cassandra

Cassandra reader

Cassandra reader 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.

Deployment

The service itself is distributed as Docker container. Check the cassandra-reader 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/absmach/magistrala

cd magistrala

# compile the cassandra
make cassandra-reader

# copy binary to bin
make install

# Set the environment variables and run the service
MG_CASSANDRA_READER_LOG_LEVEL=[Cassandra Service log level] \
MG_CASSANDRA_READER_HTTP_HOST=[Cassandra Service HTTP host] \
MG_CASSANDRA_READER_HTTP_PORT=[Cassandra Service HTTP port] \
MG_CASSANDRA_READER_HTTP_SERVER_CERT=[Cassandra Service HTTP server cert] \
MG_CASSANDRA_READER_HTTP_SERVER_KEY=[Cassandra Service HTTP server key] \
MG_CASSANDRA_CLUSTER=[Cassandra cluster comma separated addresses] \
MG_CASSANDRA_KEYSPACE=[Cassandra keyspace name] \
MG_CASSANDRA_USER=[Cassandra DB username] \
MG_CASSANDRA_PASS=[Cassandra DB password] \
MG_CASSANDRA_PORT=[Cassandra DB port] \
MG_THINGS_AUTH_GRPC_URL=[Things service Auth gRPC URL] \
MG_THINGS_AUTH_GRPC_TIMEOUT=[Things service Auth gRPC request timeout in seconds] \
MG_THINGS_AUTH_GRPC_CLIENT_TLS=[Things service Auth gRPC TLS enabled] \
MG_THINGS_AUTH_GRPC_CA_CERTS=[Things service Auth gRPC CA certificates] \
MG_AUTH_GRPC_URL=[Auth service gRPC URL] \
MG_AUTH_GRPC_TIMEOUT=[Auth service gRPC request timeout in seconds] \
MG_AUTH_GRPC_CLIENT_TLS=[Auth service gRPC TLS enabled] \
MG_AUTH_GRPC_CA_CERT=[Auth service gRPC CA certificates] \
MG_JAEGER_URL=[Jaeger server URL] \
MG_SEND_TELEMETRY=[Send telemetry to magistrala call home server] \
MG_CASSANDRA_READER_INSTANCE_ID=[Cassandra Reader instance ID] \
$GOBIN/magistrala-cassandra-reader

Using docker-compose

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

docker-compose -f docker/docker-compose.yml up -d
./docker/addons/cassandra-writer/init.sh
docker-compose -f docker/addons/casandra-reader/docker-compose.yml up -d

Usage

Service exposes HTTP API for fetching messages.

Note: Cassandra Reader doesn't support searching substrings from string_value, due to inefficient searching as the current data model is not suitable for this type of queries.