Scalar DB server
Scalar DB server is a gRPC server that implements Scalar DB interface. With Scalar DB server, you can use Scalar DB features from multiple programming languages that are supported by gRPC.
Currently, we provide only a Java client officially, and we will support other language clients officially in the future. Of course, you can generate language-specific client stubs by yourself. However, note that it is not necessarily straightforward to implement a client since it's using a bidirectional streaming RPC in gRPC, and you need to be familiar with it.
This document explains how to install and use Scalar DB server.
Install prerequisites
Scalar DB server is written in Java. So the following software is required to run it.
- Oracle JDK 8 (OpenJDK 8) or higher
Install Scalar DB server
We have Docker images in our repository and zip archives of Scalar DB server available in releases.
If you are interested in building from source, run the following command:
./gradlew installDist
Of course, you can archive the jar and libraries by ./gradlew distZip and so on.
Configure Scalar DB Server
You need a property file holding the configuration for Scalar DB Server. It contains two sections, Server configurations and Underlining storage/database configurations.
#
# Server configurations
#
# Port number of Scalar DB server. 60051 by deafult
#scalar.db.server.port=60051
# Prometheus exporter port. Use 8080 if this is not given. Prometheus exporter will not be started if a negative number is given.
#scalar.db.server.prometheus_exporter_port=8080
#
# Underlining storage/database configurations
#
# Comma separated contact points
scalar.db.contact_points=localhost
# Port number for all the contact points. Default port number for each database is used if empty.
#scalar.db.contact_port=9042
# Credential information to access the database
#scalar.db.username=cassandra
#scalar.db.password=cassandra
# Storage implementation. Either cassandra or cosmos or dynamo or jdbc can be set. Default storage is cassandra.
#scalar.db.storage=cassandra
Start Scalar DB server
For Docker images, you can start Scalar DB server with the following commands:
docker pull ghcr.io/scalar-labs/scalardb-server:<version>
docker run -v <your local property file path>:/scalardb/server/database.properties -d ghcr.io/scalar-labs/scalardb-server:<version>
For zip archives, you can start Scalar DB server with the following commands:
unzip scalardb-server-<version>.zip
cd scalardb-server-<version>
bin/scalardb-server --config <your property file path>
Usage of the Java client of Scalar DB server
You can use the Java client of Scalar DB server in almost the same way as other storages/databases.
The difference is that you need to set scalar.db.storage and scalar.db.transaction_manager to grpc in your client side property file.
# Comma separated contact points
scalar.db.contact_points=<Scalar DB server host>
# Port number for all the contact points
scalar.db.contact_port=60051
# Storage implementation
scalar.db.storage=grpc
# The type of the transaction manager
scalar.db.transaction_manager=grpc
# The deadline duration for gRPC connections. The default is 60000 milliseconds (60 seconds)
#scalar.db.grpc.deadline_duration_millis=