That depends on the nature of the program. We use error and critical for server software. If there is a protocol violation on a particular connection, log an er

That depends on the nature of the program. We use error and critical for server software. If there is a protocol violation on a particular connection, log an error and drop the connection, but otherwise continues. If the `accept` system call fails that's critical and the program shuts down. Depending on what we're doing there may be other critical operations, but some software doesn't have any.