CommandRequestRemoteIpHeaderAppender
Appends the client address as remote_ip: the first non-blank entry of the first X-Forwarded-For header, taken as is, otherwise the remote address of the connection.
The remote address is written as its address literal (hostString), never resolved by a reverse DNS lookup: the appender runs on the event loop, where a lookup blocks every request on that loop. Since 9.2.3; earlier versions wrote the reverse-resolved host name.