check all the addresses in pool initialization (#146)

* check all the addresses in pool initialization

* format code

Author: HarrisChu

client_test.go

@@ -195,7 +195,10 @@ func TestAuthentication(t *testing.T) {
 }
 
 func TestInvalidHostTimeout(t *testing.T) {
-	hostList := []HostAddress{
+	hostAdress := HostAddress{Host: address, Port: port}
+	hostList := []HostAddress{hostAdress}
+
+	invalidHostList := []HostAddress{
 		{Host: "192.168.100.125", Port: 3699}, // Invalid host
 		{Host: "127.0.0.1", Port: 3699},
 	}
@@ -207,9 +210,9 @@ func TestInvalidHostTimeout(t *testing.T) {
 	}
 	// close all connections in the pool
 	defer pool.Close()
-	err = pool.Ping(hostList[0], 1000*time.Millisecond)
+	err = pool.Ping(invalidHostList[0], 1000*time.Millisecond)
 	assert.EqualError(t, err, "failed to open transport, error: dial tcp 192.168.100.125:3699: i/o timeout")
-	err = pool.Ping(hostList[1], 1000*time.Millisecond)
+	err = pool.Ping(invalidHostList[1], 1000*time.Millisecond)
 	if err != nil {
 		t.Error("failed to ping 127.0.0.1")
 	}

connection_pool.go

@@ -68,6 +68,10 @@ func NewSslConnectionPool(addresses []HostAddress, conf PoolConfig, sslConfig *t
 
 // initPool initializes the connection pool
 func (pool *ConnectionPool) initPool() error {
+	if err := pool.checkAddresses(); err != nil {
+		return fmt.Errorf("failed to open connection, error: %s ", err.Error())
+	}
+
 	for i := 0; i < pool.conf.MinConnPoolSize; i++ {
 		// Simple round-robin
 		newConn := newConnection(pool.addresses[i%len(pool.addresses)])
@@ -344,3 +348,16 @@ func (pool *ConnectionPool) timeoutConnectionList() (closing []*connection) {
 	}
 	return
 }
+
+func (pool *ConnectionPool) checkAddresses() error {
+	var timeout = 3 * time.Second
+	if pool.conf.TimeOut != 0 && pool.conf.TimeOut < timeout {
+		timeout = pool.conf.TimeOut
+	}
+	for _, address := range pool.addresses {
+		if err := pool.Ping(address, timeout); err != nil {
+			return err
+		}
+	}
+	return nil
+}