Cassandra deployment fails with UnavailableException

[Chris Bunch]

I have the following ips.yaml file:

---
:master: 128.111.55.220
:appengine:
- 128.111.55.220
:database:
- 128.111.55.220
:open:
- 128.111.55.221

And AppScale doesn't run - complete log attached. Looks like a failure priming the database - Cassandra is used here. Would like to get this fixed so that I can verify that Neptune currently works.

[Chris Bunch (cgb-cs)]

Will leave the machines up overnight if you want to investigate.

[Chris Bunch (cgb-cs)]

Fix proposed with lp:~cgb-cs/appscale/tools-with-zero-db-detection - the ips.yaml above has only a single database node, which means it gets assigned as db_master. The tools were only checking for database nodes (of which db_master is not), so it counted a total of zero database nodes (since database means db_slave) and thus assigned replication = 0, which caused the unavailable exception thrown by Cassandra.

Fix committed causes tools to die if they detect zero database nodes and properly counts database masters as database nodes.