[metasrv] doc: explain how to examine the meta cluster state
@@ -58,3 +58,30 @@ And it will block until the `leave` request is done or an error occur.
See: `--raft-advertise-host`
- `--leave-id` specifies the node id to leave. It can be any id in a cluster.
+
+## 3. Examine cluster members
+
+At every step of adding or removing a node, the cluster state should be checked to ensure everything goes well.
+
+The `admin-api-address` defined in the config provides a administration HTTP service to examine cluster state:
+E.g., `curl -s localhost:28101/v1/cluster/nodes` will display the members in a cluster:
+
+```json
+[
+ {
+ "name": "1",
+ "endpoint": {
+ "addr": "localhost",
+ "port": 28103
+ }
+ },
+ {
+ "name": "2",
+ "endpoint": {
+ "addr": "localhost",
+ "port": 28203
+ }
+ }
+]
+```
+
