Merge pull request #599 from drmingdrmer/30-example-remove-node

Refactor: add example of removing nodes

examples/raft-kv-memstore/test-cluster.sh

@@ -102,7 +102,7 @@ echo "Changing membership from [1] to 3 nodes cluster: [1, 2, 3]"
 echo
 rpc 21001/change-membership '[1, 2, 3]'
 sleep 1
-echo "Membership changed"
+echo 'Membership changed to [1, 2, 3]'
 sleep 1
 
 echo "Get metrics from the leader again"
@@ -131,10 +131,36 @@ echo "Read from node 3"
 echo
 rpc 21003/read  '"foo"'
 
-echo "Killing all nodes in 3s..."
+
+echo "Changing membership from [1,2,3] to [3]"
+echo
+rpc 21001/change-membership '[3]'
+sleep 1
+echo 'Membership changed to [3]'
+sleep 1
+
+echo "Get metrics from the node-3"
+sleep 1
+echo
+rpc 21003/metrics
+sleep 1
+
+
+echo "Write foo=zoo on node-3"
 sleep 1
-echo "Killing all nodes in 2s..."
+echo
+rpc 21003/write '{"Set":{"key":"foo","value":"zoo"}}'
 sleep 1
-echo "Killing all nodes in 1s..."
+echo "Data written"
 sleep 1
+
+echo "Read foo=zoo from node-3"
+sleep 1
+echo "Read from node 3"
+echo
+rpc 21003/read  '"foo"'
+echo
+
+
+echo "Killing all nodes..."
 kill

examples/raft-kv-memstore/tests/cluster/test_cluster.rs

@@ -195,5 +195,27 @@ async fn test_cluster() -> anyhow::Result<()> {
         Ok(_) => panic!("MUST return CheckIsLeaderError"),
     }
 
+    // --- Remove node 1,2 from the cluster.
+
+    println!("=== change-membership to 3, ");
+    let _x = client.change_membership(&btreeset! {3}).await?;
+
+    tokio::time::sleep(Duration::from_millis(1_000)).await;
+
+    println!("=== metrics after change-membership to {{3}}");
+    let x = client.metrics().await?;
+    assert_eq!(&vec![vec![3]], x.membership_config.get_joint_config());
+
+    println!("=== write `foo=zoo` to node-3");
+    let _x = client3
+        .write(&ExampleRequest::Set {
+            key: "foo".to_string(),
+            value: "zoo".to_string(),
+        })
+        .await?;
+
+    println!("=== read `foo=zoo` to node-3");
+    let got = client3.read(&"foo".to_string()).await?;
+    assert_eq!("zoo", got);
     Ok(())
 }