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Version: 3.7 (unsupported)

ScalarDB Server

ScalarDB Server is a gRPC server that implements ScalarDB interface. With ScalarDB Server, you can use ScalarDB 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 ScalarDB Server.

Install prerequisites​

ScalarDB Server is written in Java. So one of the following Java Development Kits (JDKs) is required to run it:

Install ScalarDB Server​

We have Docker images in our repository and zip archives of ScalarDB 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 ScalarDB Server​

You need a property file holding the configuration for ScalarDB Server. It contains two sections: ScalarDB Server configurations and underlying storage/database configurations.

#
# ScalarDB Server configurations
#

# Port number of ScalarDB Server. 60051 by default
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

# The maximum message size allowed to be received. If not specified, use the gRPC default value.
scalar.db.server.grpc.max_inbound_message_size=

# The maximum size of metadata allowed to be received. If not specified, use the gRPC default value.
scalar.db.server.grpc.max_inbound_metadata_size=

#
# Underlying storage/database configurations
#

# Comma separated contact points. For DynamoDB, the region is specified by this parameter.
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=

# Credential information to access the database. For Cosmos DB, username isn't used. For DynamoDB, AWS_ACCESS_KEY_ID is specified by the username and AWS_ACCESS_SECRET_KEY is specified by the password.
scalar.db.username=cassandra
scalar.db.password=cassandra

# Storage implementation. "cassandra" or "cosmos" or "dynamo" or "jdbc" or "grpc" can be set. Default storage is "cassandra".
scalar.db.storage=cassandra

# The type of the transaction manager. "consensus-commit" or "jdbc" or "grpc" can be set. The default is "consensus-commit".
scalar.db.transaction_manager=consensus-commit

# Isolation level used for ConsensusCommit. Either SNAPSHOT or SERIALIZABLE can be specified. SNAPSHOT is used by default.
scalar.db.consensus_commit.isolation_level=SNAPSHOT

# Serializable strategy used for ConsensusCommit transaction manager.
# Either EXTRA_READ or EXTRA_WRITE can be specified. EXTRA_READ is used by default.
# If SNAPSHOT is specified in the property "scalar.db.consensus_commit.isolation_level", this is ignored.
scalar.db.consensus_commit.serializable_strategy=

# This is only usable for Consensus Commit.
# If set to "true", Get and Scan operations results will contain transaction metadata. To see the transaction metadata columns details for a given table, you can use the `DistributedTransactionAdmin.getTableMetadata()`
# method which will return the table metadata augmented with the transaction metadata columns. Using this configuration can be useful to investigate transaction related issues.
# The default is false.
scalar.db.consensus_commit.include_metadata.enabled=false

Start ScalarDB Server​

Docker images​

For Docker images, you need to pull the ScalarDB Server image first:

$ docker pull ghcr.io/scalar-labs/scalardb-server:<version>

And then, you can start ScalarDB Server with the following command:

$ docker run -v <your local property file path>:/scalardb/server/database.properties.tmpl -d -p 60051:60051 -p 8080:8080 ghcr.io/scalar-labs/scalardb-server:<version>

You can also start it with DEBUG logging as follows:

$ docker run -v <your local property file path>:/scalardb/server/database.properties.tmpl -e SCALAR_DB_LOG_LEVEL=DEBUG -d -p 60051:60051 -p 8080:8080 ghcr.io/scalar-labs/scalardb-server:<version>

You can also start it with your custom log configuration as follows:

$ docker run -v <your local property file path>:/scalardb/server/database.properties.tmpl -v <your custom log4j2 configuration file path>:/scalardb/server/log4j2.properties.tmpl -d -p 60051:60051 -p 8080:8080 ghcr.io/scalar-labs/scalardb-server:<version>

You can also start it with environment variables as follows:

$ docker run --env SCALAR_DB_CONTACT_POINTS=cassandra --env SCALAR_DB_CONTACT_PORT=9042 --env SCALAR_DB_USERNAME=cassandra --env SCALAR_DB_PASSWORD=cassandra --env SCALAR_DB_STORAGE=cassandra -d -p 60051:60051 -p 8080:8080 ghcr.io/scalar-labs/scalardb-server:<version>

You can also start it with JMX as follows:

$ docker run -v <your local property file path>:/scalardb/server/database.properties.tmpl -e JAVA_OPTS="-Dlog4j.configurationFile=file:log4j2.properties -Djava.rmi.server.hostname=<your container hostname or IP address> -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote=true -Dcom.sun.management.jmxremote.local.only=false -Dcom.sun.management.jmxremote.port=9990 -Dcom.sun.management.jmxremote.rmi.port=9990 -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.authenticate=false" -d -p 60051:60051 -p 8080:8080 -p 9990:9990 ghcr.io/scalar-labs/scalardb-server:<version>

Zip archives​

For zip archives, you can start ScalarDB Server with the following commands:

$ unzip scalardb-server-<version>.zip
$ cd scalardb-server-<version>
$ export JAVA_OPTS="<your JVM options>"
$ bin/scalardb-server --config <your property file path>

Usage of the Java client of ScalarDB Server​

You can use the Java client of ScalarDB 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=<ScalarDB 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=60000

# The maximum message size allowed for a single gRPC frame. If not specified, use the gRPC default value.
scalar.db.grpc.max_inbound_message_size=

# The maximum size of metadata allowed to be received. If not specified, use the gRPC default value.
scalar.db.grpc.max_inbound_metadata_size=

Further reading​

Please see the following sample to learn ScalarDB Server further:

Please also see the following documents to learn how to deploy ScalarDB Server: