10. The machine-readable storage medium of claim 9 , wherein at least the index update event and updating the local copy of the search index are performed asynchronously.
9. A machine-readable storage medium having instructions stored therein, which when executed by a machine, cause the machine to perform a method, the method comprising: receiving, at a query and retrieval application programming interface (API) of a data processing system, a full text search query from a client, the data processing system including a master search node and a plurality of slave search nodes that are communicatively coupled to the master search node, each of the slave search nodes maintaining a local copy of a search index that is derived from a master search index of an index directory maintained by the master search node, wherein each of the slave and master search nodes is configured to perform a search in a relational database independently; forwarding, via a first process thread, the search query to a local copy of the search index by a first slave search node, to perform a search of the relational database during a search session; returning to the client, by the first slave search node, a list of objects retrieved from the relational database that contain at least one search term of the search query; in response to receiving a list of updated data entries of the relational database from the client through the query and and retrieval API, the first slave search node scheduling, via a second process thread, an index update event to update the master search index of the index directory of the master search node, wherein the index update event is triggered when the list of updated data entries is committed to the relational database, the index update event causing the master search index to be updated based on the list of updated data entries; and periodically updating, by the first slave node via a third process thread, the local copy of the search index by copying index data from the master search index of the index directory of the master search node to the local copy of the search index of the first slave node.