Online Saltstack Minions on Azure losses connection with Master on DigitalOcean

I have a salt 2016.11.3 (Carbon) playground with a master in DigitalOcean and 4 minions in Azure (three ubuntu and 1 windows).

After a while ubuntu minions are not responding to salt -t 30 '*' test.ping but they are online ( I can ssh into them )

Restarting the master systemctl restart salt-master or minions systemctl restart salt-minion seems to bring minions back for a while.

Things checked:

• Azure machines are put to sleep and only woken up on external events ✗
• The network between the two clouds is very slow ✗
• salt master machine is too small ✗
• salt minions do not ask master for "work" ✗
• salt-master hangs for some reason
• salt-minion communication error ✔

Also after restart I get a double response from re-added nodes but I think this is a cache problem because it disappears after some time (cache invalidation).

It seems like is a communication error. There is an older 2013 bug report on saltstack github repo and someone states in comments that AWS and Azure load balancers don't respect TCP keepalives.

Suggested solutions:

1. add a cron to ping minions each minute
2. change some keepalive settings in Azure minions config file

Until now solution #2 works for me.

tcp_keepalive: True
tcp_keepalive_idle: 60