pg_rewind could not find previous WAL record at 0/4B000060: invalid record length at 0/4B000060: wanted 24, got 0

Hi, all

I have 1 master and 2 slave PostgreSQL servers named e.g. server1(master), server2(slave) and server3(slave)

OS: Ubuntu 16.04
Postgresql version is 9.6.

Consider server1 down, then I touched a trigger file to server2, and then from server3 I run pg_rewind,

But still get below errors:

root(at)server3#: systemctl stop postgresql(at)9(dot)6-main(dot)service
root(at)server3#: runuser -s /bin/bash postgres -c '/usr/lib/postgresql/9.6/bin/pg_rewind --target-pgdata /var/lib/postgresql/9.6/main/ --source-server="host=10.10.4.7 port=5432 user=postgres dbname=postgres"'
servers diverged at WAL position 0/4B000060 on timeline 17

could not find previous WAL record at 0/4B000060: invalid record length at 0/4B000060: wanted 24, got 0
Failure, exiting

What is wrong here? Thanks.