It is better to have a script to automatically handle the failure of vms.

Periodically scan status of vms, if not in active, do free floating ip and terminate instance.

there is script to delete instance and free floating ip:
https://opensource.ncsa.illinois.edu/bitbucket/projects/BD/repos/vm-elasticity/browse/purgeservers.sh

this is the status of vms for dts-dev, 4 of 11 are still active.

dts_dev_docker-17
docker-ubuntu-trusty-2016-11-10
192.168.5.35
Floating IPs:

141.142.211.82
m1.large ncsa-nebula Error nova None No State 11 hours, 8 minutes Disassociate Floating IP

dts_dev_docker-16
docker-ubuntu-trusty-2016-11-10
192.168.5.33
Floating IPs:

141.142.208.228
m1.large ncsa-nebula Active nova None Running 18 hours, 25 minutes
Create Snapshot

dts_dev_docker-15
docker-ubuntu-trusty-2016-11-10
192.168.5.32
Floating IPs:

141.142.208.226
m1.large ncsa-nebula Active nova None Running 18 hours, 45 minutes
Create Snapshot

dts_dev_docker-14
docker-ubuntu-trusty-2016-11-10
192.168.5.31
Floating IPs:

141.142.211.145
m1.large ncsa-nebula Error nova None No State 1 day Disassociate Floating IP

dts_dev_docker-13
docker-ubuntu-trusty-2016-11-10
192.168.5.3
Floating IPs:

141.142.211.96
m1.large ncsa-nebula Error nova None No State 1 day, 10 hours Disassociate Floating IP

dts_dev_docker-12
docker-ubuntu-trusty-2016-11-10
192.168.5.29
Floating IPs:

141.142.211.98
m1.large ncsa-nebula Error nova None No State 1 day, 18 hours Disassociate Floating IP

dts_dev_docker-11
docker-ubuntu-trusty-2016-11-10
192.168.5.26
Floating IPs:

141.142.208.225
m1.large ncsa-nebula Error nova None No State 1 day, 22 hours Disassociate Floating IP

dts_dev_docker-10
docker-ubuntu-trusty-2016-11-10
192.168.5.254
Floating IPs:

141.142.208.129
m1.large ncsa-nebula Suspended nova None Shut Down 1 day, 23 hours
Create Snapshot

dts_dev_docker-9
docker-ubuntu-trusty-2016-11-10
192.168.5.253
Floating IPs:

141.142.210.86
m1.large ncsa-nebula Error nova None No State 1 day, 23 hours Disassociate Floating IP

dts_dev_docker-8
docker-ubuntu-trusty-2016-11-10
192.168.5.252
Floating IPs:

141.142.211.77
m1.large ncsa-nebula Active nova None Running 1 day, 23 hours
Create Snapshot

dts_dev_docker-6
docker-ubuntu-trusty-2016-11-10
192.168.5.240
Floating IPs:

141.142.208.133
m1.large ncsa-nebula Active nova None Running 4 days, 6 hours