metrictank clustering

[Dieterbe]

for grafana/metrictank#320

doesn't work very well yet. still getting some kafka and cassandra errors.

like

2016/09/15 16:31:27 [cassandra.go:106 Init()] [E] cassandra-idx failed to initialize cassandra table. gocql: no response received from cassandra within timeout period

and

Sarama] 2016/09/15 16:31:29 client/metadata found some partitions to be leaderless
[Sarama] 2016/09/15 16:31:29 client/metadata retrying after 250ms... (3 attempts remaining)
[Sarama] 2016/09/15 16:31:29 client/metadata found some partitions to be leaderless
[Sarama] 2016/09/15 16:31:29 client/metadata retrying after 250ms... (3 attempts remaining)
[Sarama] 2016/09/15 16:31:29 client/metadata fetching metadata for [mdm] from broker kafka:9092

and also some metrictank kafka-mdm errors about partitions not existing (yet?)

to be continued...

[Dieterbe]

fixed the kafka problem. will start testing this tomorrow morning (grafana/metrictank#320 (comment))