20. GeoMesa NiFi Bundle¶
NiFi manages large batches and streams of files and data. GeoMesa-NiFi allows you to ingest data into GeoMesa straight from NiFi by leveraging custom processors.
20.1. Installation¶
20.1.1. Build and Install the Processors¶
Clone the project from GitHub. Pick a reasonable directory on your machine, and run:
$ git clone https://github.com/geomesa/geomesa-nifi.git
$ cd geomesa-nifi
To build the project, run
$ mvn clean install
To install the GeoMesa processors you will need to copy the
geomesa-nifi-nar file from
geomesa-nifi/geomesa-nifi-nar/target/geomesa-nifi-nar-$VERSION.nar
into the lib/ directory of your NiFi installation.
20.1.2. Install the SFTs and Converters¶
The GeoMesa processors need access to SimpleFeatureTypes and converters in order
to ingest data. There are two ways of providing these to the processors.
We can enter the SFT specification string and converter specification
string directly in a processor or we can provide these to the processors
by placing the SFTs and converters in a file named reference.conf
and then putting that file on the classpath. This can be achieved by
wrapping this file in a JAR and placing it in the lib/ directory of
the NiFi installation. For example you can wrap the reference.conf
file in a JAR with this command.
$ jar cvf data-formats.jar reference.conf
To validate everything is correct, run this command. Your results should be similar.
$ jar tvf data-formats.jar
0 Mon Mar 20 18:18:36 EDT 2017 META-INF/
69 Mon Mar 20 18:18:36 EDT 2017 META-INF/MANIFEST.MF
28473 Mon Mar 20 14:49:54 EDT 2017 reference.conf
20.2. Processors¶
GeoMesa NiFi contains several processors:
| Processor | Description |
|---|---|
PutGeoMesaAccumulo |
Ingest data into a GeoMesa Accumulo datastore with a GeoMesa converter or from geoavro |
PutGeoMesaHBase |
Ingest data into a GeoMesa HBase datastore with a GeoMesa converter or from geoavro |
PutGeoMesaFileSystem |
Ingest data into a GeoMesa File System datastore with a GeoMesa converter or from geoavro |
PutGeoMesaKafka |
Ingest data into a GeoMesa Kafka datastore with a GeoMesa converter or from geoavro |
PutGeoTools |
Ingest data into an arbitrary GeoTools datastore using a GeoMesa converter or avro |
ConvertToGeoAvro |
Use a GeoMesa converter to create geoavro |
20.2.1. Input Configuration¶
Most of the processors accept similar configuration parameters for specifying the input source. Each datastore-specific processor also has additional parameters for connecting to the datastore, detailed in the following sections.
| Property | Description |
|---|---|
| Mode | Converter or Avro file ingest mode switch. |
| SftName | Name of the SFT on the classpath to use. This property overrides SftSpec. |
| ConverterName | Name of converter on the classpath to use. This property overrides ConverterSpec. |
| FeatureNameOverride | Override the feature name on ingest. |
| SftSpec | SFT specification String. Overwritten by SftName if SftName is valid. |
| ConverterSpec | Converter specification string. Overwritten by ConverterName if ConverterName is valid. |
20.2.2. PutGeoMesaAccumulo¶
The PutGeoMesaAccumulo processor is used for ingesting data into an Accumulo-backed GeoMesa datastore. To use
this processor, first add it to the workspace and open the properties tab of its configuration. For a description
of the connection properties, see Accumulo Data Store Parameters.
20.2.2.1. GeoMesa Configuration Service¶
The PutGeoMesaAccumulo plugin supports NiFi Controller
Services
to manage common configurations. This allows the user to specify a
single location to store the Accumulo connection parameters. This allows
you to add new PutGeoMesaAccumulo processors without having to enter duplicate
data.
To add the GeomesaConfigControllerService access the
Contoller Settings from NiFi global menu and navigate to the
ControllerServices tab and click the + to add a new service.
Search for the GeomesaConfigControllerService and click add. Edit
the new service and enter the appropriate values for the properties
listed.
To use this feature, after configuring the service, select the
appropriate Geomesa Config Controller Service from the drop down of the
GeoMesa Configuration Service property. When a controller service is
selected, the standard connection parameters (i.e. zookeeper, instance ID, etc)
are not required or used.
20.2.3. PutGeoMesaHBase¶
The PutGeoMesaHBase processor is used for ingesting data into an HBase-backed GeoMesa datastore. To use
this processor, first add it to the workspace and open the properties tab of its configuration. For a description
of the connection properties, see HBase Data Store Parameters.
20.2.4. PutGeoMesaFileSystem¶
The PutGeoMesaFileSystem processor is used for ingesting data into a file system-backed GeoMesa datastore. To use
this processor, first add it to the workspace and open the properties tab of its configuration. For a description
of the connection properties, see FileSystem Data Store Parameters.
20.2.5. PutGeoMesaKafka¶
The PutGeoMesaKafka processor is used for ingesting data into a
Kafka-backed GeoMesa datastore. This processor supports Kafka 0.9
and newer. To use this processor first add it to the workspace and open
the properties tab of its configuration. For a description
of the connection properties, see Kafka Data Store Parameters.
20.2.6. PutGeoTools¶
The PutGeoTools processor is used for ingesting data into any GeoTools
compatible datastore. To use this processor first add it to the
workspace and open the properties tab of its configuration.
| Property | Description |
|---|---|
| DataStoreName | Name of the datastore to ingest data into. |
This processor also accepts dynamic parameters that may be needed for the specific datastore that you’re trying to access.
20.2.7. ConvertToGeoAvro¶
The ConvertToGeoAvro processor leverages GeoMesa’s internal
converter framework to convert features into Avro and pass them along as
a flow to be used by other processors in NiFi. To use this processor
first add it to the workspace and open the properties tab of its
configuration.
| Property | Description |
|---|---|
| OutputFormat | Only Avro is supported at this time. |
20.3. NiFi User Notes¶
NiFi allows you to ingest data into GeoMesa from every source GeoMesa supports and more. Some of these sources can be tricky to setup and configure. Here we detail some of the problems we’ve encountered and how to resolve them.
20.3.1. GetHDFS Processor with Azure Integration¶
It is possible to use the Hadoop Azure
Support
to access Azure Blob Storage using HDFS. You can leverage this
capability to have the GetHDFS processor pull data directly from the
Azure Blob store. However, due to how the GetHDFS processor was written,
the fs.defaultFS configuration property is always used when
accessing wasb:// URIs. This means that the wasb:// container
you want the GetHDFS processor to connect to must be hard coded in the
HDFS core-site.xml config. This causes two problems. Firstly, it
implies that we can only connect to one container in one account on
Azure. Secondly, it causes problems when using NiFi on a server that is
also running GeoMesa-Accumulo as the fs.defaultFS property needs to
be set to the proper HDFS master NameNode.
There are two ways to circumvent this problem. You can maintain a
core-site.xml file for each container you want to access but this is
not easily scalable or maintainable in the long run. The better option
is to leave the default fs.defaultFS value in the HDFS
core-site.xml file. We can then leverage the
Hadoop Configuration Resources property in the GetHDFS processor.
Normally you would set the Hadoop Configuration Resources property
to the location of the core-site.xml and the hdfs-site.xml
files. Instead we are going to create an additional file and include it
last in the path so that it overwrites the value of the fs.defaultFS
when the configuration object is built. To do this simply create a new
xml file with an appropriate name (we suggest the name of the
container). Insert the fs.defaultFS property into the file and set
the value.
<configuration>
<property>
<name>fs.defaultFS</name>
<value>wasb://container@accountName.blob.core.windows.net/</value>
</property>
</configuration>
20.4. Reference¶
For more information on setting up or using NiFi see the Apache NiFi User Guide