond to the one or more attribute values; identify message payloads in the content map using the one or more unique identifiers; and return the identified message payloads in response to the query.