KV Store

Description

Proof of work for github.com/struckoff/sfcframework

Distributed key-value storage of geo data. It uses longitude and latitude extracted from key to find appropriate node on the space-filling curve. When new node appeared in the system, router automatically run redistributing process. It also works when each node responsible for distribution due to stateless mechanism of sfcframework which provides hashing functionality with same results on each node.

Router

/router service provides data balancing logic for the system.

It also provides HTTP API. Router could be run with store as one service or separate.

HTTP API

GET /nodes

Get list of nodes.

POST /put/:key

Example

echo "test-data" | http POST ":9190/put/{\"Lon\":-4,\"Lat\":-20}"      
HTTP/1.1 200 OK
Content-Length: 2
Content-Type: text/plain; charset=utf-8
Date: Thu, 08 Oct 2020 22:24:00 GMT

OK

Store binary data by given key.

GET /get/:keys

Example

http GET ":9190/get/{\"Lon\":-4,\"Lat\":-20}"
        
HTTP/1.1 200 OK
Content-Length: 59
Content-Type: text/plain; charset=utf-8

[
    {
        "Key": "{\"Lon\":-4,\"Lat\":-20}",
        "Value": "test-data"
    }
]

Return data by given slash separated keys.

GET /list

Return list of keys.

Config

config.json

{
  "Address": "0.0.0.0:9190",
  "RPCAddress": "127.0.0.1:9290",
  "Balancer":{
    "State": true,
    "Mode": "SFC",
    "DataMode": "geo",
    "SFC": {
      "Dimensions":2,
      "Size":256,
      "Curve": "morton"
    },
    "NodeHash": "geosfc"
  }
}

Store

Provides gRPC interface for bbolt DB to store data at the local file system.

Config

Mode

• standalone - will connect nodes between each other without external service.
• kvrouter - will try to use router as discovery service.
• consul - will use consul as discovery service.

config.json

{
  "Mode": "consul",
  "DBPath": "/data/data.db",
  "Power": 1,
  "Capacity": 100000,
  "Balancer":{
    "Mode": "SFC",
    "DataMode": "geo",
    "SFC": {
      "Dimensions":2,
      "Size":64,
      "Curve": "morton"
    },
    "NodeHash": "geosfc"
  },
  "Health": {
    "CheckInterval": "10s",
    "CheckTimeout": "10s",
    "DeregisterCriticalServiceAfter": "10s"
  },
  "Geo":{
    "Latitude":0.0,
    "Longitude":0.0
  },
  "KVRouter": {
    "Address": "127.0.0.1:9290"
  },
  "Consul": {
    "Service": "kvstore"
  }
}

Environment

Configuration is also possible with environment variables.

Example

KVSTORE_NAME=node-0
KVSTORE_MODE=kvrouter
KVSTORE_CAPACITY=1500
KVSTORE_KVROUTER_ADDRESS=localhost:9290
KVSTORE_RPC_ADDRESS=localhost:9293
KVSTORE_INFLUX_ADDRESS=http://127.0.0.1:8086
KVSTORE_GEO_LONGITUDE=-180
KVSTORE_GEO_LATITUDE=-90
KVSTORE_RPC_LATENCY=150ms
KVSTORE_DBPATH=/var/lib/kvstore/data/node-0/data.db