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_NATS_URL | NATS instance URL | nats://localhost:4222 |
| MF_CASSANDRA_WRITER_LOG_LEVEL | Log level for Cassandra writer (debug, info, warn, error) | error |
| MF_CASSANDRA_WRITER_PORT | Service HTTP port | 8180 |
| 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 |
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_NATS_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.