Mainflux.mainflux/consumers/writers/cassandra

Cassandra writer

Cassandra writer provides message repository implementation for Cassandra.

Configuration

The service is configured using the environment variables presented in the following table. Note that any unset variables will be replaced with their default values.

Variable	Description	Default
MF_BROKER_URL	Message broker instance URL	nats://localhost:4222
MF_CASSANDRA_WRITER_LOG_LEVEL	Log level for Cassandra writer (debug, info, warn, error)	info
MF_CASSANDRA_WRITER_PORT	Service HTTP port	9004
MF_CASSANDRA_WRITER_DB_CLUSTER	Cassandra cluster comma separated addresses	127.0.0.1
MF_CASSANDRA_WRITER_DB_KEYSPACE	Cassandra keyspace name	mainflux
MF_CASSANDRA_WRITER_DB_USER	Cassandra DB username
MF_CASSANDRA_WRITER_DB_PASS	Cassandra DB password
MF_CASSANDRA_WRITER_DB_PORT	Cassandra DB port	9042
MF_CASSANDRA_WRITER_CONFIG_PATH	Config file path with NATS subjects list, payload type and content-type	/config.toml
MF_JAEGER_URL	Jaeger server URL	localhost:6831
MF_SEND_TELEMETRY	Send telemetry to mainflux call home server	true

Deployment

The service itself is distributed as Docker container. Check the cassandra-writer service section in docker-compose to see how service is deployed.

To start the service, execute the following shell script:

# download the latest version of the service
git clone https://github.com/mainflux/mainflux

cd mainflux

# compile the cassandra writer
make cassandra-writer

# copy binary to bin
make install

# Set the environment variables and run the service
MF_BROKER_URL=[NATS instance URL] \
MF_CASSANDRA_WRITER_LOG_LEVEL=[Cassandra writer log level] \
MF_CASSANDRA_WRITER_PORT=[Service HTTP port] \
MF_CASSANDRA_WRITER_DB_CLUSTER=[Cassandra cluster comma separated addresses] \
MF_CASSANDRA_WRITER_DB_KEYSPACE=[Cassandra keyspace name] \
MF_CASSANDRA_READER_DB_USER=[Cassandra DB username] \
MF_CASSANDRA_READER_DB_PASS=[Cassandra DB password] \
MF_CASSANDRA_READER_DB_PORT=[Cassandra DB port] \
MF_CASSANDRA_WRITER_CONFIG_PATH=[Config file path with NATS subjects list, payload type and content-type] \
$GOBIN/mainflux-cassandra-writer

Using docker-compose

This service can be deployed using docker containers. Docker compose file is available in <project_root>/docker/addons/cassandra-writer/docker-compose.yml. In order to run all Mainflux core services, as well as mentioned optional ones, execute following command:

./docker/addons/cassandra-writer/init.sh

Usage

Starting service will start consuming normalized messages in SenML format.