Inconsistent availability information on Web UI

[danielmewes]

The web UI seems to use different methods to figure out table/replica availability in different places. This sometimes leads to inconsistent data (see the attached image).

Also I often noticed that on the overview for a specific table, right under Statistics, it would say "Live" next to a green icon, even if some of the shards are actually down. In this example, the table was in fact not available, neither for outdated nor up-to-date reads.

@neumino: Ideas? :-)

[neumino]

Hum, looking at the code, we just look at the blueprint and check if there is enough available replicas.
By available replica, we mean a replica that is on a machine that is not down.

I'll update this code to use the same as on the Replication Status view (checking the blueprint and directory).

[neumino]

Up in review 1189 assigned to @mglukhovsky
Branch michel_1756_live_status

A table is "Live" only if every shards have enough replicas up to date to meet the number of acks required, which mean a table can be "Live" even if it's replicating.

The number of master/replicas reachable in the profile view (first section) is the number of shards/replicas own by a machine that we can reach.
I renamed shards/replicas reachable in the sections below to shards/replicas available since in this case we check if we can use them or not.

I also fixed a bug for unsatisfiable goal in my commit in case universe is master (we forgot to add 1 in this case).

[neumino]

Merged in next.as 33b3190
Ship 1.12