fleet start fails arbitrarily on cluster with more than 500 nodes

[Vishant0031]

Test environment:
coreos version 835.11
fleetd version 0.11.5
etcd Version: 2.2.0

Fleet nodes:
700

Issue:
I am trying to start a fleet service on my cluster. I use command fleetctl start (diskinstall.service).
fleetctl list-machines shows 700 nodes.
and fleet service is a Global=true service and suppose to be launched on all the nodes.
When I start the service (fleetctl start diskinstall.service), service is started only on <700 nodes.
Sometimes the service is launched on ~400 nodes or ~500 and its very random.

At all the time fleetctl list-machines outputs 700 nodes.
etcd2 is also healthy all the time.
I have to repeat the fleetctl start command to overcome this issue.

Thanks.

[Vishant0031]

https://github.com/coreos/fleet/blob/master/Documentation/fleet-scaling.md

[waddles]

Does specifying an etcd endpoint as in #1650 make it better for you?