[WIP] TaoDB

Database for Event Sourcing

Install

See releases

$ sudo dpkg -i taodb.deb

Maven

<dependency>
    <groupId>com.github.puddingspudding</groupId>
    <artifactId>taodb</artifactId>
    <version>0.2.0</version>
</dependency>

Features

• Append only / Immutable
• Ordered Events
• Accessible via gRPC. See TaoDB.proto.
• Replication

Requirements

• Java 9

Design

In event sourcing, the requirements for the event store are to be append only and and able to provide all events since a specific timestamp or after a specfic event.

File

TaoDB appends incomming events, protobuf encoded, at the end of a file. In order to find all events after a given event id or since a timestamp an index (map from timestamp to file position) is held. The index is updated every second.

Event

An event consists of an Id and data (arbitrary bytes). The Id is a combination of timestamp (in seconds) and an UUID.

ToDo

• Deployment
  • Package
  • Start/Stop
  • Configuration
  • Error Logging
• Benchmarks
• Examples
• Tests
• Monitoring / Dashboard

Performance

Tested on AWS EC2 t2.2xlarge (8 Cores, 32GB)

• 1000 concurrent clients
• 10ms interval
• 1024 bytes/event

Run

Status

$ taodb status

Start/Stop

$ taodb start service1

$ taodb stop service1

Config

# Services
taodb.services=service1,service2

# Replication Services
taodb.replication.services=service1repli,service2repli

# Service 1
service1.network.port=6666
service1.storage.path=/var/lib/taodb/service1.db

# Service 2
service2.network.port=7777
service2.storage.path=/var/lib/taodb/service2.db

# Service 1 Replication
service1repli.network.port=6667
service1repli.storage.path=/var/lib/taodb/service1_repli.db
service1repli.master.host=127.0.0.1
service1repli.master.port=6666

# Service 2 Replication
service2repli.network.port=7778
service2repli.storage.path=/var/lib/taodb/service2_repli.db
service2repli.master.host=127.0.0.1
service2repli.master.port=7777