[RFC] Adds Ping() to client/scheduler/server (#585)

* [RFC] Adds Ping() to client/scheduler/server

* Checks for scheduler state closed

client.go

@@ -419,6 +419,11 @@ func (c *Client) EnqueueContext(ctx context.Context, task *Task, opts ...Option)
 	return newTaskInfo(msg, state, opt.processAt, nil), nil
 }
 
+// Ping performs a ping against the redis connection.
+func (c *Client) Ping() error {
+	return c.broker.Ping()
+}
+
 func (c *Client) enqueue(ctx context.Context, msg *base.TaskMessage, uniqueTTL time.Duration) error {
 	if uniqueTTL > 0 {
 		return c.broker.EnqueueUnique(ctx, msg, uniqueTTL)

scheduler.go

@@ -336,3 +336,14 @@ func (s *Scheduler) clearHistory() {
 		}
 	}
 }
+
+// Ping performs a ping against the redis connection.
+func (s *Scheduler) Ping() error {
+	s.state.mu.Lock()
+	defer s.state.mu.Unlock()
+	if s.state.value == srvStateClosed {
+		return nil
+	}
+
+	return s.rdb.Ping()
+}

server.go

@@ -759,7 +759,7 @@ func (srv *Server) Shutdown() {
 func (srv *Server) Stop() {
 	srv.state.mu.Lock()
 	if srv.state.value != srvStateActive {
-		// Invalid calll to Stop, server can only go from Active state to Stopped state.
+		// Invalid call to Stop, server can only go from Active state to Stopped state.
 		srv.state.mu.Unlock()
 		return
 	}
@@ -770,3 +770,16 @@ func (srv *Server) Stop() {
 	srv.processor.stop()
 	srv.logger.Info("Processor stopped")
 }
+
+// Ping performs a ping against the redis connection.
+//
+// This is an alternative to the HealthCheckFunc available in the Config object.
+func (srv *Server) Ping() error {
+	srv.state.mu.Lock()
+	defer srv.state.mu.Unlock()
+	if srv.state.value == srvStateClosed {
+		return nil
+	}
+
+	return srv.broker.Ping()
+}