diff --git a/examples/cluster2.lua b/examples/cluster2.lua
index 69f67438..3b7a2c02 100644
--- a/examples/cluster2.lua
+++ b/examples/cluster2.lua
@@ -20,8 +20,10 @@ skynet.start(function()
 	-- test snax service
 	skynet.timeout(300,function()
 		cluster.reload {
+			db = false,	-- db is down
 			db3 = "127.0.0.1:2529"
 		}
+		print(pcall(cluster.call, "db", sdb, "GET", "a"))	-- db is down
 	end)
 	local pingserver = cluster.snax("db3", "pingserver")
 	print(pingserver.req.ping "hello")
diff --git a/service/clusterd.lua b/service/clusterd.lua
index 8d971e9e..3196820a 100644
--- a/service/clusterd.lua
+++ b/service/clusterd.lua
@@ -33,19 +33,25 @@ local function open_channel(t, key)
 		ct.namequery = co
 		skynet.error("Wating for cluster node [".. key.."]")
 		skynet.wait(co)
-		address = assert(node_address[key])
+		address = node_address[key]
+		assert(address ~= nil)
 	end
-	local host, port = string.match(address, "([^:]+):(.*)$")
-	local c = sc.channel {
-		host = host,
-		port = tonumber(port),
-		response = read_response,
-		nodelay = true,
-	}
-	local succ, err = pcall(c.connect, c, true)
-	if succ then
-		t[key] = c
-		ct.channel = c
+	local succ, err, c
+	if address then
+		local host, port = string.match(address, "([^:]+):(.*)$")
+		c = sc.channel {
+			host = host,
+			port = tonumber(port),
+			response = read_response,
+			nodelay = true,
+		}
+		succ, err = pcall(c.connect, c, true)
+		if succ then
+			t[key] = c
+			ct.channel = c
+		end
+	else
+		err = "cluster node [" .. key .. "] is down."
 	end
 	connecting[key] = nil
 	for _, co in ipairs(ct) do
@@ -68,7 +74,7 @@ local function loadconfig(tmp)
 		end
 	end
 	for name,address in pairs(tmp) do
-		assert(type(address) == "string")
+		assert(address == false or type(address) == "string")
 		if node_address[name] ~= address then
 			-- address changed
 			if rawget(node_channel, name) then
@@ -92,7 +98,8 @@ end
 function command.listen(source, addr, port)
 	local gate = skynet.newservice("gate")
 	if port == nil then
-		addr, port = string.match(node_address[addr], "([^:]+):(.*)$")
+		local address = assert(node_address[addr], addr .. " is down")
+		addr, port = string.match(address, "([^:]+):(.*)$")
 	end
 	skynet.call(gate, "lua", "open", { address = addr, port = port })
 	skynet.ret(skynet.pack(nil))