Communication device and non-transitory computer-readable medium storing computer readable instruction for communication device that operate in parallel in a first mode and a second mode

A non-transitory computer-readable recording medium storing computer-readable instructions for a communication device:

• the computer-readable instructions, when executed by a processor of the communication device, cause the communication device to:
• in a case where a process executing instruction is sent to a notification server from a terminal device, receive a process executing notification from the notification server;
• and
• in a case where the process executing notification is received from the notification server, execute a predetermined process,
• wherein the process executing notification is received by:
• operating in parallel in a first mode and a second mode;
• sending a polling signal to the notification server in the first mode;
• in a case where the polling signal is sent to the notification server after the process executing instruction has been sent to the notification server from the terminal device, receiving the process executing notification which is a response to the polling signal from the notification server;
• establishing a connection of server-push type between the communication device and the notification server in the second mode;
• and
• in a case where the process executing instruction is sent to the notification server from the terminal device in a state where the connection is established, receiving the process executing notification from the notification server by using the connection.