Added snippets for 020_Distributed_Cluster

Author: clintongormley

020_Distributed_Cluster/10_Cluster_health.asciidoc

@@ -9,6 +9,7 @@ but the single most important one is the _cluster health_, which reports a
 --------------------------------------------------
 GET /_cluster/health
 --------------------------------------------------
+// SENSE: 020_Distributed_Cluster/10_Cluster_health.json
 
 which, on an empty cluster with no indices, will return something like:
 

020_Distributed_Cluster/15_Add_an_index.asciidoc

@@ -51,7 +51,7 @@ PUT /blogs
    }
 }
 --------------------------------------------------
-
+// SENSE: 020_Distributed_Cluster/15_Add_index.json
 
 [[cluster-one-node]]
 .A single-node cluster with an index

020_Distributed_Cluster/30_Scale_more.asciidoc

@@ -17,12 +17,10 @@ of replicas from the default of `1` to `2`:
 --------------------------------------------------
 PUT /blogs/_settings
 {
-   "index" : {
-      "number_of_replicas" : 2
-   }
+   "number_of_replicas" : 2
 }
 --------------------------------------------------
-
+// SENSE: 020_Distributed_Cluster/30_Replicas.json
 
 [[cluster-three-nodes-two-replicas]]
 .Increasing the `number_of_replicas` to 2

snippets/020_Distributed_Cluster/10_Cluster_health.json

@@ -0,0 +1,5 @@
+# Delete ALL DATA IN THE CLUSTER!
+DELETE /_all
+
+# Retrieve the cluster health
+GET /_cluster/health

snippets/020_Distributed_Cluster/15_Add_index.json

@@ -0,0 +1,14 @@
+# Delete ALL DATA IN THE CLUSTER!
+DELETE /_all
+
+# Create an index with 3 primary shards with 1 replica each
+PUT /blogs
+{
+   "settings" : {
+      "number_of_shards" : 3,
+      "number_of_replicas" : 1
+   }
+}
+
+# Retrieve the cluster health
+GET /_cluster/health

snippets/020_Distributed_Cluster/30_Replicas.json

@@ -0,0 +1,20 @@
+# Delete ALL DATA IN THE CLUSTER!
+DELETE /_all
+
+# Create an index with 3 primary shards with 1 replica each
+PUT /blogs
+{
+   "settings" : {
+      "number_of_shards" : 3,
+      "number_of_replicas" : 1
+   }
+}
+
+# Increae number of replicas to 2
+PUT /blogs/_settings
+{
+   "number_of_replicas" : 2
+}
+
+# Retrieve the cluster health
+GET /_cluster/health