Merge pull request #14 from jielinxu/branch-0.5.0

# Contributing to Milvus

First of all, thanks for taking the time to contribute to Milvus! It's people like you that help Milvus come to fruition.

First of all, thanks for taking the time to contribute to Milvus! It's people like you that help Milvus come to fruition. :tada:

The following are a set of guidelines for contributing to Milvus. Following these guidelines helps contributing to this project easy and transparent. These are mostly guideline, not rules. Use your best judgment, and feel free to propose changes to this document in a pull request.

Before you make any contributions, make sure you follow this list.

- Read [Contributing to Milvus](CONTRIBUTING.md).

- Check if the changes are consistent with the [coding style](CONTRIBUTING.md#coding-style).

- Run [unit tests](CONTRIBUTING.md#run-unit-test).

- Check if the changes are consistent with the [coding style](CONTRIBUTING.md#coding-style), and format your code accordingly.

- Run [unit tests](CONTRIBUTING.md#run-unit-test-with-code-coverage) and check your code coverage rate.

## What contributions can I make?

- 120-character line length

- Camel-Cased file names

### Format code

## Run unit test

Install clang-format

```shell

$ sudo apt-get install clang-format

$ rm cmake_build/CMakeCache.txt

```

Check code style

```shell

$ ./build.sh -l

```

To format the code

```shell

$ cd cmake_build

$ make clang-format

```

## Run unit test with code coverage

We use Google Test framework for test running.

To run unit test for Milvus under C++, please use the following command:

Before submitting your PR, make sure you have run unit test, and your code coverage rate is >= 90%.

Install lcov

```shell

# Run unit test for Milvus

$ ./build.sh -u

$ sudo apt-get install lcov

```

Run unit test and generate code for code coverage check

```shell 

$ ./build.sh -u -c

```

Run MySQL docker

```shell 

docker pull mysql:latest

docker run -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 -d mysql:latest

```

Run code coverage

```shell  

$ ./coverage.sh -u root -p 123456 -t 127.0.0.1

```

Or start your own MySQL server, and then run code coverage

```shell

$ ./coverage.sh -u ${MYSQL_USERNAME} -p ${MYSQL_PASSWORD} -t ${MYSQL_SERVER_IP}

```

# Welcome to Milvus

Firstly, welcome, and thanks for your interest in [Milvus](https://milvus.io)! No matter who you are, what you do, we greatly appreciate your contribution to help us reinvent data science with Milvus.

Firstly, welcome, and thanks for your interest in [Milvus](https://milvus.io)! ​​No matter who you are, what you do, we greatly appreciate your contribution to help us reinvent data science with Milvus.

## What is Milvus

- Intelligent index

  With a “Decide Your Own Algorithm” approach, you can embed machine learning and advanced algorithms into Milvus without the headache of complex data engineering or migrating data between disparate systems. Milvus is built on optimized indexing algorithm based on quantization indexing, tree-based and graph indexing methods.

  With a "Decide Your Own Algorithm" approach, you can embed machine learning and advanced algorithms into Milvus without the headache of complex data engineering or migrating data between disparate systems. Milvus is built on optimized indexing algorithm based on quantization indexing, tree-based and graph indexing methods.

- Strong scalability

  The data is stored and computed on a distributed architecture. This lets you scale data sizes up and down without redesigning the system.

## Architecture

![Milvus_arch](https://github.com/milvus-io/docs/blob/branch-0.5.0/assets/milvus_arch.png)

![Milvus_arch](https://github.com/milvus-io/docs/blob/branch-0.5.0/assets/milvus_arch.jpg)

## Get started

When the build is completed, all the stuff that you need in order to run Milvus will be installed under `[Milvus root path]/core/milvus`.

#### Code format and linting

Install clang-format

```shell

$ sudo apt-get install clang-format

$ rm cmake_build/CMakeCache.txt

```

Check code style

```shell

$ ./build.sh -l

```

To format the code

```shell

$ cd cmake_build

$ make clang-format

```

#### Run unit test

```shell

$ ./build.sh -u

```

#### Run code coverage

Install lcov

```shell

$ sudo apt-get install lcov

```

```shell  

$ ./build.sh -u -c

```

Run MySQL docker

```shell 

docker pull mysql:latest

docker run -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123456 -d mysql:latest

```

Run code coverage

```shell  

$ ./coverage.sh -u root -p 123456 -t 127.0.0.1

```

Or start your own MySQL server, and then run code coverage

```shell

$ ./coverage.sh -u ${MYSQL_USERNAME} -p ${MYSQL_PASSWORD} -t ${MYSQL_SERVER_IP}

```

#### Launch Milvus server

```shell