AWS Aurora (PostgreSQL) queries with client address = null

Question

We are running a Django application with a AWS Aurora (PostgreSQL) database and are debugging some of our queries.

When we look at the running queries using following statement:

select
    pid,
    usename,
    datname,
    application_name,
    client_addr,
    query,
    now() - query_start
from
    pg_stat_activity
where
    usename <> 'rdsadmin';

We see a lot of duplicate queries where client_addr = <null>. The application_name and user however are the same (= our Django app). Most queries from our Django app include the correct client_addr.

Can someone explain why we see these duplicate queries that contain no client_addr?

Answer 1

From the official document:

IP address of the client connected to this backend. If this field is null, it indicates either that the client is connected via a Unix socket on the server machine or that this is an internal process such as autovacuum.