We have one perl script that is opening DB connection and performaing insert DB operation.When duplicate entry Comming in query,Postgres forecfully killing process itself and in Postgres log "unexpected EOF on client connection" error is Comming.
This issue is not Comming every time.
We have found child script is killed by signal 13 SIGPIPE. When duplicate key violates error occured, script is killed but not all time.
I'm going to bet that the SIGPIPE is totally unrelated to having a duplicate key violation. You will need to provide much more detail of what you observe to figure this out.