Postgres could not receive data from client: Connection timed out

Question

Am a sql DBA, learning postgres..In postgres logs i often receive "could not receive data from client: Connection timed out" I do not have any other logs other than this

Am not sure how to troubleshoot? I check the application logs and DBs logs to compare the time but I could not notice any abnormalities.

can someone guide me how to trace this issue.

Thanks

Answer 1

A few possibilities:

• Your application closes connections without telling the PostgreSQL server it's doing so, by simply closing the network socket. It should send a PQclose(conn) if using libpq, or whatever equivalent your language/driver has.

• Network address translation timeouts on idle connections or other related network issues cause the TCP connections to break, so client and server lose communication with each other.

• A firewall on the client or server is blocking or disrupting connections after they're established (maybe malfunctioning IDS?)

• joanolo: IDS meaning Intrusion Detection?

Answer 2

iptables firewall may need a rule to be able to send out to the Postgres port you are connecting to:

iptables -L -n
Chain OUTPUT (policy DROP)
target prot opt source destination
ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:5432