MY DEAR PLEASE IF YOU WANT ANSWER ONLY ONE QUESTION, JUST ANSWER Q1. BUT IF YOU ANSWER BOTH OF QUESTION I WILL BE MORE HAPPAY

Q1. A process P sends messages to another process Q infinitely often via a unidirectional channel. The communication channel c is not FIFO. Assume now that there exists a known upper bound of T seconds on the message propagation delay along with channel c, messages are sent out at a uniform rate of r messages per second by process P, and process Q is faster than process P. What is the smallest size buffer that process Q is required to maintain if it wants to accept the messages in the same order in which P sent them?

Q2. Suggest a design for a notification mailbox service that is intended to store notifications on behalf of multiple subscribers, allowing subscribers to specify when they require notifications to be delivered.

1. Explain how subscribers that are not always active can make use of the service you describe.
2. How will the service deal with subscribers that crash while they have delivery turned on?