Odoo works fine but every now and then (on a daily basis) I get HTTP 500 error and have to restart postgresql manually because I get this db connection error in the odoo log file.  How can I debug this to figure out whats causing it?  I cant post images here but I can resume the log file entry which repeats over and over like this:

1. First there is a "could not connect to server...is the server accepting connections on unix domain socket: /var/run/postgresql/.s.PGSQL.5433.

2. Connection to db failed

3. /longpolling/poll HTTP...

4. error on request...