How to start an experiment
===
## 1.Introduce
There are few steps to start an new experiment of nni, here are the process.
<img src="./img/experiment_process.jpg" width="50%" height="50%" />
## 2.Details
### 2.1 Check environment
The first step to start an experiment is to check whether the environment is ready, nnictl will check if there is an old experiment running or the port of restfurl server is occupied.
NNICTL will also validate the content of config yaml file, to ensure the experiment config is in correct format.

### 2.2 Start restful server
After check environment, nnictl will start an restful server process to manage nni experiment, the default port is `51188`.

### 2.3 Check restful server
Before next steps, nnictl will check whether restful server is successfully started, or the starting process will stop and show error message.

### 2.4 Set experiment config
NNICTL need to set experiment config before start an experiment, experiment config includes the config values in config yaml file.

### 2.5 Check experiment cofig
NNICTL will ensure the request to set config is successfully executed.

### 2.6 Start WebUI
NNICTL will start a WebUI to show information,the default port of WebUI is `51188`.

### 2.7 Check WebUI
If WebUI is not successfully started, nnictl will give a warning information, and will continue to start experiment.

### 2.8 Start Experiment
This is the most import step of starting an nni experiment, nnictl will call restful server process to setup an experiment.

### 2.9 Check experiment
After start experiment, nnictl will check whether the experiment is correctly created, and show more information of this experiment to users.
