102. A searchable data service node, comprising: one or more processors; a network interface configured to communicatively couple to a network; and a memory comprising program instructions, wherein the program instructions are executable by the one or more processors to: receive via the network searchable data service requests from a plurality of client applications in accordance with a web service interface, wherein the searchable data service requests comprise query requests, and wherein the web service interface provides a common message endpoint to the plurality of client applications to send the query requests; locate sets of one or more searchable data service objects in respective searchable indexes for a plurality of independent data stores used by the client applications that satisfy received query requests, wherein the query requests specify one of the searchable indexes, wherein the searchable indexes are distributed on a plurality of searchable data service nodes on the network, wherein the data stores are on one or more storage devices each on the network and separate from computer devices on the network that implement the searchable data service nodes, wherein each searchable index stores searchable data service objects for a particular one of the plurality of independent data stores such that each searchable index provides a complete index for only one of the independent data stores, wherein each searchable data service object specifies two or more attributes of a particular entity in a particular data store, and wherein the attributes include a unique entity identifier for locating the particular entity in the particular data store; and return via the network at least the entity identifiers from the sets of one or more searchable data service objects that satisfy the query requests to the client applications in accordance with the web service interface.
102. A searchable data service node, comprising: one or more processors; a network interface configured to communicatively couple to a network; and a memory comprising program instructions, wherein the program instructions are executable by the one or more processors to: receive via the network searchable data service requests from a plurality of client applications in accordance with a web service interface, wherein the searchable data service requests comprise query requests, and wherein the web service interface provides a common message endpoint to the plurality of client applications to send the query requests; locate sets of one or more searchable data service objects in respective searchable indexes for a plurality of independent data stores used by the client applications that satisfy received query requests, wherein the query requests specify one of the searchable indexes, wherein the searchable indexes are distributed on a plurality of searchable data service nodes on the network, wherein the data stores are on one or more storage devices each on the network and separate from computer devices on the network that implement the searchable data service nodes, wherein each searchable index stores searchable data service objects for a particular one of the plurality of independent data stores such that each searchable index provides a complete index for only one of the independent data stores, wherein each searchable data service object specifies two or more attributes of a particular entity in a particular data store, and wherein the attributes include a unique entity identifier for locating the particular entity in the particular data store; and return via the network at least the entity identifiers from the sets of one or more searchable data service objects that satisfy the query requests to the client applications in accordance with the web service interface. 105. The searchable data service node as recited in claim 102 , wherein each attribute is expressed as a {name, value} pair.