Use Echo method to send inactivity probe

This commit client's Echo method to send inactivity probe as it can be made
as a time bound call so that rpc lock is freed in advance. This would make
disconnect happen immediately when current ovsdb leader is accidentally gone
away and reconnects with new ovsdb leader.

Signed-off-by: Periyasamy Palanisamy <[email protected]>

client/client.go

@@ -1197,19 +1197,8 @@ func (o *ovsdbClient) handleClientErrors(stopCh <-chan struct{}) {
 	}
 }
 
-func (o *ovsdbClient) sendEcho(args []interface{}, reply *[]interface{}) *rpc2.Call {
-	o.rpcMutex.RLock()
-	defer o.rpcMutex.RUnlock()
-	if o.rpcClient == nil {
-		return nil
-	}
-	return o.rpcClient.Go("echo", args, reply, make(chan *rpc2.Call, 1))
-}
-
 func (o *ovsdbClient) handleInactivityProbes() {
 	defer o.handlerShutdown.Done()
-	echoReplied := make(chan string)
-	var lastEcho string
 	stopCh := o.stopCh
 	trafficSeen := o.trafficSeen
 	for {
@@ -1218,50 +1207,15 @@ func (o *ovsdbClient) handleInactivityProbes() {
 			return
 		case <-trafficSeen:
 			// We got some traffic from the server, restart our timer
-		case ts := <-echoReplied:
-			// Got a response from the server, check it against lastEcho; if same clear lastEcho; if not same Disconnect()
-			if ts != lastEcho {
-				o.Disconnect()
-				return
-			}
-			lastEcho = ""
 		case <-time.After(o.options.inactivityTimeout):
-			// If there's a lastEcho already, then we didn't get a server reply, disconnect
-			if lastEcho != "" {
-				o.Disconnect()
-				return
-			}
 			// Otherwise send an echo
-			thisEcho := fmt.Sprintf("%d", time.Now().UnixMicro())
-			args := []interface{}{"libovsdb echo", thisEcho}
-			var reply []interface{}
-			// Can't use o.Echo() because it blocks; we need the Call object direct from o.rpcClient.Go()
-			call := o.sendEcho(args, &reply)
-			if call == nil {
+			ctx, cancel := context.WithTimeout(context.Background(), o.options.timeout)
+			err := o.Echo(ctx)
+			if err != nil {
+				o.logger.V(3).Error(err, "server echo reply error")
 				o.Disconnect()
-				return
 			}
-			lastEcho = thisEcho
-			go func() {
-				// Wait for the echo reply
-				select {
-				case <-stopCh:
-					return
-				case <-call.Done:
-					if call.Error != nil {
-						// RPC timeout; disconnect
-						o.logger.V(3).Error(call.Error, "server echo reply error")
-						o.Disconnect()
-					} else if !reflect.DeepEqual(args, reply) {
-						o.logger.V(3).Info("warning: incorrect server echo reply",
-							"expected", args, "reply", reply)
-						o.Disconnect()
-					} else {
-						// Otherwise stuff thisEcho into the echoReplied channel
-						echoReplied <- thisEcho
-					}
-				}
-			}()
+			cancel()
 		}
 	}
 }