Memdclient use of closed network connection

Here is our log:

2018/03/26 10:47:58 |DEBU| [secret_path/main.go:37 main.main] connect to couchbase://192.168.115.94,192.168.115.92,192.168.115.88,192.168.115.90,192.168.115.89,192.168.115.93,192.168.115.95,192.168.115.91,192.168.115.87,192.168.115.220 host=secret_host name=main
2018/03/26 10:47:58 |ERRO| [secret_path/conf/logger.go:33 secret_path/conf.logger.Log] memdClient read failure: read tcp 10.10.10.104:36391->192.168.115.94:11210: use of closed network connection host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocbcore.v7/memdclient.go:217
2018/03/26 10:47:58 |ERRO| [secret_path/conf/logger.go:33 secret_path/conf.logger.Log] Failed to shut down client connection (close tcp 10.10.10.104:36391->192.168.115.94:11210: use of closed network connection) host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocbcore.v7/memdclient.go:257
2018/03/26 10:47:58 |ERRO| [secret_path/conf/logger.go:33 secret_path/conf.logger.Log] memdClient read failure: read tcp 10.10.10.104:36393->192.168.115.94:11210: use of closed network connection host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocbcore.v7/memdclient.go:217
2018/03/26 10:47:58 |ERRO| [secret_path/conf/logger.go:33 secret_path/conf.logger.Log] Failed to shut down client connection (close tcp 10.10.10.104:36393->192.168.115.94:11210: use of closed network connection) host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocbcore.v7/memdclient.go:257
2018/03/26 10:47:58 |DEBU| [secret_path/server/server.go:183 secret_path/server.StartThriftServer] Thrift server started : 0.0.0.0:8092 host=secret_host name=StartThriftServer
2018/03/26 10:48:08 |INFO| [secret_path/conf/logger.go:29 secret_path/conf.logger.Log] Threshold Log: host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocb.v1/thresholdlogtracer.go:191
2018/03/26 10:48:18 |INFO| [secret_path/conf/logger.go:29 secret_path/conf.logger.Log] Threshold Log: host=secret_host name=cb-sdk stack=/go/src/secret_path/vendor/gopkg.in/couchbase/gocb.v1/thresholdlogtracer.go:191

1、I confirm that 192.168.115.94:11210 is reachable.
2、I adjust the addr order, let 192.168.115.92 be first, the log shows 192.168.115.92: 11210 related info.
3、couchbase go sdk version:1.3.4

I tried cmd blew, and it shows it is connected.

root@secret_host:~# netstat -anp | grep tcp | grep "192.168.115.94"
tcp        0      0 10.10.10.104:37237      192.168.115.94:11210    ESTABLISHED 4328/ms_unique
tcp        0      0 10.10.10.104:37257      192.168.115.94:11210    ESTABLISHED 4328/ms_unique

Any idea about what caused this ERRO message?

Is there anybody has the same issue?