Active_primary_shards spontaneously doubled?

Hi, I have a four-node cluster configured with 8 primary shards and 1 replica. I'm using the Java client, but the equivalent yml file would look like this on each node:

cluster.name: clusterA
node.name: ca1
node.master: true
node.data: true
index.number_of_shards: 8
index.number_of_replicas: 1
path.data: /analyticsData
bootstrap.mlockall: true
discovery.zen.minimum_master_nodes: 3
discovery.zen.ping.multicast.enabled: false
discovery.zen.ping.unicast.hosts: ["node1[9300-9399]", "node2[9300-9399]", "node3[9300-9399]", "node4[9300-9399]"]

Of course node.name would differ per node.

Once three nodes are up (due to minimum_master_nodes setting), all is well. Fourth node comes up, and all is well; _cluster/health says:

{
    cluster_name: "clusterA",
    status: "green",
    timed_out: false,
    number_of_nodes: 4,
    number_of_data_nodes: 4,
    active_primary_shards: 8,
    active_shards: 16,
    relocating_shards: 0,
    initializing_shards: 0,
    unassigned_shards: 0
}

At some point node "ca4" is killed (kill -9, or some other possibly unfriendly way), and restarted. The results:

{
    cluster_name: "clusterA",
    status: "green",
    timed_out: false,
    number_of_nodes: 4,
    number_of_data_nodes: 4,
    active_primary_shards: 16,
    active_shards: 32,
    relocating_shards: 0,
    initializing_shards: 0,
    unassigned_shards: 0
}

????????

How is this possible? How do we spontaneously have double primary shards? Where do I even start looking for clues to this situation? This is ES 1.1.1.

Thanks.

Does the number of primaries drop or does it stay the same?

I'd suggest an upgrade to 1.5.2, 1.1.1 is getting a little old.

Well my question turned out to be dumb. I was assisting another team, and lacked complete information. Turns out they were starting one of the nodes against an existing path.data, which of course had two indices. Hence 8 shards * 2 indices = 16 primary shards. Sigh. Thanks.