fix add/remove node doc issue (#5269)

docs/manual/cluster-admin/how-to-add-and-remove-nodes.md

@@ -14,7 +14,7 @@ Log in to your dev box machine, find [the pre-kept folder `~/pai-deploy`](./inst
 
 Find the file `~/pai-deploy/kubespray/inventory/pai/hosts.yml`, and follow the steps below to modify it. 
 
-Supposing you want to add 2 worker nodes into your cluster and their hostnames are `a` and `b`.  Add these 2 nodes into the `hosts.yml`. An example:
+Supposing you want to add 2 worker nodes into your cluster and their hostnames are `new-worker-node-0` and `new-worker-node-1`.  Add these 2 nodes into the `hosts.yml`. An example:
 
 ```yaml
 all:
@@ -35,15 +35,15 @@ all:
       ...
 
 ############# Example start ################### 
-    a:
+    new-worker-node-0:
       ip: x.x.x.x
       access_ip: x.x.x.x
       ansible_host: x.x.x.x
       ansible_ssh_user: "username"
       ansible_ssh_pass: "your-password-here"
       ansible_become_pass: "your-password-here"
       ansible_ssh_extra_args: '-o StrictHostKeyChecking=no'
-    b:
+    new-worker-node-1:
       ip: x.x.x.x
       access_ip: x.x.x.x
       ansible_host: x.x.x.x
@@ -65,8 +65,8 @@ all:
         origin4:
 
 ############# Example start ################### 
-        a:
-        b:
+        new-worker-node-0:
+        new-worker-node-1:
 ############## Example end #################### 
 
     gpu:
@@ -75,8 +75,8 @@ all:
 
 ############# Example start ################### 
 #### If the worker doesn't have GPU, please don't add them here.
-        a:
-        b:
+        new-worker-node-0:
+        new-worker-node-1:
 ############## Example end #################### 
 
     etcd:
@@ -95,38 +95,38 @@ all:
 Go into folder `~/pai-deploy/kubespray/`, run:
 
 ```bash
-ansible-playbook -i inventory/pai/hosts.yml scale.yml -b --become-user=root -e "node=a,b" -e "@inventory/pai/openpai.yml"
+ansible-playbook -i inventory/pai/hosts.yml cluster.yml -b --become-user=root --limit=new-worker-node-0,new-worker-node-1 -e "@inventory/pai/openpai.yml"
 ```
 
-The nodes to add are specified with `-e` flag.
+The nodes to add are specified with the `--limit` flag.
 
 ### Update OpenPAI Service Configuration
 
 Find your [service configuration file `layout.yaml` and `services-configuration.yaml`](./basic-management-operations.md#pai-service-management-and-paictl) in  `~/pai-deploy/cluster-cfg`.
 
-- Add the new node into `machine-list` field in `layout.yaml`
+- Add the new node into `machine-list` field in `layout.yaml`, create a new `machine-sku` if necessary. Refer to [layout.yaml](./installation-guide.md#layoutyaml-format) for schema requirements.
 
 ```yaml
 machine-list:
-  - hostname: a
+  - hostname: new-worker-node--0
     hostip: x.x.x.x
     machine-type: xxx-sku
     pai-worker: "true"
 
-  - hostname: b
+  - hostname: new-worker-node-1
     hostip: x.x.x.x
     machine-type: xxx-sku
     pai-worker: "true"
 ```
 
 - If you are using hived scheduler, you should modify its setting in `services-configuration.yaml` properly. Please refer to [how to set up virtual clusters](./how-to-set-up-virtual-clusters.md) and the [hived scheduler doc](https://github.com/microsoft/hivedscheduler/blob/master/doc/user-manual.md) for details. If you are using Kubernetes default scheduler, you can skip this step.
 
-- Stop the service, push the latest configuration, and then start services:
+- Stop the service, push the latest configuration, and then start related services:
 
 ```bash
-./paictl.py service stop -n cluster-configuration hivedscheduler rest-server
+./paictl.py service stop -n cluster-configuration hivedscheduler rest-server job-exporter
 ./paictl.py config push -p <config-folder> -m service
-./paictl.py service start -n cluster-configuration hivedscheduler rest-server
+./paictl.py service start -n cluster-configuration hivedscheduler rest-server job-exporter
 ```
 
 If you have configured any PV/PVC storage, please confirm the added worker node meets the PV's requirements. See [Confirm Worker Nodes Environment](./how-to-set-up-storage.md#confirm-environment-on-worker-nodes) for details.
@@ -139,17 +139,17 @@ To remove nodes from the cluster, there is no need to modify `hosts.yml`.
 Go into `~/pai-deploy/kubespray/`, run
 
 ```bash
-ansible-playbook -i inventory/pai/hosts.yml remove-node.yml -b --become-user=root -e "node=a,b" -e "@inventory/pai/openpai.yml"
+ansible-playbook -i inventory/pai/hosts.yml remove-node.yml -b --become-user=root -e "node=worker-node-to-remove-0,worker-node-to-remove-1" -e "@inventory/pai/openpai.yml"
 ``` 
 
-The nodes to remove are specified with `-e` flag.
+The nodes to remove are specified with the `-e` flag.
 
 Modify the `layout.yaml` and `services-configuration.yaml`.
 
-Stop the service, push the latest configuration, and then start services:
+Stop the service, push the latest configuration, and then start related services:
 
 ```bash
-./paictl.py service stop -n cluster-configuration hivedscheduler rest-server
+./paictl.py service stop -n cluster-configuration hivedscheduler rest-server job-exporter
 ./paictl.py config push -p <config-folder> -m service
-./paictl.py service start -n cluster-configuration hivedscheduler rest-server
+./paictl.py service start -n cluster-configuration hivedscheduler rest-server job-exporter
 ```

docs/manual/cluster-admin/installation-guide.md

@@ -170,9 +170,7 @@ Please edit `layout.yaml` and a `config.yaml` file under `<pai-code-dir>/contrib
 These two files spedify the cluster layout and the customized configuration, respectively.
 The following is the format and example of these 2 files.
 
-#### Tips for China Users
-
-If you are a China user, before you edit these files, please refer to [here](./configuration-for-china.md) first.
+**Tips for China Users**: If you are a China user, before you edit these files, please refer to [here](./configuration-for-china.md) first.
 
 #### `layout.yaml` format