enhance tck setup

tests/common/nebula_service.py

@@ -368,7 +368,6 @@ def start(self):
         for p in self.all_processes:
             p.start()
 
-        time.sleep(3)
         config = Config()
         config.max_connection_pool_size = 20
         config.timeout = 60000
@@ -377,19 +376,33 @@ def start(self):
         # assert client_pool.init([("127.0.0.1", int(self.graphd_port))], config)
         ssl_config = get_ssl_config(self.is_graph_ssl, self.ca_signed)
         print("begin to add hosts")
-        assert client_pool.init(
-            [("127.0.0.1", self.graphd_processes[0].tcp_port)], config, ssl_config
-        )
-
-        cmd = (
-            "ADD HOSTS 127.0.0.1:"
-            + str(self.storaged_processes[0].tcp_port)
-            + " INTO NEW ZONE \"default_zone\""
-        )
-        print("add hosts cmd is {}".format(cmd))
+        ok = False
+        # wait graph is ready, and then add hosts
+        for _ in range(20):
+            try:
+                ok = client_pool.init(
+                    [("127.0.0.1", self.graphd_processes[0].tcp_port)],
+                    config,
+                    ssl_config,
+                )
+                if ok:
+                    break
+            except:
+                pass
+            time.sleep(1)
 
+        assert ok, "graph is not ready"
         # get session from the pool
         client = client_pool.get_session('root', 'nebula')
+
+        hosts = ",".join(
+            [
+                "127.0.0.1:{}".format(str(storaged.tcp_port))
+                for storaged in self.storaged_processes
+            ]
+        )
+        cmd = "ADD HOSTS {} INTO NEW ZONE \"default_zone\"".format(hosts)
+        print("add hosts cmd is {}".format(cmd))
         resp = client.execute(cmd)
         assert resp.is_succeeded(), resp.error_msg()
         client.release()