21.3. Using the Lambda Data Store Programmatically

21.3.1. 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.

21.3.2. 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.