I am trying to setup a LogStash/Redis/ElasticSearch pipeline for centralized logging,I have a few questions,

1. I believe for this to work, you need a specific version of elasticsearch & logstash, is there a place where I can find a one-to-one mapping as to what versions of elasticsearch & logstash gel together.
2. This might sound very silly but, in the `elasticsearch.yml` file all lines start with `#`, do I need to get rid of the `#` for some minimum values.
3. Lastly I set up the whole pipeline, but I see the following error,

```
NativeException - org.elasticsearch.cluster.block.ClusterBlockException: blocked by: [SERVICE_UNAVAILABLE/1/state not recovered / initialized];[SERVICE_UNAVAILABLE/2/no master];:
    org/elasticsearch/cluster/block/ClusterBlocks.java:138:in `globalBlockedException'
    org/elasticsearch/cluster/block/ClusterBlocks.java:128:in `globalBlockedRaiseException'

```

Also I installed the elasticsearch head plugin, but it fails to load up, all I see is a spinning wheel in the Chrome tab.