13.3. Using the Lambda Data Store Programmatically¶
13.3.1. Creating a Data Store¶
An instance of a Lambda data store can be obtained through the normal GeoTools discovery methods, assuming that the GeoMesa code is on the classpath:
Map<String, String> parameters = new HashMap<>;
parameters.put("lambda.accumulo.instance.id", "myInstance");
parameters.put("lambda.accumulo.zookeepers", "zoo1,zoo2,zoo3");
parameters.put("lambda.accumulo.user", "myUser");
parameters.put("lambda.accumulo.password", "myPassword");
parameters.put("lambda.accumulo.tableName", "my_table");
parameters.put("lambda.kafka.brokers", "kafka1:9092,kafka2:9092");
parameters.put("lambda.kafka.zookeepers", "zoo1,zoo2,zoo3");
parameters.put("lambda.expiry", "10 minutes");
org.geotools.data.DataStore dataStore = org.geotools.data.DataStoreFinder.getDataStore(parameters);
More information on using GeoTools can be found in the GeoTools user guide.
13.3.2. Lambda Data Store Parameters¶
The data store takes several parameters (required parameters are marked with *):
| Parameter | Type | Description |
|---|---|---|
lambda.accumulo.instance.id * |
String | The instance ID of the Accumulo installation |
lambda.accumulo.zookeepers * |
String | A comma separated list of zookeeper servers (e.g. “zoo1,zoo2,zoo3” or “localhost:2181”) |
lambda.accumulo.catalog * |
String | The name of the GeoMesa catalog table |
lambda.accumulo.user * |
String | Accumulo username |
lambda.accumulo.password |
String | Accumulo password |
lambda.accumulo.keytab.path |
String | Path to a Kerberos keytab file containing an entry for the specified user |
lambda.accumulo.mock |
Boolean | Use a mock connection (for testing) |
lambda.kafka.brokers * |
String | A comma separated list of kafka brokers (e.g. broker1:9092,broker2:9092) |
lambda.kafka.zookeepers * |
String | A comma separated list of zookeeper servers (e.g. zoo1,zoo2,zoo3 or localhost:2181) |
lambda.kafka.partitions |
Integer | Number of partitions used to create new topics. You should generally set this to the number of writer instances you plan to run |
lambda.kafka.consumers |
Integer | Number of consumers used to load data into the in-memory cache |
lambda.kafka.producer.options |
String | Java-properties-formatted string that is passed directly to the Kafka producer. See Producer Configs |
lambda.kafka.consumer.options |
String | Java-properties-formatted string that is passed directly to the Kafka consumer. See New Consumer Configs |
lambda.expiry * |
String | A duration for how long features are kept in memory before being persisted (e.g. 10 minutes).
Using Inf will cause the data store to not participate in persisting expired entries |
lambda.persist |
Boolean | Whether expired features should be persisted to Accumulo or just discarded |
geomesa.security.auths |
String | Comma-delimited superset of authorizations that will be used for queries via Accumulo |
geomesa.security.force-empty-auths |
Boolean | Forces authorizations to be empty |
geomesa.security.auth-provider |
String | Class name for an AuthorizationsProvider implementation |
geomesa.security.visibilities |
String | Visibilities to apply to all written data |
geomesa.query.audit |
Boolean | Audit queries being run. Queries will be stored in a <catalog>_queries table |
geomesa.query.timeout |
String | The max time a query will be allowed to run before being killed. The
timeout is specified as a duration, e.g. 1 minute or 60 seconds |
geomesa.query.threads |
Integer | The number of threads to use per query |
geomesa.query.loose-bounding-box |
Boolean | Use loose bounding boxes - queries will be faster but may return extraneous results |
accumulo.query.record-threads |
Integer | The number of threads to use for record retrieval |
accumulo.write.threads |
Integer | The number of threads to use for writing records |
geomesa.stats.generate |
Boolean | Toggle collection of statistics |
geomesa.query.caching |
Boolean | Toggle caching of results |
Note: one (but not both) of lambda.accumulo.password and lambda.accumulo.keytab.path must be provided.