When decreasing component nodes, there will be duplicate or stable components

#### Question desc
for example, before deploy, there has three invoker nodes on current env.
```
invoker0
invoker1
invoker2
```
Then, i will decrease invoker nodes to
```
invoker0
invoker1
```
so, `invoker2` is not in this deployment.

But on currently codes, there has no `inspection mechanism` to delete the `invoker2`,
It seems `invoker2` container already exist.

#### More complicated situation
before deploy, the invokers like below
```
[invokers]
invoker0 ansible_host=ip1
invoker1 ansible_host=ip2
invoker2 ansible_host=ip3
```
Then, i will redeploy using below
```
[invokers]
invoker0 ansible_host=ip3
invoker1 ansible_host=ip1
invoker3 ansible_host=ip2
```
just the ip's index is changed.

#### How to solve?
Currently, i have no good idea to solve.
My target is that implement it automatically rather than hand judgments

As far as i know, controller has url `http://:10001/invokers` to access all invokers.
May be we can compare the result with the current deploy nodes.
if found some node is not deploy any more, we can remove it first using `-e mode=clean`
but `url /invokers's return content` doesn't include the `deploy node's hosts or ip info`.
```
{"invoker1":"up","invoker2":"up","invoker5":"down","invoker4":"down","invoker3":"down","invoker0":"down"}
```

I don't know whether has other good idea