Node with non-kv services is not autofailed over when a server group fails.

1. Create a 9 nodes vulcan cluster with following configuration

• Group 1: 2 KV nodes and 1 node with index, FTS and query services
• Group 2: 2 KV nodes and 1 node with index, FTS and query services
• Group 3: 2 KV nodes and 1 node with index, FTS and query services

2. Enable autofailover with server groups on the cluster
3. Introduce failures in group 3 by stopping the couchbase servers
4. Wait for failover of nodes

The KV nodes in the group are failed over as expected. But the non-kv node is not failed over along with the KV nodes. The logs does say trying to failover server group 3 but only with the KV nodes. According to design docs, the non-kv node must be failed over automatically too since the cluster is well balanced.

The above steps can be reproduced by running the following system test.
1. Start a job on http://qa.sc.couchbase.com/job/component_systest_launcher/ with following parameters

• Version number: Latest build or latest weekly build
• test:  -test tests/rebalance/test_servergroup_failover.yml -scope tests/rebalance/scope_servergroup_failover.yml
• Provider: file:centos_component.yml
• duration: 3600

Keep the rest of the parameters as default. Please contact me if you need to start a run on the system test boxes to reproduce the issue again for live debugging.