pgpool stream主备模式，断开备节点后，为什么会pgpool重启所有子进程

搭建了pgpool stream主备异步流复制模式，测试的时候发现，当备节点手动关掉之后，pgpool会将子进程全部杀死然后重新创建子进程。

pgpool版本为 3.4.3

log如下：

LOG: reading and processing packets
2016-01-06 16:39:53: pid 27732: DETAIL: postmaster on DB node 1 was shutdown by administrative command
2016-01-06 16:39:53: pid 27732: LOG: received degenerate backend request for node_id: 1 from pid [27732]
2016-01-06 16:39:53: pid 27701: LOG: starting degeneration. shutdown host node147(5432)
2016-01-06 16:39:53: pid 27701: LOG: Restart all children
2016-01-06 16:39:53: pid 27706: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27702: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27704: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27705: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27703: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27708: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27709: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27707: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27712: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27711: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27710: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27713: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27718: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27719: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27714: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27716: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27723: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27717: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27724: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27720: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27715: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27722: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27721: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27727: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27726: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27725: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27701: LOG: failover: set new primary node: 0
2016-01-06 16:39:53: pid 27732: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27728: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27731: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27730: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27733: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27729: LOG: child process received shutdown request signal 3
2016-01-06 16:39:53: pid 27701: LOG: failover: set new master node: 0
failover done. shutdown host node147(5432)2016-01-06 16:39:53: pid 27701: LOG: failover done. shutdown host node147(5432)
2016-01-06 16:39:53: pid 27735: LOG: worker process received restart request
2016-01-06 16:39:54: pid 27734: LOG: restart request received in pcp child process
2016-01-06 16:39:54: pid 27701: LOG: PCP child 27734 exits with status 256 in failover()
2016-01-06 16:39:54: pid 27701: LOG: fork a new PCP child pid 27769 in failover()
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27702 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27702 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27703 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27703 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27704 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27704 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27705 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27705 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27706 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27706 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27707 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27707 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27708 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27708 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27709 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27709 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27710 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27710 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27711 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27711 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27712 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27712 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27713 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27713 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27714 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27714 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27715 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27715 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27716 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27716 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27717 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27717 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27718 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27718 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27719 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27719 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27720 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27720 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27721 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27721 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27722 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27722 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27723 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27723 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27724 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27724 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27725 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27725 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27726 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27726 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27727 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27727 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27728 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27728 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27729 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27729 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27730 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27730 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27731 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27731 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27732 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27732 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27733 exits with status 0
2016-01-06 16:39:54: pid 27701: LOG: child process with pid: 27733 exited with success and will not be restarted
2016-01-06 16:39:54: pid 27701: LOG: worker child process with pid: 27735 exits with status 256
2016-01-06 16:39:54: pid 27701: LOG: fork a new worker child process with pid: 27770