I have mogodb cluster with 4 nodes, all nodes work on standard 27017 port. I found weird things in my mongod.log on a secondary node:
{"t":{"$date":"2022-03-26T23:22:34.593+03:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn12132","msg":"Connection ended","attr":{"remote":"<PRIMARY_IP>:42994","connectionId":12132,"connectionCount":143}}
{"t":{"$date":"2022-03-26T23:22:35.065+03:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn12133","msg":"Connection ended","attr":{"remote":"<PRIMARY_IP>:43004","connectionId":12133,"connectionCount":142}}
{"t":{"$date":"2022-03-26T23:22:35.106+03:00"},"s":"I", "c":"NETWORK", "id":22944, "ctx":"conn12129","msg":"Connection ended","attr":{"remote":"<PRIMARY_IP>:41906","connectionId":12129,"connectionCount":141}}
{"t":{"$date":"2022-03-26T23:22:41.555+03:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"<PRIMARY_IP>:57280","connectionId":12202,"connectionCount":142}}
{"t":{"$date":"2022-03-26T23:22:41.560+03:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn12202","msg":"client metadata","attr":{"remote":"<PRIMARY_IP>:57280","client":"conn12202","doc":{"driver":{"name":"PyMongo","version":"4.0.1"},"os":{"type":"Linux","name":"Linux","architecture":"x86_64","version":"5.4.0-67-generic"},"platform":"CPython 3.9.4.final.0"}}}
{"t":{"$date":"2022-03-26T23:22:41.611+03:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"<PRIMARY_IP>:57296","connectionId":12203,"connectionCount":143}}
{"t":{"$date":"2022-03-26T23:22:41.612+03:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn12203","msg":"client metadata","attr":{"remote":"<PRIMARY_IP>:57296","client":"conn12203","doc":{"driver":{"name":"PyMongo","version":"4.0.1"},"os":{"type":"Linux","name":"Linux","architecture":"x86_64","version":"5.4.0-67-generic"},"platform":"CPython 3.9.4.final.0"}}}
{"t":{"$date":"2022-03-26T23:22:41.755+03:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"<PRIMARY_IP>:57312","connectionId":12204,"connectionCount":144}}
{"t":{"$date":"2022-03-26T23:22:41.756+03:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn12204","msg":"client metadata","attr":{"remote":"<PRIMARY_IP>:57312","client":"conn12204","doc":{"driver":{"name":"PyMongo","version":"4.0.1"},"os":{"type":"Linux","name":"Linux","architecture":"x86_64","version":"5.4.0-67-generic"},"platform":"CPython 3.9.4.final.0"}}}
{"t":{"$date":"2022-03-26T23:22:41.807+03:00"},"s":"I", "c":"NETWORK", "id":22943, "ctx":"listener","msg":"Connection accepted","attr":{"remote":"<PRIMARY_IP>:57324","connectionId":12205,"connectionCount":145}}
{"t":{"$date":"2022-03-26T23:22:41.808+03:00"},"s":"I", "c":"NETWORK", "id":51800, "ctx":"conn12205","msg":"client metadata","attr":{"remote":"<PRIMARY_IP>:57324","client":"conn12205","doc":{"driver":{"name":"PyMongo","version":"4.0.1"},"os":{"type":"Linux","name":"Linux","architecture":"x86_64","version":"5.4.0-67-generic"},"platform":"CPython 3.9.4.final.0"}}}
I see some weird connections on different ports, and i don't understand what is it. Is it normal?
Servers are protected by ufw firewall, but my nodes have full access (on any port) to each other. Port 27017 is opened from outside.
This is /etc/mongod.conf, it's the same on all nodes:
storage:
dbPath: /mnt/data
net:
port: 27017
bindIp: 0.0.0.0
security:
authorization: enabled
keyFile: /mnt/data/mongodb.key
replication:
replSetName: rs0
systemLog:
path: /mnt/data/mongod.log
destination: file
logAppend: true
operationProfiling:
mode: slowOp
slowOpThresholdMs: 50
ufw stauts:
22 LIMIT Anywhere
27017 ALLOW Anywhere
Anywhere ALLOW <MY_ANOTHER_SERVER_IP>
Anywhere ALLOW <MY_ANOTHER_SERVER_IP>
Anywhere ALLOW <MY_ANOTHER_SERVER_IP>
Anywhere ALLOW <MY_ANOTHER_SERVER_IP>
22 (v6) LIMIT Anywhere (v6)
27017 (v6) ALLOW Anywhere (v6)
