Questions about PID of remote process

[钱晓明]

Hi, I have two questions about pid of remote process:

1. How do I know if the remote process identified by one PID is alive? I
know I can send a message to it, and receive response with timeout. But I
hope there is some way more conveniently.

2. Can the PID be reused in one node? If a process identified by one PID
died, then this PID can be used to identify other process created later?

Thanks!