ChronicleDB on a Raft

Build

mvn clean
mvn frontend:yarn
mvn frontend:webpack
mnv package

Compile protos after change

mvn clean
mnv package

Package may fail as generated java classes change after protos are compiled, but they should be indexed by the IDE regardless.

Configuration

Either via the application.properties or run arguments.

Cluster Startup

PEERS=n1:localhost:6000,n2:localhost:6001,n3:localhost:6002
ID=n0
HTTP_PORT=8080
META_PORT=6000
REPLICATION_PORT=6050

./mvnw spring-boot:run -Dspring-boot.run.arguments="\
--node-id={ID} \
--server.address=localhost \
--server.port={HTTP_PORT} \
--metadata-port={META_PORT} \
--replication-port={REPLICATION_PORT} \
--storage=/tmp/raft-demo/{ID} \
--peers={PEERS}"

Example

./mvnw spring-boot:run -Dspring-boot.run.arguments="\
--node-id=n1 \
--server.address=localhost \
--server.port=8080 \
--metadata-port=6000 \
--replication-port=6050 \
--storage=/tmp/raft-demo/n1 \
--peers=n0:localhost:6000,n1:localhost:6001,n2:localhost:6002"

From JAR

java -jar target/raft-log-replication-demo-0.0.1-SNAPSHOT.jar \
--node-id={ID} \
--server.address=localhost \
--server.port={HTTP_PORT} \
--metadata-port={META_PORT} \
--replication-port={REPLICATION_PORT} \
--storage=/tmp/raft-demo/{ID} \
--peers={PEERS}"

Example Cluster

PEERS=n1:localhost:6000,n2:localhost:6001,n3:localhost:6002

ID=n1
java -jar target/raft-log-replication-demo-0.0.1-SNAPSHOT.jar \
--node-id=${ID} \
--server.address=localhost \
--server.port=8080 \
--metadata-port=6000 \
--replication-port=6050 \
--storage=/tmp/raft-demo/${ID} \
--peers=${PEERS}

ID=n2
java -jar target/raft-log-replication-demo-0.0.1-SNAPSHOT.jar \
--node-id=${ID} \
--server.address=localhost \
--server.port=8081 \
--metadata-port=6001 \
--replication-port=6051 \
--storage=/tmp/raft-demo/${ID} \
--peers=${PEERS}

ID=n3
java -jar target/raft-log-replication-demo-0.0.1-SNAPSHOT.jar \
--node-id=${ID} \
--server.address=localhost \
--server.port=8082 \
--metadata-port=6002 \
--replication-port=6052 \
--storage=/tmp/raft-demo/${ID} \
--peers=${PEERS}

Docker

See the docker-compose as well as the Dockerfile.

Provisioning a partition

In general, a new partition of any state machine (any that implements the StateMachine interface) can be instantiated using the REST API:

POST http://localhost:8080/api/cluster-manager/partitions
Content-Type: application/json

{
  "stateMachineClassName": "de.umr.raft.raftlogreplicationdemo.replication.impl.statemachines.EventStoreStateMachine",
  "partitionName": "events",
  "replicationFactor": 3
}

For event stores, there is a convenience method to instantiate a new stream on its own partition:

POST http://localhost:8080/api/event-store/streams
Content-Type: application/json

{
  "streamName": "demo-event-store",
  "schema": [
    {
      "name": "SYMBOL",
      "type": "STRING",
      "properties": {}
    },
    {
      "name": "SECURITYTYPE",
      "type": "INTEGER",
      "properties": {}
    },
    {
      "name": "LASTTRADEPRICE",
      "type": "FLOAT",
      "properties": {}
    }
  ]
}

Note that the schema is currently ignored, since it is hardcoded. The implementation of the dynamic schema invocation is currently pending.

Roadmap

Make a library out of the Apache Ratis on-top abstractions

One sub-goal is to create a standalone, high-level abstraction of Apache Ratis to enable developers to build high available applications with strong consistent replication in record time.

Test coverage

There is currently little to no test coverage. We want everything to be tested.