3.2+4.0版本日志中出现大量莫名其妙的记录，找不到原因，麻烦帮忙看看

2018/03/25 23:45:27 backend.go:262: [WARN] backend conn [0xc436f60660] to 172.168.10.45:9901, db-6 round-[228913]
2018/03/25 23:45:27 backend.go:262: [WARN] backend conn [0xc436f604e0] to 172.168.10.45:9901, db-4 round-[228913]
2018/03/25 23:45:27 backend.go:335: [WARN] backend conn [0xc436f60660] to 172.168.10.45:9901, db-6 writer-[228913] exit
[error]: error resp: ERR invalid DB index
2018/03/25 23:45:27 backend.go:335: [WARN] backend conn [0xc436f604e0] to 172.168.10.45:9901, db-4 writer-[228913] exit
[error]: error resp: ERR invalid DB index
2018/03/25 23:45:27 session.go:85: [INFO] session [0xc4202ce200] closed: {"ops":5,"create":1521992727,"lastop":1521992727,"remote":"172.168.10.42:53758"}, error: EOF
2018/03/25 23:45:27 session.go:85: [INFO] session [0xc430fa3500] closed: {"ops":7,"create":1521992727,"lastop":1521992727,"remote":"172.168.10.42:53760"}, error: EOF
2018/03/25 23:45:27 session.go:78: [INFO] session [0xc437c5bb00] create: {"ops":0,"create":1521992727,"remote":"172.168.10.42:53762"}
2018/03/25 23:45:27 session.go:78: [INFO] session [0xc437c5bb80] create: {"ops":0,"create":1521992727,"remote":"172.168.10.42:53765"}
2018/03/25 23:45:28 backend.go:262: [WARN] backend conn [0xc431c7b080] to 172.168.10.36:9901, db-9 round-[228925]
2018/03/25 23:45:28 backend.go:262: [WARN] backend conn [0xc431c7b440] to 172.168.10.36:9901, db-14 round-[228925]
2018/03/25 23:45:28 backend.go:335: [WARN] backend conn [0xc431c7b080] to 172.168.10.36:9901, db-9 writer-[228925] exit
[error]: error resp: ERR invalid DB index
2018/03/25 23:45:28 backend.go:335: [WARN] backend conn [0xc431c7b440] to 172.168.10.36:9901, db-14 writer-[228925] exit
[error]: error resp: ERR invalid DB index
2018/03/25 23:45:28 backend.go:262: [WARN] backend conn [0xc436f602a0] to 172.168.10.45:9901, db-1 round-[228913]
2018/03/25 23:45:28 backend.go:335: [WARN] backend conn [0xc436f602a0] to 172.168.10.45:9901, db-1 writer-[228913] exit
[error]: error resp: ERR invalid DB index

类似这种的记录不停的出现，感觉像是请求了多个db，但我每个节点的 database 都是设置成1的~~
所有相关的地方也找了，实在找不到原因，请求大神帮助。。。