Merge pull request #414 from jason-fox/patch-3

Add Database Indexes

docker/README.md

@@ -221,3 +221,27 @@ than 100 GB RAM, you will want to increase this value to match the available RAM
 
 If you want to get more details about the configuration of the system and node.js for high performance scenarios, please
 refer to the [Installation Guide](https://fiware-iotagent-ul.rtfd.io/en/latest/installationguide/index.html).
+
+### Set-up appropriate Database Indexes
+
+If using Mongo-DB as a data persistence mechanism (i.e. if `IOTA_REGISTRY_TYPE=mongodb`) the device and service group
+details are retrieved from a database. The default name of the IoT Agent database is `iotagentul`. Database access can be
+optimized by creating appropriate indices.
+
+For example: 
+
+```console
+docker exec  <mongo-db-container-name> mongo --eval '
+	conn = new Mongo();
+	db = conn.getDB("iotagentul");
+	db.createCollection("devices");
+	db.devices.createIndex({"_id.service": 1, "_id.id": 1, "_id.type": 1});
+	db.devices.createIndex({"_id.type": 1}); 
+	db.devices.createIndex({"_id.id": 1});
+	db.createCollection("groups");
+	db.groups.createIndex({"_id.resource": 1, "_id.apikey": 1, "_id.service": 1});
+	db.groups.createIndex({"_id.type": 1});' > /dev/null
+```
+
+The name of the database can be altered using the `IOTA_MONGO_DB` environment variable. Alter the `conn.getDB()` 
+statement above if an alternative database is being used.