kvdb

Simple key-value storage. Implemented for experimental and educational purposes.

Building

Building with docker

The simplest (but not fastest for the first time ) way to build application from sources is to execute commands:

cd <path_to_kvdb>/docker docker-compose run build_all

To do this, You only will need installed docker daemon and docker-compose on your machine. You can download latest versions following by this links:

• docker desktop
• docker compose

Code was tested with Docker version 20.10.7 and docker-compose version 1.29.2 on Ubuntu 20.04.3 LTS

Building from command line

Required packets:

• g++
• libboost-system1.71-dev
• libboost-program-options1.71-dev
• libboost-log1.71-dev
• cmake

Build from sources:

cd <path_to_kvdb> ./build.sh

Build script will create directory <path_to_kvdb>/build and store all build artifacts in there

Using command line tools

KVDB Server

Executable file of server is kvdb_server. It accetpt next arguments:

• --port= optional, default value is 1524 specifies port to accept connections on. Server will start listen on address localhost:
• --file= optional, default value is ./memfile.map specifies path to memory mapped file where server will store it's data. One can specify not existing file - server will create new one.

Example of command:

./kvdb_server --port=5001 --file=./mymemfile.map

KVDB Client

Execution command format:

./kvdb_cli

named arguments:

• --hostname= required accepts address or name of remote KVDB server
• --port= optional, default value is 1524 port number of KVDB server to connect to

positional argument (command):

Command can consist of 2 to 3 separate strings:

• Command name. Possible values are: INSERT, UPDATE, GET, DELETE
• Key string placed in double qutes: "Some key"
• Value string placed in double quotes: "Some value"

Note: Key and value strings MUST NOT contain \0 symbol. Otherwise, it will cause wrong behaviour in string serialization-deserialization and, therefore string data corruption.

INSERT and UPDATE command accepts both Key and Value arguments, GET and UPDATE commands only accepts Key argument

Examples of usage:

./kvdb_cli --hostname=localhost --port=5001 INSERT "Some Key" "Some Value" ./kvdb_cli --hostname=localhost --port=5001 UPDATE "Some Key" "Some Other Value" ./kvdb_cli --hostname=localhost --port=5001 GET "Some Key" ./kvdb_cli --hostname=localhost --port=5001 DELETE "Some Key"

Running KVDB server in docker:

To run KVDB server using docker launch next commands:

cd <path_to_kvdb>/docker docker-compose up -d server

This command will run kvdb_server in docker environment and detach terminal from this process. Server will listening on localhost:5001

Test

There are integration test available in file <path_to_kvdb>/test.py This is simple python script performing next scenario:

• launching kvdb_server in docker
• creating number of key:value records in map
• restarting server
• checking that all previously created records are still contained by DB
• deleting all previously created values