16.1. Installing GeoMesa Cassandra¶

Note

GeoMesa currently supports Cassandra version 3.

Note

The examples below expect a version to be set in the environment:

$ export TAG="5.1.0"
$ export VERSION="2.12-${TAG}" # note: 2.12 is the Scala build version

16.1.1. Connecting to Cassandra¶

The first step to getting started with Cassandra and GeoMesa is to install Cassandra itself. You can find good directions for downloading and installing Cassandra online. For example, see Cassandra’s official getting started documentation.

Once you have Cassandra installed, the next step is to prepare your Cassandra installation to integrate with GeoMesa. First, create a key space within Cassandra. The easiest way to do this with cqlsh, which should have been installed as part of your Cassandra installation. Start cqlsh, then type:

CREATE KEYSPACE mykeyspace WITH REPLICATION = {'class': 'SimpleStrategy', 'replication_factor' : 3};

This creates a key space called “mykeyspace”. This is a top-level name space within Cassandra and it will provide a place for GeoMesa to put all of its data, including data for spatial features and associated metadata.

Next, you’ll need to set the CASSANDRA_HOME environment variable. GeoMesa uses this variable to find the Cassandra jars. These jars should be in the lib directory of your Cassandra installation. To set the variable add the following line to your .profile or .bashrc file:

export CASSANDRA_HOME=/path/to/cassandra

Finally, make sure you know a contact point for your Cassandra instance. If you are just trying things locally, and using the default Cassandra settings, the contact point would be 127.0.0.1:9042. You can check and configure the port you are using using the native_transport_port in the Cassandra configuration file (located at conf/cassandra.yaml in your Cassandra installation directory).

16.1.2. Installing from the Binary Distribution¶

GeoMesa Cassandra artifacts are available for download or can be built from source. The easiest way to get started is to download the most recent binary version from GitHub.

Download and extract it somewhere convenient:

# download and unpackage the most recent distribution:
$ wget "https://github.com/locationtech/geomesa/releases/download/geomesa-${TAG}/geomesa-cassandra_${VERSION}-bin.tar.gz"
$ tar xvf geomesa-cassandra_${VERSION}-bin.tar.gz
$ cd geomesa-cassandra_${VERSION}

16.1.3. Building from Source¶

GeoMesa Cassandra may also be built from source. For more information, refer to the instructions on GitHub. The remainder of the instructions in this chapter assume the use of the binary GeoMesa Cassandra distribution. If you have built from source, the distribution is created in the target directory of geomesa-cassandra/geomesa-cassandra-dist.

16.1.4. Setting up the Cassandra Command Line Tools¶

GeoMesa Cassandra comes with a set of command line tools for managing Cassandra features located in geomesa-cassandra_${VERSION}/bin/ of the binary distribution.

Note

You can configure environment variables and classpath settings in geomesa-cassandra_${VERSION}/conf/*-env.sh.

Note

geomesa-cassandra will read the $CASSANDRA_HOME and $HADOOP_HOME environment variables to load the appropriate JAR files for Cassandra and Hadoop. In addition, geomesa-cassandra will pull any additional JARs from the $GEOMESA_EXTRA_CLASSPATHS environment variable into the class path. Use the geomesa-cassandra classpath command in order to see what JARs are being used.

If you do not have a local Cassandra installation, the first time you run the tools it will prompt you to download the necessary JARs. You may also do this manually using the scripts provided with the distribution:

$ ./bin/install-dependencies.sh

Due to licensing restrictions, dependencies for shape file support must be separately installed. Do this with the following command:

$ ./bin/install-shapefile-support.sh

Run geomesa-cassandra without arguments to confirm that the tools work.

$ bin/geomesa-cassandra

The output should look like this:

INFO  Usage: geomesa-cassandra [command] [command options]
  Commands:
  ...

16.1.5. Installing GeoMesa Cassandra in GeoServer¶

Warning

See GeoServer Versions to ensure that GeoServer is compatible with your GeoMesa version.

The GeoMesa Cassandra distribution includes a GeoServer plugin for including Cassandra data stores in GeoServer. The plugin files are in the dist/gs-plugins/geomesa-cassandra-gs-plugin_${VERSION}-install.tar.gz archive within the GeoMesa Cassandra distribution directory.

To install the plugins, extract the archive and copy the contents to the WEB-INF/lib directory of your GeoServer installation:

$ tar -xzvf \
  geomesa-cassandra_${VERSION}/dist/gs-plugins/geomesa-cassandra-gs-plugin_${VERSION}-install.tar.gz \
  -C /path/to/geoserver/webapps/geoserver/WEB-INF/lib

Next, install the JARs for Cassandra. By default, JARs will be downloaded from Maven central. You may override this by setting the environment variable GEOMESA_MAVEN_URL. If you do no have an internet connection you can download the JARs manually.

Edit the file geomesa-cassandra_${VERSION}/conf/dependencies.sh to set the version of Cassandra to match the target environment, and then run the script:

$ ./bin/install-dependencies.sh /path/to/geoserver/webapps/geoserver/WEB-INF/lib

Restart GeoServer after the JARs are installed.