Each Endeca data store is serviced by a Dgraph process.
The Dgraph uses proprietary data structures and algorithms that allow it to provide real-time responses to client requests. It stores the data files that were created from loading the data into it.
After the data files are stored, the Dgraph:
- receives client requests via the application tier,
- queries the data files,
- and returns the results.
The Dgraph is designed to be stateless. This design requires that a complete query be sent to it for each request. The stateless design facilitates the addition of Dgraph processes for load balancing and redundancy — any replica of a Dgraph can reply to queries independently of other replicas.
To get the status of the Dgraph, you have to get the status of the data store
In the data domain, more than one Dgraph process may be running. You can request the Dgraph stats page either on each Endeca Server node, or for all Dgraph instances at once.
The Dgraph stats page continues to be returned with http://host:port/endeca-server/admin/data_domain?op=stats for each machine hosting the Endeca Server for this data domain. In addition, endeca-cmd
endeca-cmd get-dd-status <data-domain>
returns the Dgraph node statistics for each running Dgraph node in the data domain (and not only for one Dgraph node).
When you create or attach an Endeca data store, you can optionally specify that its Dgraph process start with flags. These Dgraph flags allow you to adjust its configuration.
To obtain a listing of the Dgraph process arguments at the Oracle Endeca Server host and port, issue the create-ds or the attach-ds command with the –args –usage flag.
endeca-cmd create-ds --args --usage