On 2/24/2017 1:37 PM, Tom Ekberg wrote:
I'm running postgres 9.6.2 (also happened on 9.3.14) and have a cron job that runs hourly that runs a program that does mostly postgres SELECTs on a different host. Occasionally I get email (not hourly) from the cron daemon that contains a stack trace that ends with this: sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) could not translate host name "db3.labmed.uw.edu" to address: Name or service not known It has happened about 9 times so far this month. I have one of our network people look into this but there is no real answer. I could use the IP address but I'd rather not. This problem only happens on one host. I moved the data from db2 to db3. I was getting similar emails regarding db2 which runs the older postgres.
what OS is this? what DNS servers are configured on that OS (in most all unix-flavored OS's, this is in /etc/resolv.conf ... on windows its in a network properties dialog buried 9 deep).
make sure *ALL* the listed name servers can resolve this internal hostname, by querying them each directly. do NOT mix private and public name servers, as the name resolver will only query one for a given query and only try another if the first server doesn't reply at all. if the first server replies ' host not known', that's taken as the answer.
Unix systems generally always query the first server listed in resolv.conf, and only queries the 2nd if the first isn't running at all. Windows, however, once it decides the first server isn't responding will continue to use the next one that does reply.
-- john r pierce, recycling bits in santa cruz -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
