text: --case_1:
  CREATE NODE cn01_1 WITH (TYPE='coordinator', HOST='172.16.0.3', PORT=15431);
  CREATE NODE cn01 WITH (TYPE='coordinator', HOST='172.16.0.3', PORT=15432, CLUSTER='tbase_cluster');
  CREATE NODE cn01 WITH (TYPE='coordinator', HOST='172.16.0.3', PORT=15433, CLUSTER='pgxc_cluster_slave');
  
  --expect:
  --cn01_1 and cn01 with(15432) in tbase_cluster, and cn01 with(15433) in pgxc_cluster_slave;
  select node_name,node_type,node_port,node_host,node_cluster_name from pgxc_node where node_name in ('cn01', 'cn01_1')order by oid;
  
  --case_2:
  ALTER NODE cn01 WITH (HOST='10.112.111.147', PORT=30003, CLUSTER='tbase_cluster');
  --expect:
  --error, CLUSTER could not be modified.
  select node_name,node_type,node_port,node_host,node_cluster_name from pgxc_node where node_name in ('cn01', 'cn01_1')order by oid;
  
  
  --case_3:
  ALTER NODE cn01 WITH (HOST='10.112.111.147', PORT=30003);
  ALTER NODE cn01 in pgxc_cluster_slave WITH (HOST='10.112.111.147', PORT=30003);
  --expect:
  --ok
  select node_name,node_type,node_port,node_host,node_cluster_name from pgxc_node where node_name in ('cn01', 'cn01_1')order by oid;
  
  --case_4:
  drop node cn01;
  --expect:
  --only cn01 in tbase_cluster dropped.
  select node_name,node_type,node_port,node_host,node_cluster_name from pgxc_node where node_name in ('cn01', 'cn01_1')order by oid;
  
  --case_5:
  drop node cn01_1 in tbase_cluster;
  drop node cn01 in pgxc_cluster_slave;
  --expect
  --cn01 in pgxc_cluster_slave dropped, cn01_1 dropped.
  select node_name,node_type,node_port,node_host,node_cluster_name from pgxc_node where node_name in ('cn01', 'cn01_1')order by oid;
  
  
  