Shard metadata never be expired

[jvshahid]

I tried automatic shard expiration with the following database configuration:

[
{
  "database": "test",
  "spaces": [
    {
      "name": "everything",
      "retentionPolicy": "10m",
      "shardDuration": "1m",
      "regex": "/.*/",
      "replicationFactor": 2,
      "split": 1
    }
  ]
}
]

Then, old shards were successfully dropped:

[07/18/14 11:43:36] [INFO] DATASTORE: dropping shard /home/shugo/work/influxdb/cluster_test/1/db/shard_db_v2/00003

However, "GET /cluster/shards" returns dropped shards.

I guess shard metadata should be removed by updateOrRemoveShard() in all nodes, or shards should be dropped through Raft.

[pauldix]

Dropping of a shard from a server should go through raft. That way all the other servers in the cluster will remove the reference of that shard being kept on a given server.

So drop shard 1 from server 1, or whatever. If the drop is for the local server id, then actually delete it from disk. If the drop is the last server to have a copy of the shard, remove the shard entirely from the cluster config.

[shugo]

@pauldix I've created PR #803 by which expired shards are dropped through raft. Could you check it?